Feature/refactor api (#34)

* Refactor error handling and comments

* Refactor and improve error handling and logs

api/api/codes.go

@@ -1,9 +0,0 @@
-package api
-
-// API codes used in guardian node.
-// The same codes are used to facilitate portability to the new api.
-const (
-	InvalidArgument = 3
-	NotFound        = 5
-	Internal        = 13
-)

api/errors/isof.go

@@ -1,12 +0,0 @@
-package errors
-
-import "errors"
-
-func IsOf(received error, targets ...error) bool {
-	for _, t := range targets {
-		if errors.Is(received, t) {
-			return true
-		}
-	}
-	return false
-}

api/go.mod

@@ -3,27 +3,26 @@ module github.com/wormhole-foundation/wormhole-explorer/api
 go 1.19
 
 require (
+	github.com/ansrivas/fiberprometheus/v2 v2.4.1
 	github.com/certusone/wormhole/node v0.0.0-20220907133901-8e231501b6cd
 	github.com/gofiber/fiber/v2 v2.39.0
+	github.com/ipfs/go-log/v2 v2.5.1
 	github.com/spf13/viper v1.13.0
 	go.mongodb.org/mongo-driver v1.10.3
+	go.uber.org/zap v1.22.0
 )
 
 require (
 	github.com/andybalholm/brotli v1.0.4 // indirect
-	github.com/ansrivas/fiberprometheus/v2 v2.4.1 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/btcsuite/btcd v0.22.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/ethereum/go-ethereum v1.10.6 // indirect
 	github.com/fsnotify/fsnotify v1.5.4 // indirect
 	github.com/gofiber/adaptor/v2 v2.1.29 // indirect
-	github.com/gogo/protobuf v1.3.3 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/golang/snappy v0.0.3 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
-	github.com/ipfs/go-log v1.0.5 // indirect
-	github.com/ipfs/go-log/v2 v2.5.1 // indirect
 	github.com/klauspost/compress v1.15.12 // indirect
 	github.com/magiconair/properties v1.8.6 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
@@ -32,7 +31,6 @@ require (
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/montanaflynn/stats v0.0.0-20171201202039-1bf9dbcd8cbe // indirect
-	github.com/opentracing/opentracing-go v1.2.0 // indirect
 	github.com/pelletier/go-toml v1.9.5 // indirect
 	github.com/pelletier/go-toml/v2 v2.0.5 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
@@ -55,7 +53,6 @@ require (
 	github.com/youmark/pkcs8 v0.0.0-20181117223130-1be2e3e5546d // indirect
 	go.uber.org/atomic v1.10.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
-	go.uber.org/zap v1.22.0 // indirect
 	golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d // indirect
 	golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4 // indirect
 	golang.org/x/sys v0.1.0 // indirect

api/go.sum

@@ -83,6 +83,7 @@ github.com/aws/aws-sdk-go-v2/service/sso v1.1.1/go.mod h1:SuZJxklHxLAXgLTc1iFXbE
 github.com/aws/aws-sdk-go-v2/service/sts v1.1.1/go.mod h1:Wi0EBZwiz/K44YliU0EKxqTCJGUfYTWXrrBwkq736bM=
 github.com/aws/smithy-go v1.1.0/go.mod h1:EzMw8dbp/YJL4A5/sbhGddag+NPT7q084agLbB9LgIw=
 github.com/benbjohnson/clock v1.1.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
+github.com/benbjohnson/clock v1.3.0 h1:ip6w0uFQkncKQ979AypyG0ER7mqUSBdKLOgAle/AT8A=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
@@ -105,7 +106,6 @@ github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA
 github.com/certusone/wormhole/node v0.0.0-20220907133901-8e231501b6cd h1:j/D2a0Hvs+JBKteCTFGhi9f7MA0SaDE+BPFoGNqSENo=
 github.com/certusone/wormhole/node v0.0.0-20220907133901-8e231501b6cd/go.mod h1:hbEdpBxPoBplIJ+PMVitVGX5194g+Opd7dvONcxhykQ=
 github.com/cespare/cp v0.1.0/go.mod h1:SOGHArjBr4JWaSDEVpWpo/hNg6RoKrls6Oh40hiwW+s=
-github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/cespare/xxhash/v2 v2.1.2 h1:YRXhKfTDauu4ajMg1TPgFO5jnlC2HCbmLXMcTG5cbYE=
@@ -173,8 +173,6 @@ github.com/gofiber/adaptor/v2 v2.1.25/go.mod h1:gOxtwMVqUStB5goAYtKd+hSvGupdd+aR
 github.com/gofiber/adaptor/v2 v2.1.29 h1:JnYd6fbqVM9D4zPchk+kg89PfxyuKqZKhBWGQDHfKH4=
 github.com/gofiber/adaptor/v2 v2.1.29/go.mod h1:z4mAV9mMsUgIEVGGS5Ii6ZMTJq4VdV1KWL1JAbsZdUA=
 github.com/gofiber/fiber/v2 v2.36.0/go.mod h1:tgCr+lierLwLoVHHO/jn3Niannv34WRkQETU8wiL9fQ=
-github.com/gofiber/fiber/v2 v2.38.1 h1:GEQ/Yt3Wsf2a30iTqtLXlBYJZso0JXPovt/tmj5H9jU=
-github.com/gofiber/fiber/v2 v2.38.1/go.mod h1:t0NlbaXzuGH7I+7M4paE848fNWInZ7mfxI/Er1fTth8=
 github.com/gofiber/fiber/v2 v2.39.0 h1:uhWpYQ6EHN8J7FOPYbI2hrdBD/KNZBC5CjbuOd4QUt4=
 github.com/gofiber/fiber/v2 v2.39.0/go.mod h1:Cmuu+elPYGqlvQvdKyjtYsjGMi69PDp8a1AY2I5B2gM=
 github.com/gofrs/uuid v3.3.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
@@ -271,9 +269,6 @@ github.com/influxdata/promql/v2 v2.12.0/go.mod h1:fxOPu+DY0bqCTCECchSRtWfc+0X19y
 github.com/influxdata/roaring v0.4.13-0.20180809181101-fc520f41fab6/go.mod h1:bSgUQ7q5ZLSO+bKBGqJiCBGAl+9DxyW63zLTujjUlOE=
 github.com/influxdata/tdigest v0.0.0-20181121200506-bf2b5ad3c0a9/go.mod h1:Js0mqiSBE6Ffsg94weZZ2c+v/ciT8QRHFOap7EKDrR0=
 github.com/influxdata/usage-client v0.0.0-20160829180054-6d3895376368/go.mod h1:Wbbw6tYNvwa5dlB6304Sd+82Z3f7PmVZHVKU637d4po=
-github.com/ipfs/go-log v1.0.5 h1:2dOuUCB1Z7uoczMWgAyDck5JLb72zHzrMnGnCNNbvY8=
-github.com/ipfs/go-log v1.0.5/go.mod h1:j0b8ZoR+7+R99LD9jZ6+AJsrzkPbSXbZfGakb5JPtIo=
-github.com/ipfs/go-log/v2 v2.1.3/go.mod h1:/8d0SH3Su5Ooc31QlL1WysJhvyOTDCjcCZ9Axpmri6g=
 github.com/ipfs/go-log/v2 v2.5.1 h1:1XdUzF7048prq4aBjDQQ4SL5RxftpRGdXhNRwKSAlcY=
 github.com/ipfs/go-log/v2 v2.5.1/go.mod h1:prSpmC1Gpllc9UYWxDiZDreBYw7zp4Iqp1kOLU9U5UI=
 github.com/jackpal/go-nat-pmp v1.0.2-0.20160603034137-1fa385a6f458/go.mod h1:QPH045xvCAeXUZOxsnwmrtiCoxIr9eob+4orBN1SBKc=
@@ -302,8 +297,6 @@ github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6
 github.com/klauspost/compress v1.4.0/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
 github.com/klauspost/compress v1.13.6/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
 github.com/klauspost/compress v1.15.0/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
-github.com/klauspost/compress v1.15.1 h1:y9FcTHGyrebwfP0ZZqFiaxTaiDnUrGkJkI+f583BL1A=
-github.com/klauspost/compress v1.15.1/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
 github.com/klauspost/compress v1.15.9/go.mod h1:PhcZ0MbTNciWF3rruxRgKxI5NkcHHrHUDtV4Yw2GlzU=
 github.com/klauspost/compress v1.15.12 h1:YClS/PImqYbn+UILDnqxQCZ3RehC9N318SU3kElDUEM=
 github.com/klauspost/compress v1.15.12/go.mod h1:QPwzmACJjUTFsnSHH934V6woptycfrDDJnH7hvFVbGM=
@@ -371,8 +364,6 @@ github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1y
 github.com/opentracing/opentracing-go v1.0.2/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/opentracing/opentracing-go v1.0.3-0.20180606204148-bd9c31933947/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
-github.com/opentracing/opentracing-go v1.2.0 h1:uEJPy/1a5RIPAJ0Ov+OIO8OxWu77jEv+1B0VhjKrZUs=
-github.com/opentracing/opentracing-go v1.2.0/go.mod h1:GxEUsuufX4nBwe+T+Wl9TAgYrxe9dPLANfrWvHYVTgc=
 github.com/paulbellamy/ratecounter v0.2.0/go.mod h1:Hfx1hDpSGoqxkVVpBi/IlYD7kChlfo5C6hzIHwPqfFE=
 github.com/pelletier/go-toml v1.9.5 h1:4yBQzkHv+7BHq2PQUZF3Mx0IYxG7LsP222s7Agd3ve8=
 github.com/pelletier/go-toml v1.9.5/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
@@ -420,7 +411,6 @@ github.com/prometheus/procfs v0.7.3/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1
 github.com/prometheus/procfs v0.8.0 h1:ODq8ZFEaYeCaZOJlZZdJA2AbQR98dSHSM1KW/You5mo=
 github.com/prometheus/procfs v0.8.0/go.mod h1:z7EfXMXOkbkqb9IINtpCn86r/to3BnA0uaxHdg830/4=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
-github.com/regen-network/protobuf v1.3.3-alpha.regen.1 h1:OHEc+q5iIAXpqiqFKeLpu5NwTIkVXUs48vFMwzqpqY4=
 github.com/regen-network/protobuf v1.3.3-alpha.regen.1/go.mod h1:2DjTFR1HhMQhiWC5sZ4OhQ3+NtdbZ6oBDKQwq5Ou+FI=
 github.com/retailnext/hllpp v1.0.1-0.20180308014038-101a6d2f8b52/go.mod h1:RDpi1RftBQPUCDRw6SmxeaREsAaRKnOclghuzp/WRzc=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
@@ -482,7 +472,6 @@ github.com/urfave/cli/v2 v2.3.0/go.mod h1:LJmUH05zAU44vOAcrfzZQKsZbVcdbOG8rtL3/X
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasthttp v1.38.0/go.mod h1:t/G+3rLek+CyY9bnIE+YlMRddxVAAGjhxndDB4i4C0I=
-github.com/valyala/fasthttp v1.40.0 h1:CRq/00MfruPGFLTQKY8b+8SfdK60TxNztjRMnH0t1Yc=
 github.com/valyala/fasthttp v1.40.0/go.mod h1:t/G+3rLek+CyY9bnIE+YlMRddxVAAGjhxndDB4i4C0I=
 github.com/valyala/fasthttp v1.41.0 h1:zeR0Z1my1wDHTRiamBCXVglQdbUwgb9uWG3k1HQz6jY=
 github.com/valyala/fasthttp v1.41.0/go.mod h1:f6VbjjoI3z1NDOZOv17o6RvtRSWxC77seBFc2uWtgiY=
@@ -512,19 +501,16 @@ go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.5/go.mod h1:5pWMHQbX5EPX2/62yrJeAkowc+lfs/XD7Uxpq3pI6kk=
 go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
-go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/atomic v1.10.0 h1:9qC72Qh0+3MqyJbAn8YU5xVq1frD8bn3JtD2oXtafVQ=
 go.uber.org/atomic v1.10.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/goleak v1.1.11-0.20210813005559-691160354723/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
+go.uber.org/goleak v1.1.11 h1:wy28qYRKZgnJTxGxvye5/wgWr1EKjmUDGYox5mGlRlI=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
-go.uber.org/multierr v1.5.0/go.mod h1:FeouvMocqHpRaaGuG9EjoKcStLC43Zu/fmqdUMPcKYU=
 go.uber.org/multierr v1.6.0/go.mod h1:cdWPpRnG4AhwMwsgIHip0KRBQjJy5kYEpYjJxpXp9iU=
 go.uber.org/multierr v1.8.0 h1:dg6GjLku4EH+249NNmoIciG9N/jURbDG+pFlTkhzIC8=
 go.uber.org/multierr v1.8.0/go.mod h1:7EAYxJLBy9rStEaz58O2t4Uvip6FSURkq8/ppBp95ak=
-go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee/go.mod h1:vJERXedbb3MVM5f9Ejo0C68/HhF8uaILCdgjnY+goOA=
 go.uber.org/zap v1.9.1/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
-go.uber.org/zap v1.16.0/go.mod h1:MA8QOfq0BHJwdXa996Y4dYkAqRKB8/1K1QMMZVaNZjQ=
 go.uber.org/zap v1.19.1/go.mod h1:j3DNczoxDZroyBnOT1L/Q79cfUMGZxlv/9dzN7SM1rI=
 go.uber.org/zap v1.22.0 h1:Zcye5DUgBloQ9BaT4qc9BnjOFog5TvBSAGkJ3Nf70c0=
 go.uber.org/zap v1.22.0/go.mod h1:H4siCOZOrAolnUPJEkfaSjDqyP+BDS0DdDWzwcgt3+U=
@@ -709,7 +695,6 @@ golang.org/x/sys v0.0.0-20220114195835-da31bd327af9/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220227234510-4e6760a101f9/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220412211240-33da011f77ad/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab h1:2QkjZIsXupsJbJIdSjjUOgWK3aEtzyuh2mPt3l/CkeU=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
 golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -746,8 +731,6 @@ golang.org/x/tools v0.0.0-20190628153133-6cdbf07be9d0/go.mod h1:/rFqwRUd4F7ZHNgw
 golang.org/x/tools v0.0.0-20190816200558-6889da9d5479/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20190911174233-4f2ddba30aff/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191012152004-8de300cfc20a/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20191029041327-9cc4af7d6b2c/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20191029190741-b9c20aec41a5/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191113191852-77e3bb0ad9e7/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191115202509-3a792d9c32b2/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
@@ -891,7 +874,6 @@ google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175
 google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

api/handlers/governor/controller.go

@@ -1,23 +1,26 @@
+// Package governor handle the request of governor data from governor endpoint defined in the api.
 package governor
 
 import (
 	"github.com/gofiber/fiber/v2"
 	"github.com/wormhole-foundation/wormhole-explorer/api/middleware"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
 	"go.uber.org/zap"
 )
 
+// Controller definition.
 type Controller struct {
 	srv    *Service
 	logger *zap.Logger
 }
 
+// NewController create a new controler.
 func NewController(serv *Service, logger *zap.Logger) *Controller {
 	return &Controller{srv: serv, logger: logger.With(zap.String("module", "GovernorController"))}
 }
 
+// FindGovernorConfigurations handler for the endpoint /governor/config/
 func (c *Controller) FindGovernorConfigurations(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	governorConfigs, err := c.srv.FindGovernorConfig(ctx.Context(), p)
 	if err != nil {
 		return err
@@ -25,9 +28,10 @@ func (c *Controller) FindGovernorConfigurations(ctx *fiber.Ctx) error {
 	return ctx.JSON(governorConfigs)
 }
 
+// FindGovernorConfigurationByGuardianAddress handler for the endpoint /governor/config/:guardian_address.
 func (c *Controller) FindGovernorConfigurationByGuardianAddress(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	guardianAddress, err := middleware.ExtractGuardianAddress(ctx)
+	guardianAddress, err := middleware.ExtractGuardianAddress(ctx, c.logger)
 	if err != nil {
 		return err
 	}
@@ -38,8 +42,9 @@ func (c *Controller) FindGovernorConfigurationByGuardianAddress(ctx *fiber.Ctx)
 	return ctx.JSON(govConfig)
 }
 
+// FindGovernorStatus handler for the endpoint /governor/status/.
 func (c *Controller) FindGovernorStatus(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	governorStatus, err := c.srv.FindGovernorStatus(ctx.Context(), p)
 	if err != nil {
 		return err
@@ -47,9 +52,10 @@ func (c *Controller) FindGovernorStatus(ctx *fiber.Ctx) error {
 	return ctx.JSON(governorStatus)
 }
 
+// FindGovernorStatusByGuardianAddress handler for the endpoint /governor/status/:guardian_address.
 func (c *Controller) FindGovernorStatusByGuardianAddress(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	guardianAddress, err := middleware.ExtractGuardianAddress(ctx)
+	guardianAddress, err := middleware.ExtractGuardianAddress(ctx, c.logger)
 	if err != nil {
 		return err
 	}
@@ -60,8 +66,9 @@ func (c *Controller) FindGovernorStatusByGuardianAddress(ctx *fiber.Ctx) error {
 	return ctx.JSON(govStatus)
 }
 
+// GetGovernorLimit handler for the endpoint /governor/limit/
 func (c *Controller) GetGovernorLimit(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	governorLimit, err := c.srv.GetGovernorLimit(ctx.Context(), p)
 	if err != nil {
 		return err
@@ -69,8 +76,9 @@ func (c *Controller) GetGovernorLimit(ctx *fiber.Ctx) error {
 	return ctx.JSON(governorLimit)
 }
 
+// FindNotionalLimit handler for the endpoint governor/notional/limit/
 func (c *Controller) FindNotionalLimit(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	notionalLimit, err := c.srv.FindNotionalLimit(ctx.Context(), p)
 	if err != nil {
 		return err
@@ -78,9 +86,10 @@ func (c *Controller) FindNotionalLimit(ctx *fiber.Ctx) error {
 	return ctx.JSON(notionalLimit)
 }
 
+// GetNotionalLimitByChainID handler for the endpoint governor/notional/limit/:chain.
 func (c *Controller) GetNotionalLimitByChainID(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, err := middleware.ExtractChainID(ctx)
+	chainID, err := middleware.ExtractChainID(ctx, c.logger)
 	if err != nil {
 		return err
 	}
@@ -91,8 +100,9 @@ func (c *Controller) GetNotionalLimitByChainID(ctx *fiber.Ctx) error {
 	return ctx.JSON(notionalLimit)
 }
 
+// GetAvailableNotional handler for the endpoint governor/notional/available/
 func (c *Controller) GetAvailableNotional(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	notionalAvaialabilies, err := c.srv.GetAvailableNotional(ctx.Context(), p)
 	if err != nil {
 		return err
@@ -100,9 +110,10 @@ func (c *Controller) GetAvailableNotional(ctx *fiber.Ctx) error {
 	return ctx.JSON(notionalAvaialabilies)
 }
 
+// GetAvailableNotionalByChainID handler for the endpoint governor/notional/available/:chain
 func (c *Controller) GetAvailableNotionalByChainID(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, err := middleware.ExtractChainID(ctx)
+	chainID, err := middleware.ExtractChainID(ctx, c.logger)
 	if err != nil {
 		return err
 	}
@@ -113,9 +124,10 @@ func (c *Controller) GetAvailableNotionalByChainID(ctx *fiber.Ctx) error {
 	return ctx.JSON(response)
 }
 
+// GetMaxNotionalAvailableByChainID handler for the endpoint governor/max_available/:chain.
 func (c *Controller) GetMaxNotionalAvailableByChainID(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, err := middleware.ExtractChainID(ctx)
+	chainID, err := middleware.ExtractChainID(ctx, c.logger)
 	if err != nil {
 		return err
 	}
@@ -126,8 +138,9 @@ func (c *Controller) GetMaxNotionalAvailableByChainID(ctx *fiber.Ctx) error {
 	return ctx.JSON(response)
 }
 
+// GetEnqueueVass handler for the endpoint governor/enqueued_vaas/
 func (c *Controller) GetEnqueueVass(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	enqueuedVaas, err := c.srv.GetEnqueueVass(ctx.Context(), p)
 	if err != nil {
 		return err
@@ -135,9 +148,10 @@ func (c *Controller) GetEnqueueVass(ctx *fiber.Ctx) error {
 	return ctx.JSON(enqueuedVaas)
 }
 
+// GetEnqueueVassByChainID handler for the endpoint governor/enqueued_vaas/:chain.
 func (c *Controller) GetEnqueueVassByChainID(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, err := middleware.ExtractChainID(ctx)
+	chainID, err := middleware.ExtractChainID(ctx, c.logger)
 	if err != nil {
 		return err
 	}

api/handlers/governor/model.go

@@ -1,3 +1,4 @@
+// Package governor handle the request of governor data from governor endpoint defined in the api.
 package governor
 
 import (
@@ -6,7 +7,7 @@ import (
 	"github.com/certusone/wormhole/node/pkg/vaa"
 )
 
-// GovConfigPage definition.
+// GovConfigPage represent a governor configuration.
 type GovConfig struct {
 	ID        string              `bson:"_id" json:"id"`
 	CreatedAt *time.Time          `bson:"createdAt" json:"createdAt"`
@@ -29,7 +30,7 @@ type GovConfigfTokens struct {
 	Price         float64 `bson:"price" json:"price"`
 }
 
-// GovStatusPage definition.
+// GovStatusPage represent a governor status.
 type GovStatus struct {
 	ID        string             `bson:"_id" json:"id"`
 	CreatedAt *time.Time         `bson:"createdAt" json:"createdAt"`
@@ -50,17 +51,17 @@ type GovStatusChainEmitter struct {
 	EnqueuedVass      interface{} `bson:"enqueuedvaas" json:"enqueuedvaas"`
 }
 
-// NotionalLimit definition.
+// NotionalLimit represent the notional limit value and maximun tranasction size for a chainID.
 type NotionalLimit struct {
 	ChainID           vaa.ChainID `bson:"chainid" json:"chainid"`
 	NotionalLimit     *int64      `bson:"notionalLimit" json:"notionalLimit"`
 	MaxTrasactionSize *int64      `bson:"maxTransactionSize" json:"maxTransactionSize"`
 }
 
-// NotionalLimitDetail definition.
+// NotionalLimitDetail represent a notional limit value
 type NotionalLimitDetail struct {
 	ID                string      `bson:"_id" json:"id"`
-	ChainID           vaa.ChainID `bson:"chainid" json:"chainid"`
+	ChainID           vaa.ChainID `bson:"chainId" json:"chainId"`
 	NodeName          string      `bson:"nodename" json:"nodename"`
 	NotionalLimit     *int64      `bson:"notionalLimit" json:"notionalLimit"`
 	MaxTrasactionSize *int64      `bson:"maxTransactionSize" json:"maxTransactionSize"`
@@ -68,11 +69,13 @@ type NotionalLimitDetail struct {
 	UpdatedAt         *time.Time  `bson:"updatedAt" json:"updatedAt"`
 }
 
+// NotionalAvailable represent the available notional for chainID.
 type NotionalAvailable struct {
 	ChainID           vaa.ChainID `bson:"chainid" json:"chainId"`
 	AvailableNotional *int64      `bson:"availableNotional" json:"availableNotional"`
 }
 
+// NotionalAvailableDetail represent a notional available value.
 type NotionalAvailableDetail struct {
 	ID                string      `bson:"_id" json:"id"`
 	ChainID           vaa.ChainID `bson:"chainId" json:"chainId"`
@@ -108,6 +111,7 @@ type EnqueuedVaa struct {
 	TxHash         string      `bson:"txHash" json:"txHash"`
 }
 
+// EnqueuedVaas definition.
 type EnqueuedVaas struct {
 	ChainID     vaa.ChainID    `bson:"chainid" json:"chainId"`
 	EnqueuedVaa []*EnqueuedVaa `bson:"enqueuedVaas" json:"enqueuedVaas"`

api/handlers/governor/repository.go

@@ -1,14 +1,16 @@
+// Package governor handle the request of governor data from governor endpoint defined in the api.
 package governor
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"sort"
 	"time"
 
 	"github.com/certusone/wormhole/node/pkg/vaa"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
+	"github.com/pkg/errors"
+	errs "github.com/wormhole-foundation/wormhole-explorer/api/internal/errors"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/pagination"
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
@@ -17,10 +19,7 @@ import (
 
 const minGuardianNum = 13
 
-var (
+// Repository definition.
-	ErrWrongQuery = errors.New("MALFORMED_QUERY")
-)
-
 type Repository struct {
 	db          *mongo.Database
 	logger      *zap.Logger
@@ -30,6 +29,7 @@ type Repository struct {
 	}
 }
 
+// NewRepository create a new Repository.
 func NewRepository(db *mongo.Database, logger *zap.Logger) *Repository {
 	return &Repository{db: db,
 		logger: logger.With(zap.String("module", "GovernorRepository")),
@@ -43,21 +43,25 @@ func NewRepository(db *mongo.Database, logger *zap.Logger) *Repository {
 	}
 }
 
+// GovernorQuery respresent a query for the governors mongodb documents.
 type GovernorQuery struct {
 	pagination.Pagination
 	id string
 }
 
+// QueryGovernor create a new GovernorQuery with default pagination values.
 func QueryGovernor() *GovernorQuery {
 	page := pagination.FirstPage()
 	return &GovernorQuery{Pagination: *page}
 }
 
+// SetID set the id field of the GovernorQuery struct.
 func (q *GovernorQuery) SetID(id string) *GovernorQuery {
 	q.id = id
 	return q
 }
 
+// SetPagination set the pagination field of the GovernorQuery struct.
 func (q *GovernorQuery) SetPagination(p *pagination.Pagination) *GovernorQuery {
 	q.Pagination = *p
 	return q
@@ -71,6 +75,7 @@ func (q *GovernorQuery) toBSON() *bson.D {
 	return &r
 }
 
+// FindGovConfigurations get a list of *GovConfig.
 func (r *Repository) FindGovConfigurations(ctx context.Context, q *GovernorQuery) ([]*GovConfig, error) {
 	if q == nil {
 		q = QueryGovernor()
@@ -87,19 +92,26 @@ func (r *Repository) FindGovConfigurations(ctx context.Context, q *GovernorQuery
 	options := options.Find().SetProjection(projection).SetLimit(q.PageSize).SetSkip(q.Offset).SetSort(sort)
 	cur, err := r.collections.governorConfig.Find(ctx, q.toBSON(), options)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Find command to get governor configurations",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	var govConfigs []*GovConfig
 	err = cur.All(ctx, &govConfigs)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*GovConfig", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	return govConfigs, err
 }
 
+// FindGovConfiguration get a *GovConfig. The q parameter define the filter to apply to the query.
 func (r *Repository) FindGovConfiguration(ctx context.Context, q *GovernorQuery) (*GovConfig, error) {
 	if q == nil {
-		return nil, ErrWrongQuery
+		return nil, errs.ErrMalformedQuery
 	}
 	var govConfig GovConfig
 	projection := bson.D{
@@ -113,11 +125,18 @@ func (r *Repository) FindGovConfiguration(ctx context.Context, q *GovernorQuery)
 	options := options.FindOne().SetProjection(projection)
 	err := r.collections.governorConfig.FindOne(ctx, q.toBSON(), options).Decode(&govConfig)
 	if err != nil {
-		return nil, err
+		if errors.Is(err, mongo.ErrNoDocuments) {
+			return nil, errs.ErrNotFound
+		}
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute FindOne command to get governor configuration",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	return &govConfig, err
 }
 
+// FindGovernorStatus get a list of *GovStatus.
 func (r *Repository) FindGovernorStatus(ctx context.Context, q *GovernorQuery) ([]*GovStatus, error) {
 	if q == nil {
 		q = QueryGovernor()
@@ -132,19 +151,26 @@ func (r *Repository) FindGovernorStatus(ctx context.Context, q *GovernorQuery) (
 	options := options.Find().SetProjection(projection).SetLimit(q.PageSize).SetSkip(q.Offset).SetSort(sort)
 	cur, err := r.collections.governorStatus.Find(ctx, q.toBSON(), options)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Find command to get all governor status",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	var govStatus []*GovStatus
 	err = cur.All(ctx, &govStatus)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*GovStatus", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	return govStatus, err
 }
 
+// FindOneGovernorStatus get a *GovStatus. The q parameter define the filter to apply to the query.
 func (r *Repository) FindOneGovernorStatus(ctx context.Context, q *GovernorQuery) (*GovStatus, error) {
 	if q == nil {
-		return nil, ErrWrongQuery
+		return nil, errs.ErrMalformedQuery
 	}
 	var govConfig GovStatus
 	projection := bson.D{
@@ -156,37 +182,49 @@ func (r *Repository) FindOneGovernorStatus(ctx context.Context, q *GovernorQuery
 	options := options.FindOne().SetProjection(projection)
 	err := r.collections.governorStatus.FindOne(ctx, q.toBSON(), options).Decode(&govConfig)
 	if err != nil {
-		return nil, err
+		if errors.Is(err, mongo.ErrNoDocuments) {
+			return nil, errs.ErrNotFound
+		}
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute FindOne command to get governor status",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	return &govConfig, err
 }
 
+// NotionalLimitQuery
 type NotionalLimitQuery struct {
 	pagination.Pagination
 	id      string
 	chainID vaa.ChainID
 }
 
+// QueryNotionalLimit create a new NotionalLimitQuery with default pagination values.
 func QueryNotionalLimit() *NotionalLimitQuery {
 	page := pagination.FirstPage()
 	return &NotionalLimitQuery{Pagination: *page}
 }
 
+// SetID set the id field of the NotionalLimitQuery struct.
 func (q *NotionalLimitQuery) SetID(id string) *NotionalLimitQuery {
 	q.id = id
 	return q
 }
 
+// SetChain set the chainID field of the NotionalLimitQuery struct.
 func (q *NotionalLimitQuery) SetChain(chainID vaa.ChainID) *NotionalLimitQuery {
 	q.chainID = chainID
 	return q
 }
 
+// SetPagination set the Pagination field of the NotionalLimitQuery struct.
 func (q *NotionalLimitQuery) SetPagination(p *pagination.Pagination) *NotionalLimitQuery {
 	q.Pagination = *p
 	return q
 }
 
+// FindNotionalLimit get a list *NotionalLimit.
 func (r *Repository) FindNotionalLimit(ctx context.Context, q *NotionalLimitQuery) ([]*NotionalLimit, error) {
 	// agreggation stages to get notionalLimit for each chainID.
 	matchStage1 := bson.D{{Key: "$match", Value: bson.D{}}}
@@ -259,24 +297,31 @@ func (r *Repository) FindNotionalLimit(ctx context.Context, q *NotionalLimitQuer
 	// execute aggregate operations.
 	cur, err := r.collections.governorConfig.Aggregate(ctx, pipeLine)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get notional limit",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// decodes to NotionalLimit.
 	var notionalLimits []*NotionalLimit
 	err = cur.All(ctx, &notionalLimits)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*NotionalLimit", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// check records exists.
 	if len(notionalLimits) == 0 {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	return notionalLimits, nil
 }
 
+// GetNotionalLimitByChainID get a list *NotionalLimitDetail.
 func (r *Repository) GetNotionalLimitByChainID(ctx context.Context, q *NotionalLimitQuery) ([]*NotionalLimitDetail, error) {
 	// agreggation stages to get notionalLimit by chainID.
 	matchStage1 := bson.D{{Key: "$match", Value: bson.D{}}}
@@ -333,19 +378,26 @@ func (r *Repository) GetNotionalLimitByChainID(ctx context.Context, q *NotionalL
 	// execute aggregate operations.
 	cur, err := r.collections.governorConfig.Aggregate(ctx, pipeLine)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get notional limit by chainID",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// decode to []NotionalLimitRecord.
 	var notionalLimits []*NotionalLimitDetail
 	err = cur.All(ctx, &notionalLimits)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*NotionalLimitDetail", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	return notionalLimits, nil
 }
 
+// GetAvailableNotional get a list of *NotionalAvailable.
 func (r *Repository) GetAvailableNotional(ctx context.Context, q *NotionalLimitQuery) ([]*NotionalAvailable, error) {
 	// stage.
 	matchStage1 := bson.D{{Key: "$match", Value: bson.D{}}}
@@ -421,24 +473,31 @@ func (r *Repository) GetAvailableNotional(ctx context.Context, q *NotionalLimitQ
 	// execute aggregate operations.
 	cur, err := r.collections.governorStatus.Aggregate(ctx, pipeLine)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get available notional",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// decode to []NotionalLimitRecord.
 	var notionalAvailables []*NotionalAvailable
 	err = cur.All(ctx, &notionalAvailables)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*NotionalAvailable", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// check exists records
 	if len(notionalAvailables) == 0 {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	return notionalAvailables, nil
 }
 
+// GetAvailableNotionalByChainID get a list of *NotionalAvailableDetail.
 func (r *Repository) GetAvailableNotionalByChainID(ctx context.Context, q *NotionalLimitQuery) ([]*NotionalAvailableDetail, error) {
 	// stage definitions.
 	matchStage1 := bson.D{{Key: "$match", Value: bson.D{}}}
@@ -497,19 +556,26 @@ func (r *Repository) GetAvailableNotionalByChainID(ctx context.Context, q *Notio
 	// execute aggregate operations.
 	cur, err := r.collections.governorStatus.Aggregate(ctx, pipeLine)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get available notional by chainID",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// decode to []NotionalLimitRecord.
 	var notionalAvailability []*NotionalAvailableDetail
 	err = cur.All(ctx, &notionalAvailability)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*NotionalAvailableDetail", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	return notionalAvailability, nil
 }
 
+// GetMaxNotionalAvailableByChainID get a *MaxNotionalAvailableRecord.
 func (r *Repository) GetMaxNotionalAvailableByChainID(ctx context.Context, q *NotionalLimitQuery) (*MaxNotionalAvailableRecord, error) {
 	// stage definitions.
 	matchStage1 := bson.D{{Key: "$match", Value: bson.D{}}}
@@ -577,55 +643,67 @@ func (r *Repository) GetMaxNotionalAvailableByChainID(ctx context.Context, q *No
 	// execute aggregate operations.
 	cur, err := r.collections.governorStatus.Aggregate(ctx, pipeLine)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get maximun available notional by chainID",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// decode to []NotionalLimitRecord.
 	var rows []*MaxNotionalAvailableRecord
 	err = cur.All(ctx, &rows)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*MaxNotionalAvailableRecord", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// check exists records
 	if len(rows) == 0 {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	if len(rows) < minGuardianNum {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	maxNotionalLimit := rows[minGuardianNum-1]
 	return maxNotionalLimit, nil
 }
 
+// EnqueuedVaaQuery respresent a query for enqueuedVaa queries.
 type EnqueuedVaaQuery struct {
 	pagination.Pagination
 	id      string
 	chainID vaa.ChainID
 }
 
+// QueryEnqueuedVaa create a new EnqueuedVaaQuery with default pagination values.
 func QueryEnqueuedVaa() *EnqueuedVaaQuery {
 	page := pagination.FirstPage()
 	return &EnqueuedVaaQuery{Pagination: *page}
 }
 
+// SetID set the id field of the EnqueuedVaaQuery struct.
 func (q *EnqueuedVaaQuery) SetID(id string) *EnqueuedVaaQuery {
 	q.id = id
 	return q
 }
 
+// SetChain set the chainID field of the EnqueuedVaaQuery struct.
 func (q *EnqueuedVaaQuery) SetChain(chainID vaa.ChainID) *EnqueuedVaaQuery {
 	q.chainID = chainID
 	return q
 }
 
+// SetPagination set the pagination field of the EnqueuedVaaQuery struct.
 func (q *EnqueuedVaaQuery) SetPagination(p *pagination.Pagination) *EnqueuedVaaQuery {
 	q.Pagination = *p
 	return q
 }
 
+// GetEnqueueVass get a list of *EnqueuedVaas.
 func (r *Repository) GetEnqueueVass(ctx context.Context, q *EnqueuedVaaQuery) ([]*EnqueuedVaas, error) {
 	// match stage.
 	matchStage1 := bson.D{{Key: "$match", Value: bson.D{}}}
@@ -678,7 +756,10 @@ func (r *Repository) GetEnqueueVass(ctx context.Context, q *EnqueuedVaaQuery) ([
 
 	cur, err := r.collections.governorStatus.Aggregate(ctx, pipeLine)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get enqueued vaas",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	var rows []struct {
@@ -697,11 +778,14 @@ func (r *Repository) GetEnqueueVass(ctx context.Context, q *EnqueuedVaaQuery) ([
 	// decode query response.
 	err = cur.All(ctx, &rows)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to rows", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	if len(rows) == 0 {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	// TODO: Change this logic to mongo query code.
@@ -732,7 +816,7 @@ func (r *Repository) GetEnqueueVass(ctx context.Context, q *EnqueuedVaaQuery) ([
 	}
 
 	if len(enqueuedVaas) == 0 {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	// group by chainID.
@@ -760,6 +844,7 @@ func (r *Repository) GetEnqueueVass(ctx context.Context, q *EnqueuedVaaQuery) ([
 	return response, nil
 }
 
+// GetEnqueueVassByChainID get a list of *EnqueuedVaaDetail by chainID.
 func (r *Repository) GetEnqueueVassByChainID(ctx context.Context, q *EnqueuedVaaQuery) ([]*EnqueuedVaaDetail, error) {
 	// stage definitions.
 	matchStage1 := bson.D{{Key: "$match", Value: bson.D{}}}
@@ -823,7 +908,10 @@ func (r *Repository) GetEnqueueVassByChainID(ctx context.Context, q *EnqueuedVaa
 
 	cur, err := r.collections.governorStatus.Aggregate(ctx, pipeline)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get enqueued vaas by chainID",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// decode query response.
@@ -840,7 +928,10 @@ func (r *Repository) GetEnqueueVassByChainID(ctx context.Context, q *EnqueuedVaa
 	}
 	err = cur.All(ctx, &rows)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to rows", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// TODO: Change this logic to mongo query code.
@@ -871,7 +962,7 @@ func (r *Repository) GetEnqueueVassByChainID(ctx context.Context, q *EnqueuedVaa
 	}
 
 	if len(response) == 0 {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	// sort response by sequence.
@@ -881,6 +972,7 @@ func (r *Repository) GetEnqueueVassByChainID(ctx context.Context, q *EnqueuedVaa
 	return response, nil
 }
 
+// GetGovernorLimit get a list of *GovernorLimit.
 func (r *Repository) GetGovernorLimit(ctx context.Context, q *GovernorQuery) ([]*GovernorLimit, error) {
 	// lookup.
 	lookupStage1 := bson.D{
@@ -1017,19 +1109,25 @@ func (r *Repository) GetGovernorLimit(ctx context.Context, q *GovernorQuery) ([]
 	// execute aggregate operations.
 	cur, err := r.collections.governorConfig.Aggregate(ctx, pipeLine)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get governor limit",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// decodes to RawDocRecord.
 	var governorLimits []*GovernorLimit
 	err = cur.All(ctx, &governorLimits)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*GovernorLimit", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 
 	// check exists records
 	if len(governorLimits) == 0 {
-		return nil, errors.New("not found")
+		return nil, errs.ErrNotFound
 	}
 
 	return governorLimits, nil

api/handlers/governor/service.go

@@ -1,11 +1,12 @@
+// Package governor handle the request of governor data from governor endpoint defined in the api.
 package governor
 
 import (
 	"context"
 
 	"github.com/certusone/wormhole/node/pkg/vaa"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/pagination"
-	"github.com/wormhole-foundation/wormhole-explorer/api/services"
+	"github.com/wormhole-foundation/wormhole-explorer/api/response"
 	"go.uber.org/zap"
 )
 
@@ -20,118 +21,118 @@ func NewService(dao *Repository, logger *zap.Logger) *Service {
 }
 
 // FindGovernorConfig get a list of governor configurations.
-func (s *Service) FindGovernorConfig(ctx context.Context, p *pagination.Pagination) (*services.Response[[]*GovConfig], error) {
+func (s *Service) FindGovernorConfig(ctx context.Context, p *pagination.Pagination) (*response.Response[[]*GovConfig], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 	query := QueryGovernor().SetPagination(p)
 	govConfigs, err := s.repo.FindGovConfigurations(ctx, query)
-	res := services.Response[[]*GovConfig]{Data: govConfigs, Error: err}
+	res := response.Response[[]*GovConfig]{Data: govConfigs}
 	return &res, err
 }
 
 // FindGovernorConfigByGuardianAddress get a governor configuration by guardianAddress.
-func (s *Service) FindGovernorConfigByGuardianAddress(ctx context.Context, guardianAddress string, p *pagination.Pagination) (*services.Response[*GovConfig], error) {
+func (s *Service) FindGovernorConfigByGuardianAddress(ctx context.Context, guardianAddress string, p *pagination.Pagination) (*response.Response[*GovConfig], error) {
 	query := QueryGovernor().SetID(guardianAddress).SetPagination(p)
 	govConfig, err := s.repo.FindGovConfiguration(ctx, query)
-	res := services.Response[*GovConfig]{Data: govConfig, Error: err}
+	res := response.Response[*GovConfig]{Data: govConfig}
 	return &res, err
 }
 
 // FindGovernorStatus get a list of governor status.
-func (s *Service) FindGovernorStatus(ctx context.Context, p *pagination.Pagination) (*services.Response[[]*GovStatus], error) {
+func (s *Service) FindGovernorStatus(ctx context.Context, p *pagination.Pagination) (*response.Response[[]*GovStatus], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 	query := QueryGovernor().SetPagination(p)
 	govStatus, err := s.repo.FindGovernorStatus(ctx, query)
-	res := services.Response[[]*GovStatus]{Data: govStatus, Error: err}
+	res := response.Response[[]*GovStatus]{Data: govStatus}
 	return &res, err
 }
 
 // FindGovernorStatusByGuardianAddress get a governor status by guardianAddress.
-func (s *Service) FindGovernorStatusByGuardianAddress(ctx context.Context, guardianAddress string, p *pagination.Pagination) (*services.Response[*GovStatus], error) {
+func (s *Service) FindGovernorStatusByGuardianAddress(ctx context.Context, guardianAddress string, p *pagination.Pagination) (*response.Response[*GovStatus], error) {
 	query := QueryGovernor().SetID(guardianAddress).SetPagination(p)
 	govStatus, err := s.repo.FindOneGovernorStatus(ctx, query)
-	res := services.Response[*GovStatus]{Data: govStatus, Error: err}
+	res := response.Response[*GovStatus]{Data: govStatus}
 	return &res, err
 }
 
 // FindNotionalLimit get a notional limit for each chainID.
-func (s *Service) FindNotionalLimit(ctx context.Context, p *pagination.Pagination) (*services.Response[[]*NotionalLimit], error) {
+func (s *Service) FindNotionalLimit(ctx context.Context, p *pagination.Pagination) (*response.Response[[]*NotionalLimit], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 	query := QueryNotionalLimit().SetPagination(p)
 	notionalLimit, err := s.repo.FindNotionalLimit(ctx, query)
-	res := services.Response[[]*NotionalLimit]{Data: notionalLimit, Error: err}
+	res := response.Response[[]*NotionalLimit]{Data: notionalLimit}
 	return &res, err
 }
 
 // GetNotionalLimitByChainID get a notional limit by chainID.
-func (s *Service) GetNotionalLimitByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*services.Response[[]*NotionalLimitDetail], error) {
+func (s *Service) GetNotionalLimitByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*response.Response[[]*NotionalLimitDetail], error) {
 	query := QueryNotionalLimit().SetPagination(p).SetChain(chainID)
 	notionalLimit, err := s.repo.GetNotionalLimitByChainID(ctx, query)
-	res := services.Response[[]*NotionalLimitDetail]{Data: notionalLimit, Error: err}
+	res := response.Response[[]*NotionalLimitDetail]{Data: notionalLimit}
 	return &res, err
 }
 
 // GetAvailableNotional get a available notional for each chainID.
-func (s *Service) GetAvailableNotional(ctx context.Context, p *pagination.Pagination) (*services.Response[[]*NotionalAvailable], error) {
+func (s *Service) GetAvailableNotional(ctx context.Context, p *pagination.Pagination) (*response.Response[[]*NotionalAvailable], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 	query := QueryNotionalLimit().SetPagination(p)
 	notionalAvailability, err := s.repo.GetAvailableNotional(ctx, query)
-	res := services.Response[[]*NotionalAvailable]{Data: notionalAvailability, Error: err}
+	res := response.Response[[]*NotionalAvailable]{Data: notionalAvailability}
 	return &res, err
 }
 
 // GetAvailableNotionalByChainID get a available notional by chainID.
-func (s *Service) GetAvailableNotionalByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*services.Response[[]*NotionalAvailableDetail], error) {
+func (s *Service) GetAvailableNotionalByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*response.Response[[]*NotionalAvailableDetail], error) {
 	query := QueryNotionalLimit().SetPagination(p).SetChain(chainID)
 	notionaLAvailability, err := s.repo.GetAvailableNotionalByChainID(ctx, query)
-	res := services.Response[[]*NotionalAvailableDetail]{Data: notionaLAvailability, Error: err}
+	res := response.Response[[]*NotionalAvailableDetail]{Data: notionaLAvailability}
 	return &res, err
 }
 
 // GetMaxNotionalAvailableByChainID get a maximun notional value by chainID.
-func (s *Service) GetMaxNotionalAvailableByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*services.Response[*MaxNotionalAvailableRecord], error) {
+func (s *Service) GetMaxNotionalAvailableByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*response.Response[*MaxNotionalAvailableRecord], error) {
 	query := QueryNotionalLimit().SetPagination(p).SetChain(chainID)
 	maxNotionaLAvailable, err := s.repo.GetMaxNotionalAvailableByChainID(ctx, query)
-	res := services.Response[*MaxNotionalAvailableRecord]{Data: maxNotionaLAvailable, Error: err}
+	res := response.Response[*MaxNotionalAvailableRecord]{Data: maxNotionaLAvailable}
 	return &res, err
 }
 
-// GetEnqueueVass.
+// GetEnqueueVaas get all the enqueued vaa.
-func (s *Service) GetEnqueueVass(ctx context.Context, p *pagination.Pagination) (*services.Response[[]*EnqueuedVaas], error) {
+func (s *Service) GetEnqueueVass(ctx context.Context, p *pagination.Pagination) (*response.Response[[]*EnqueuedVaas], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 	query := QueryEnqueuedVaa().SetPagination(p)
 	enqueuedVaaResponse, err := s.repo.GetEnqueueVass(ctx, query)
-	res := services.Response[[]*EnqueuedVaas]{Data: enqueuedVaaResponse, Error: err}
+	res := response.Response[[]*EnqueuedVaas]{Data: enqueuedVaaResponse}
 	return &res, err
 }
 
-// GetEnqueueVassByChainID by chainID.
+// GetEnqueueVassByChainID get enequeued vaa by chainID.
-func (s *Service) GetEnqueueVassByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*services.Response[[]*EnqueuedVaaDetail], error) {
+func (s *Service) GetEnqueueVassByChainID(ctx context.Context, p *pagination.Pagination, chainID vaa.ChainID) (*response.Response[[]*EnqueuedVaaDetail], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 	query := QueryEnqueuedVaa().SetPagination(p).SetChain(chainID)
 	enqueuedVaaRecord, err := s.repo.GetEnqueueVassByChainID(ctx, query)
-	res := services.Response[[]*EnqueuedVaaDetail]{Data: enqueuedVaaRecord, Error: err}
+	res := response.Response[[]*EnqueuedVaaDetail]{Data: enqueuedVaaRecord}
 	return &res, err
 }
 
 // GetGovernorLimit get governor limit.
-func (s *Service) GetGovernorLimit(ctx context.Context, p *pagination.Pagination) (*services.Response[[]*GovernorLimit], error) {
+func (s *Service) GetGovernorLimit(ctx context.Context, p *pagination.Pagination) (*response.Response[[]*GovernorLimit], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 	query := QueryGovernor().SetPagination(p)
 	governorLimit, err := s.repo.GetGovernorLimit(ctx, query)
-	res := services.Response[[]*GovernorLimit]{Data: governorLimit, Error: err}
+	res := response.Response[[]*GovernorLimit]{Data: governorLimit}
 	return &res, err
 }

api/handlers/observations/controller.go

@@ -1,19 +1,19 @@
+// Package observations handle the request of observations data from governor endpoint defined in the api.
 package observations
 
 import (
-	"github.com/certusone/wormhole/node/pkg/vaa"
 	"github.com/gofiber/fiber/v2"
-	"github.com/wormhole-foundation/wormhole-explorer/api/errors"
 	"github.com/wormhole-foundation/wormhole-explorer/api/middleware"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
 	"go.uber.org/zap"
 )
 
+// Controller definition.
 type Controller struct {
 	srv    *Service
 	logger *zap.Logger
 }
 
+// NewController create a new controler.
 func NewController(srv *Service, logger *zap.Logger) *Controller {
 	return &Controller{
 		srv:    srv,
@@ -21,8 +21,9 @@ func NewController(srv *Service, logger *zap.Logger) *Controller {
 	}
 }
 
+// FindAll handler for the endpoint /observations/.
 func (c *Controller) FindAll(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	obs, err := c.srv.FindAll(ctx.Context(), p)
 	if err != nil {
 		return err
@@ -30,9 +31,13 @@ func (c *Controller) FindAll(ctx *fiber.Ctx) error {
 	return ctx.JSON(obs)
 }
 
+// FindAllByChain handler for the endpoint /observations/:chain.
 func (c *Controller) FindAllByChain(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, err := middleware.ExtractChainID(ctx)
+	chainID, err := middleware.ExtractChainID(ctx, c.logger)
+	if err != nil {
+		return err
+	}
 	obs, err := c.srv.FindByChain(ctx.Context(), chainID, p)
 	if err != nil {
 		return err
@@ -40,12 +45,14 @@ func (c *Controller) FindAllByChain(ctx *fiber.Ctx) error {
 	return ctx.JSON(obs)
 }
 
+// FindAllByEmitter handler for the endpoint /observations/:chain/:emitter.
 func (c *Controller) FindAllByEmitter(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, addr, _, err := middleware.ExtractVAAParams(ctx)
+	chainID, addr, err := middleware.ExtractVAAChainIDEmitter(ctx, c.logger)
-	if errors.IsOf(err, middleware.ErrMalformedChain, middleware.ErrMalformedAddr) {
+	if err != nil {
 		return err
 	}
+
 	obs, err := c.srv.FindByEmitter(ctx.Context(), chainID, addr, p)
 	if err != nil {
 		return err
@@ -53,9 +60,10 @@ func (c *Controller) FindAllByEmitter(ctx *fiber.Ctx) error {
 	return ctx.JSON(obs)
 }
 
+// FindAllByVAA handler for the endpoint  /observations/:chain/:emitter/:sequence
 func (c *Controller) FindAllByVAA(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, addr, seq, err := middleware.ExtractVAAParams(ctx)
+	chainID, addr, seq, err := middleware.ExtractVAAParams(ctx, c.logger)
 	if err != nil {
 		return err
 	}
@@ -66,18 +74,21 @@ func (c *Controller) FindAllByVAA(ctx *fiber.Ctx) error {
 	return ctx.JSON(obs)
 }
 
+// FindOne handler for the endpoint /observations/:chain/:emitter/:sequence/:signer/:hash
 func (c *Controller) FindOne(ctx *fiber.Ctx) error {
-	chainID, addr, seq, err := middleware.ExtractVAAParams(ctx)
+	chainID, addr, seq, err := middleware.ExtractVAAParams(ctx, c.logger)
 	if err != nil {
 		return err
 	}
-	signer := ctx.Params("signer")
+	signerAddr, err := middleware.ExtractObservationSigner(ctx, c.logger)
-	signerAddr, err := vaa.StringToAddress(signer)
 	if err != nil {
 		return err
 	}
-	hash := ctx.Params("hash")
+	hash, err := middleware.ExtractObservationHash(ctx, c.logger)
-	obs, err := c.srv.FindOne(ctx.Context(), chainID, addr, seq, &signerAddr, []byte(hash))
+	if err != nil {
+		return err
+	}
+	obs, err := c.srv.FindOne(ctx.Context(), chainID, addr, seq, signerAddr, []byte(hash))
 	if err != nil {
 		return err
 	}

api/handlers/observations/model.go

@@ -1,10 +1,13 @@
+// Package observations handle the request of observations data from governor endpoint defined in the api.
 package observations
 
 import (
-	"github.com/certusone/wormhole/node/pkg/vaa"
 	"time"
+
+	"github.com/certusone/wormhole/node/pkg/vaa"
 )
 
+// ObservationDoc represent an observation document.
 type ObservationDoc struct {
 	ID           string      `bson:"_id" json:"id"`
 	Version      uint8       `bson:"version" json:"version"`
@@ -15,7 +18,6 @@ type ObservationDoc struct {
 	TxHash       []byte      `bson:"txHash" json:"txHash"`
 	GuardianAddr string      `bson:"guardianAddr" json:"guardianAddr"`
 	Signature    []byte      `bson:"signature" json:"signature"`
-
+	UpdatedAt    *time.Time  `bson:"updatedAt" json:"updatedAt"`
-	UpdatedAt *time.Time `bson:"updatedAt" json:"updatedAt"`
+	IndexedAt    *time.Time  `bson:"indexedAt" json:"indexedAt"`
-	IndexedAt *time.Time `bson:"indexedAt" json:"indexedAt"`
 }

api/handlers/observations/repository.go

@@ -1,16 +1,21 @@
+// Package observations handle the request of observations data from governor endpoint defined in the api.
 package observations
 
 import (
 	"context"
-	"errors"
+	"fmt"
+
 	"github.com/certusone/wormhole/node/pkg/vaa"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
+	"github.com/pkg/errors"
+	errs "github.com/wormhole-foundation/wormhole-explorer/api/internal/errors"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/pagination"
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
 	"go.uber.org/zap"
 )
 
+// Repository definition.
 type Repository struct {
 	db          *mongo.Database
 	logger      *zap.Logger
@@ -19,6 +24,7 @@ type Repository struct {
 	}
 }
 
+// NewRepository create a new Repository.
 func NewRepository(db *mongo.Database, logger *zap.Logger) *Repository {
 	return &Repository{db: db,
 		logger:      logger.With(zap.String("module", "ObservationsRepository")),
@@ -26,6 +32,8 @@ func NewRepository(db *mongo.Database, logger *zap.Logger) *Repository {
 	}
 }
 
+// Find get a list of ObservationDoc pointers.
+// The input parameter [q *ObservationQuery] define the filters to apply in the query.
 func (r *Repository) Find(ctx context.Context, q *ObservationQuery) ([]*ObservationDoc, error) {
 	if q == nil {
 		q = Query()
@@ -33,32 +41,43 @@ func (r *Repository) Find(ctx context.Context, q *ObservationQuery) ([]*Observat
 	sort := bson.D{{q.SortBy, q.GetSortInt()}}
 	cur, err := r.collections.observations.Find(ctx, q.toBSON(), options.Find().SetLimit(q.PageSize).SetSkip(q.Offset).SetSort(sort))
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Find command to get observations",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	var obs []*ObservationDoc
 	err = cur.All(ctx, &obs)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*ObservationDoc", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	return obs, err
 }
 
-var (
+// Find get ObservationDoc pointer.
-	ErrWrongQuery = errors.New("MALFORMED_QUERY")
+// The input parameter [q *ObservationQuery] define the filters to apply in the query.
-)
-
 func (r *Repository) FindOne(ctx context.Context, q *ObservationQuery) (*ObservationDoc, error) {
 	if q == nil {
-		return nil, ErrWrongQuery
+		return nil, errs.ErrMalformedQuery
 	}
 	var obs ObservationDoc
 	err := r.collections.observations.FindOne(ctx, q.toBSON()).Decode(&obs)
 	if err != nil {
-		return nil, err
+		if errors.Is(err, mongo.ErrNoDocuments) {
+			return nil, errs.ErrNotFound
+		}
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute FindOne command to get observations",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	return &obs, err
 }
 
+// ObservationQuery respresent a query for the observation mongodb document.
 type ObservationQuery struct {
 	pagination.Pagination
 	chainId      vaa.ChainID
@@ -69,36 +88,43 @@ type ObservationQuery struct {
 	uint64
 }
 
+// Query create a new ObservationQuery with default pagination vaues.
 func Query() *ObservationQuery {
 	page := pagination.FirstPage()
 	return &ObservationQuery{Pagination: *page}
 }
 
+// SetEmitter set the chainId field of the ObservationQuery struct.
 func (q *ObservationQuery) SetChain(chainID vaa.ChainID) *ObservationQuery {
 	q.chainId = chainID
 	return q
 }
 
+// SetEmitter set the emitter field of the ObservationQuery struct.
 func (q *ObservationQuery) SetEmitter(emitter string) *ObservationQuery {
 	q.emitter = emitter
 	return q
 }
 
+// SetSequence set the sequence field of the ObservationQuery struct.
 func (q *ObservationQuery) SetSequence(seq uint64) *ObservationQuery {
 	q.sequence = seq
 	return q
 }
 
+// SetGuardianAddr set the guardianAddr field of the ObservationQuery struct.
 func (q *ObservationQuery) SetGuardianAddr(guardianAddr string) *ObservationQuery {
 	q.guardianAddr = guardianAddr
 	return q
 }
 
+// SetHash set the hash field of the ObservationQuery struct.
 func (q *ObservationQuery) SetHash(hash []byte) *ObservationQuery {
 	q.hash = hash
 	return q
 }
 
+// SetPagination set the pagination field of the ObservationQuery struct.
 func (q *ObservationQuery) SetPagination(p *pagination.Pagination) *ObservationQuery {
 	q.Pagination = *p
 	return q

api/handlers/observations/service.go

@@ -1,40 +1,49 @@
+// Package observations handle the request of observations data from governor endpoint defined in the api.
 package observations
 
 import (
 	"context"
+
 	"github.com/certusone/wormhole/node/pkg/vaa"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/pagination"
 	"go.uber.org/zap"
 )
 
+// Service definition.
 type Service struct {
 	repo   *Repository
 	logger *zap.Logger
 }
 
+// NewService create a new Service.
 func NewService(dao *Repository, logger *zap.Logger) *Service {
 	return &Service{repo: dao, logger: logger.With(zap.String("module", "ObservationsService"))}
 }
 
+// FindAll get all the observations.
 func (s *Service) FindAll(ctx context.Context, p *pagination.Pagination) ([]*ObservationDoc, error) {
 	return s.repo.Find(ctx, Query().SetPagination(p))
 }
 
+// FindByChain get all the observations by chainID.
 func (s *Service) FindByChain(ctx context.Context, chain vaa.ChainID, p *pagination.Pagination) ([]*ObservationDoc, error) {
 	query := Query().SetChain(chain).SetPagination(p)
 	return s.repo.Find(ctx, query)
 }
 
+// FindByEmitter get all the observations by chainID and emitter address.
 func (s *Service) FindByEmitter(ctx context.Context, chain vaa.ChainID, emitter *vaa.Address, p *pagination.Pagination) ([]*ObservationDoc, error) {
 	query := Query().SetChain(chain).SetEmitter(emitter.String()).SetPagination(p)
 	return s.repo.Find(ctx, query)
 }
 
+// FindByVAA get all the observations for a VAA (chainID, emitter addrress and sequence number).
 func (s *Service) FindByVAA(ctx context.Context, chain vaa.ChainID, emitter *vaa.Address, seq uint64, p *pagination.Pagination) ([]*ObservationDoc, error) {
 	query := Query().SetChain(chain).SetEmitter(emitter.String()).SetSequence(seq).SetPagination(p)
 	return s.repo.Find(ctx, query)
 }
 
+// FindOne get a observation by chainID, emitter address, sequence, signer address and hash.
 func (s *Service) FindOne(ctx context.Context, chainID vaa.ChainID, emitterAddr *vaa.Address, seq uint64, signerAddr *vaa.Address, hash []byte) (*ObservationDoc, error) {
 	query := Query().SetChain(chainID).SetEmitter(emitterAddr.String()).SetSequence(seq).SetGuardianAddr(signerAddr.String()).SetHash(hash)
 	return s.repo.FindOne(ctx, query)

api/handlers/vaa/controller.go

@@ -1,83 +1,86 @@
+// Package observations handle the request of VAA data from governor endpoint defined in the api.
 package vaa
 
 import (
 	"fmt"
 
 	"github.com/gofiber/fiber/v2"
-	"github.com/wormhole-foundation/wormhole-explorer/api/errors"
 	"github.com/wormhole-foundation/wormhole-explorer/api/middleware"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
 	"go.uber.org/zap"
 )
 
+// Controller definition.
 type Controller struct {
 	srv    *Service
 	logger *zap.Logger
 }
 
+// NewController create a new controler.
 func NewController(serv *Service, logger *zap.Logger) *Controller {
 	return &Controller{srv: serv, logger: logger.With(zap.String("module", "VaaController"))}
 }
 
+// FindAll handler for the endpoint /vaas/.
 func (c *Controller) FindAll(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
 	vaas, err := c.srv.FindAll(ctx.Context(), p)
 	if err != nil {
-		fmt.Printf("error finding vaas: %v", err)
+		return err
 	}
 	return ctx.JSON(vaas)
 }
 
+// FindByChain handler for the endpoint /vaas/:chain.
 func (c *Controller) FindByChain(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+
-	chainID, err := middleware.ExtractChainID(ctx)
+	fmt.Println(ctx.Locals("requestid"))
+	p := middleware.GetPaginationFromContext(ctx)
+	chainID, err := middleware.ExtractChainID(ctx, c.logger)
 	if err != nil {
 		return err
 	}
 	vaas, err := c.srv.FindByChain(ctx.Context(), chainID, p)
 	if err != nil {
-		fmt.Printf("error finding vaas: %v", err)
+		return err
 	}
 	return ctx.JSON(vaas)
 }
 
+// FindByEmitter handler for the endpoint /vaas/:chain/:emitter.
 func (c *Controller) FindByEmitter(ctx *fiber.Ctx) error {
-	p := pagination.GetFromContext(ctx)
+	p := middleware.GetPaginationFromContext(ctx)
-	chainID, emitter, _, err := middleware.ExtractVAAParams(ctx)
+	chainID, emitter, err := middleware.ExtractVAAChainIDEmitter(ctx, c.logger)
-	if errors.IsOf(err, middleware.ErrMalformedChain, middleware.ErrMalformedAddr) {
+	if err != nil {
 		return err
 	}
 	vaas, err := c.srv.FindByEmitter(ctx.Context(), chainID, *emitter, p)
 	if err != nil {
-		//TODO logging
+		return err
-		fmt.Printf("error finding vaas: %v", err)
 	}
 	return ctx.JSON(vaas)
 }
 
+// FindById handler for the endpoint /vaas/:chain/:emitter/:sequence/:signer/:hash.
 func (c *Controller) FindById(ctx *fiber.Ctx) error {
-	chainID, emitter, seq, err := middleware.ExtractVAAParams(ctx)
+	chainID, emitter, seq, err := middleware.ExtractVAAParams(ctx, c.logger)
 	if err != nil {
 		return err
 	}
 	vaa, err := c.srv.FindById(ctx.Context(), chainID, *emitter, seq)
 	if err != nil {
-		//TODO logging
+		return err
-		fmt.Printf("error finding vaa: %v", err)
 	}
 	return ctx.JSON(vaa)
 }
 
 // FindSignedVAAByID get a signedVAA []byte from a chainID, emitter address and sequence.
 func (c *Controller) FindSignedVAAByID(ctx *fiber.Ctx) error {
-	chainID, emitter, seq, err := middleware.ExtractVAAParams(ctx)
+	chainID, emitter, seq, err := middleware.ExtractVAAParams(ctx, c.logger)
 	if err != nil {
-		// TODO: Handle InvalidArgument code (3) in the response.
 		return err
 	}
 	vaa, err := c.srv.FindById(ctx.Context(), chainID, *emitter, seq)
 	if err != nil {
-		// TODO: handle not found(5) and internal(13) response code.
 		return err
 	}
 	response := struct {

api/handlers/vaa/model.go

@@ -1,10 +1,12 @@
 package vaa
 
 import (
-	"github.com/certusone/wormhole/node/pkg/vaa"
 	"time"
+
+	"github.com/certusone/wormhole/node/pkg/vaa"
 )
 
+// VaaDoc represent an vaa document.
 type VaaDoc struct {
 	ID               string      `bson:"_id" json:"id"`
 	Version          uint8       `bson:"version" json:"version"`

api/handlers/vaa/repository.go

@@ -2,15 +2,19 @@ package vaa
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/certusone/wormhole/node/pkg/vaa"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
+	"github.com/pkg/errors"
+	errs "github.com/wormhole-foundation/wormhole-explorer/api/internal/errors"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/pagination"
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
 	"go.uber.org/zap"
 )
 
+// Repository definition
 type Repository struct {
 	db          *mongo.Database
 	logger      *zap.Logger
@@ -20,6 +24,7 @@ type Repository struct {
 	}
 }
 
+// NewRepository create a new Repository.
 func NewRepository(db *mongo.Database, logger *zap.Logger) *Repository {
 	return &Repository{db: db,
 		logger: logger.With(zap.String("module", "VaaRepository")),
@@ -29,6 +34,8 @@ func NewRepository(db *mongo.Database, logger *zap.Logger) *Repository {
 		}{vaas: db.Collection("vaas"), invalidVaas: db.Collection("invalid_vaas")}}
 }
 
+// Find get a list of *VaaDoc.
+// The input parameter [q *VaaQuery] define the filters to apply in the query.
 func (r *Repository) Find(ctx context.Context, q *VaaQuery) ([]*VaaDoc, error) {
 	if q == nil {
 		q = Query()
@@ -36,22 +43,37 @@ func (r *Repository) Find(ctx context.Context, q *VaaQuery) ([]*VaaDoc, error) {
 	sort := bson.D{{q.SortBy, q.GetSortInt()}}
 	cur, err := r.collections.vaas.Find(ctx, q.toBSON(), options.Find().SetLimit(q.PageSize).SetSkip(q.Offset).SetSort(sort))
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Find command to get vaas",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	var vaas []*VaaDoc
 	err = cur.All(ctx, &vaas)
 	if err != nil {
-		return nil, err
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed decoding cursor to []*VaaDoc", zap.Error(err), zap.Any("q", q),
+			zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
 	return vaas, err
 }
 
+// FindOne get *VaaDoc.
+// The input parameter [q *VaaQuery] define the filters to apply in the query.
 func (r *Repository) FindOne(ctx context.Context, q *VaaQuery) (*VaaDoc, error) {
 	var vaaDoc VaaDoc
 	err := r.collections.vaas.FindOne(ctx, q.toBSON()).Decode(&vaaDoc)
 	if err != nil {
-		return nil, err
+		if errors.Is(err, mongo.ErrNoDocuments) {
+			return nil, errs.ErrNotFound
+		}
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute FindOne command to get vaas",
+			zap.Error(err), zap.Any("q", q), zap.String("requestID", requestID))
+		return nil, errors.WithStack(err)
 	}
+
 	return &vaaDoc, err
 }
 
@@ -64,6 +86,9 @@ func (r *Repository) FindStats(ctx context.Context) ([]*VaaStats, error) {
 	}
 	c, err := r.collections.vaas.Aggregate(ctx, mongo.Pipeline{group})
 	if err != nil {
+		requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
+		r.logger.Error("failed execute Aggregate command to get vaa stats",
+			zap.Error(err), zap.String("requestID", requestID))
 		return nil, err
 	}
 	var stats []*VaaStats
@@ -71,6 +96,7 @@ func (r *Repository) FindStats(ctx context.Context) ([]*VaaStats, error) {
 	return stats, err
 }
 
+// VaaQuery respresent a query for the vaa mongodb document.
 type VaaQuery struct {
 	pagination.Pagination
 	chainId  vaa.ChainID
@@ -78,26 +104,31 @@ type VaaQuery struct {
 	sequence uint64
 }
 
+// Query create a new VaaQuery with default pagination vaues.
 func Query() *VaaQuery {
 	page := pagination.FirstPage()
 	return &VaaQuery{Pagination: *page}
 }
 
+// SetChain set the chainId field of the VaaQuery struct.
 func (q *VaaQuery) SetChain(chainID vaa.ChainID) *VaaQuery {
 	q.chainId = chainID
 	return q
 }
 
+// SetEmitter set the emitter field of the VaaQuery struct.
 func (q *VaaQuery) SetEmitter(emitter string) *VaaQuery {
 	q.emitter = emitter
 	return q
 }
 
+// SetSequence set the sequence field of the VaaQuery struct.
 func (q *VaaQuery) SetSequence(seq uint64) *VaaQuery {
 	q.sequence = seq
 	return q
 }
 
+// SetPagination set the pagination field of the VaaQuery struct.
 func (q *VaaQuery) SetPagination(p *pagination.Pagination) *VaaQuery {
 	q.Pagination = *p
 	return q

api/handlers/vaa/service.go

@@ -4,54 +4,60 @@ import (
 	"context"
 
 	"github.com/certusone/wormhole/node/pkg/vaa"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/pagination"
-	"github.com/wormhole-foundation/wormhole-explorer/api/services"
+	"github.com/wormhole-foundation/wormhole-explorer/api/response"
 	"go.uber.org/zap"
 )
 
+// Service definition.
 type Service struct {
 	repo   *Repository
 	logger *zap.Logger
 }
 
+// NewService create a new Service.
 func NewService(r *Repository, logger *zap.Logger) *Service {
 	return &Service{repo: r, logger: logger.With(zap.String("module", "VaaService"))}
 }
 
-func (s *Service) FindAll(ctx context.Context, p *pagination.Pagination) (*services.Response[[]*VaaDoc], error) {
+// FindAll get all the the vaa.
+func (s *Service) FindAll(ctx context.Context, p *pagination.Pagination) (*response.Response[[]*VaaDoc], error) {
 	if p == nil {
 		p = pagination.FirstPage()
 	}
 
 	query := Query().SetPagination(p)
 	vaas, err := s.repo.Find(ctx, query)
-	res := services.Response[[]*VaaDoc]{Data: vaas, Error: err}
+	res := response.Response[[]*VaaDoc]{Data: vaas}
 	return &res, err
 }
 
-func (s *Service) FindByChain(ctx context.Context, chain vaa.ChainID, p *pagination.Pagination) (*services.Response[[]*VaaDoc], error) {
+// FindByChain get all the vaa by chainID.
+func (s *Service) FindByChain(ctx context.Context, chain vaa.ChainID, p *pagination.Pagination) (*response.Response[[]*VaaDoc], error) {
 	query := Query().SetChain(chain).SetPagination(p)
 	vaas, err := s.repo.Find(ctx, query)
-	res := services.Response[[]*VaaDoc]{Data: vaas, Error: err}
+	res := response.Response[[]*VaaDoc]{Data: vaas}
 	return &res, err
 }
 
-func (s *Service) FindByEmitter(ctx context.Context, chain vaa.ChainID, emitter vaa.Address, p *pagination.Pagination) (*services.Response[[]*VaaDoc], error) {
+// FindByEmitter get all the vaa by chainID and emitter address.
+func (s *Service) FindByEmitter(ctx context.Context, chain vaa.ChainID, emitter vaa.Address, p *pagination.Pagination) (*response.Response[[]*VaaDoc], error) {
 	query := Query().SetChain(chain).SetEmitter(emitter.String()).SetPagination(p)
 	vaas, err := s.repo.Find(ctx, query)
-	res := services.Response[[]*VaaDoc]{Data: vaas, Error: err}
+	res := response.Response[[]*VaaDoc]{Data: vaas}
 	return &res, err
 }
 
-func (s *Service) FindById(ctx context.Context, chain vaa.ChainID, emitter vaa.Address, seq uint64) (*services.Response[*VaaDoc], error) {
+// FindById get a vaa by chainID, emitter address and sequence number.
+func (s *Service) FindById(ctx context.Context, chain vaa.ChainID, emitter vaa.Address, seq uint64) (*response.Response[*VaaDoc], error) {
 	query := Query().SetChain(chain).SetEmitter(emitter.String()).SetSequence(seq)
 	vaas, err := s.repo.FindOne(ctx, query)
-	res := services.Response[*VaaDoc]{Data: vaas, Error: err}
+	res := response.Response[*VaaDoc]{Data: vaas}
 	return &res, err
 }
 
-func (s *Service) GetVAAStats(ctx context.Context) (*services.Response[[]*VaaStats], error) {
+func (s *Service) GetVAAStats(ctx context.Context) (*response.Response[[]*VaaStats], error) {
 	stats, err := s.repo.FindStats(ctx)
-	res := services.Response[[]*VaaStats]{Data: stats, Error: err}
+	res := response.Response[[]*VaaStats]{Data: stats}
 	return &res, err
 }

api/internal/config/config.go

@@ -1,13 +1,23 @@
+// Package config implement a simple configuration package.
+// It define a type [AppConfig] that represent the aplication configuration and
+// use viper [https://github.com/spf13/viper] to load the configuration.
 package config
 
 import (
 	"bytes"
 	"encoding/json"
+	"strings"
+
 	ipfslog "github.com/ipfs/go-log/v2"
 	"github.com/spf13/viper"
-	"strings"
 )
 
+const (
+	RunModeProduction   = "PRODUCTION"
+	RunModeDevelopmernt = "DEVELOPMENT"
+)
+
+// AppConfig defines the configuration for the app.
 type AppConfig struct {
 	DB struct {
 		URL string
@@ -15,11 +25,12 @@ type AppConfig struct {
 		Name string
 	}
 
-	PORT int
+	PORT     int
-
 	LogLevel string
+	RunMode  string
 }
 
+// GetLogLevel get zapcore.Level define in the configuraion.
 func (cfg *AppConfig) GetLogLevel() (ipfslog.LogLevel, error) {
 	return ipfslog.LevelFromString(cfg.LogLevel)
 }
@@ -27,6 +38,8 @@ func (cfg *AppConfig) GetLogLevel() (ipfslog.LogLevel, error) {
 func init() {
 	viper.SetDefault("port", 8000)
 	viper.SetDefault("loglevel", "INFO")
+	viper.SetDefault("runmode", "PRODUCTION")
+
 	// Consider environment variables in unmarshall doesn't work unless doing this: https://github.com/spf13/viper/issues/188#issuecomment-1168898503
 	b, err := json.Marshal(AppConfig{})
 	if err != nil {
@@ -50,6 +63,7 @@ func init() {
 	viper.AutomaticEnv()
 }
 
+// Get returns the app configuration.
 func Get() (*AppConfig, error) {
 	var cfg AppConfig
 	err := viper.Unmarshal(&cfg)

api/internal/db/db.go

@@ -1,11 +1,14 @@
+// Package db handle mongodb connections.
 package db
 
 import (
 	"context"
+
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
 )
 
+// Connect create a new mongo db client for the options defined in the input param url.
 func Connect(ctx context.Context, url string) (*mongo.Client, error) {
 	cli, err := mongo.NewClient(options.Client().ApplyURI(url))
 	if err != nil {

api/internal/errors/error.go

@@ -0,0 +1,10 @@
+package errors
+
+import "errors"
+
+// Error definitions to use in service and repository layers.
+var (
+	ErrMalformedQuery = errors.New("MALFORMED_QUERY")
+	ErrNotFound       = errors.New("NOT FOUND")
+	ErrInternalError  = errors.New("INTERNAL ERROR")
+)

api/internal/pagination/pagination.go

@@ -1,5 +1,6 @@
 package pagination
 
+// Pagination definition.
 type Pagination struct {
 	Offset    int64
 	PageSize  int64
@@ -7,41 +8,49 @@ type Pagination struct {
 	SortBy    string
 }
 
+// FirstPage return a *Pagination with default values offset and page size.
 func FirstPage() *Pagination {
 	return &Pagination{Offset: 0, PageSize: 50}
 }
 
+// BuildPagination create a new *Pagination.
 func BuildPagination(page, pageSize int64, sortOrder, sortBy string) *Pagination {
 	p := Pagination{}
 	p.SetPage(page).SetPageSize(pageSize).SetSortOrder(sortOrder).SetSortBy(sortBy)
 	return &p
 }
 
+// SetPageSize set the PageSize field of the Pagination struct.
 func (p *Pagination) SetPageSize(limit int64) *Pagination {
 	p.PageSize = limit
 	return p
 }
 
+// SetOffset set the Offset field of the Pagination struct.
 func (p *Pagination) SetOffset(offset int64) *Pagination {
 	p.Offset = offset
 	return p
 }
 
+// SetPage set the Page field of the Pagination struct.
 func (p *Pagination) SetPage(page int64) *Pagination {
 	p.Offset = page * p.PageSize
 	return p
 }
 
+// SetSortOrder set the SortOrder field of the Pagination struct.
 func (p *Pagination) SetSortOrder(order string) *Pagination {
 	p.SortOrder = order
 	return p
 }
 
+// SetSortBy set the SortBy field of the Pagination struct.
 func (p *Pagination) SetSortBy(by string) *Pagination {
 	p.SortBy = by
 	return p
 }
 
+// GetSortInt mapping to mongodb sort values.
 func (p *Pagination) GetSortInt() int {
 	if p.SortOrder == "ASC" {
 		return 1

api/main.go

@@ -14,12 +14,13 @@ import (
 	"github.com/gofiber/fiber/v2/middleware/logger"
 	"github.com/gofiber/fiber/v2/middleware/requestid"
 	ipfslog "github.com/ipfs/go-log/v2"
-	"github.com/wormhole-foundation/wormhole-explorer/api/config"
+	"github.com/wormhole-foundation/wormhole-explorer/api/handlers/governor"
-	"github.com/wormhole-foundation/wormhole-explorer/api/db"
+	"github.com/wormhole-foundation/wormhole-explorer/api/handlers/observations"
-	"github.com/wormhole-foundation/wormhole-explorer/api/governor"
+	"github.com/wormhole-foundation/wormhole-explorer/api/handlers/vaa"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/config"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/db"
 	"github.com/wormhole-foundation/wormhole-explorer/api/middleware"
-	"github.com/wormhole-foundation/wormhole-explorer/api/observations"
+	"github.com/wormhole-foundation/wormhole-explorer/api/response"
-	"github.com/wormhole-foundation/wormhole-explorer/api/vaa"
 )
 
 var cacheConfig = cache.Config{
@@ -54,7 +55,7 @@ func main() {
 		panic(err)
 	}
 
-	rootLogger := ipfslog.Logger("wormhole-spy").Desugar()
+	rootLogger := ipfslog.Logger("wormhole-api").Desugar()
 	ipfslog.SetAllLoggers(lvl)
 
 	// Setup DB
@@ -79,8 +80,9 @@ func main() {
 	observationsCtrl := observations.NewController(obsService, rootLogger)
 	governorCtrl := governor.NewController(governorService, rootLogger)
 
-	// Setup API
+	// Setup app with custom error handling.
-	app := fiber.New()
+	response.SetEnableStackTrace(*cfg)
+	app := fiber.New(fiber.Config{ErrorHandler: middleware.ErrorHandler})
 
 	// Middleware
 	prometheus := fiberprometheus.New("wormscan")

api/middleware/error_handler.go

@@ -0,0 +1,32 @@
+// package middleare contains all the middleware function to use in the API.
+package middleware
+
+import (
+	"github.com/pkg/errors"
+	errs "github.com/wormhole-foundation/wormhole-explorer/api/internal/errors"
+	"github.com/wormhole-foundation/wormhole-explorer/api/response"
+
+	"github.com/gofiber/fiber/v2"
+)
+
+// ErrorHandler define a fiber custom error handler. This function process all errors
+// returned from any handlers in the stack.
+//
+// To setup this function we must set the ErrorHandler field of the fiber.Config struct
+// with this function and create a new fiber with this config.
+//
+// example: fiber.New(fiber.Config{ErrorHandler: errs.APIErrorHandler}
+func ErrorHandler(ctx *fiber.Ctx, err error) error {
+	var apiError response.APIError
+	switch {
+	case errors.As(err, &apiError):
+		ctx.Status(apiError.StatusCode).JSON(apiError)
+	case errors.Is(err, errs.ErrNotFound):
+		apiError = response.NewNotFoundError(ctx)
+		ctx.Status(fiber.StatusNotFound).JSON(apiError)
+	default:
+		apiError = response.NewInternalError(ctx, err)
+		ctx.Status(fiber.StatusInternalServerError).JSON(apiError)
+	}
+	return nil
+}

api/middleware/extract_pagination.go

@@ -1,15 +1,50 @@
+// package middleare contains all the middleware function to use in the API.
 package middleware
 
 import (
-	"github.com/gofiber/fiber/v2"
-	"github.com/wormhole-foundation/wormhole-explorer/api/pagination"
 	"net/http"
+	"strconv"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/pagination"
 )
 
+// ExtractPagination middleware invoke pagination.ExtractPagination.
 func ExtractPagination(c *fiber.Ctx) error {
 	if c.Method() != http.MethodGet {
 		return c.Next()
 	}
-	pagination.ExtractPagination(c)
+	extractPagination(c)
 	return c.Next()
 }
+
+// extractPagination get pagination query params and build a *Pagination.
+func extractPagination(ctx *fiber.Ctx) (*pagination.Pagination, error) {
+	pageNumberStr := ctx.Query("page", "0")
+	pageNumber, err := strconv.ParseInt(pageNumberStr, 10, 64)
+	if err != nil {
+		return nil, err
+	}
+
+	pageSizeStr := ctx.Query("pageSize", "50")
+	pageSize, err := strconv.ParseInt(pageSizeStr, 10, 64)
+	if err != nil {
+		return nil, err
+	}
+
+	sortOrder := ctx.Query("sortOrder", "DESC")
+	sortBy := ctx.Query("sortBy", "indexedAt")
+
+	p := pagination.BuildPagination(pageNumber, pageSize, sortOrder, sortBy)
+	ctx.Locals("pagination", p)
+	return p, nil
+}
+
+// GetPaginationFromContext get pagination from context.
+func GetPaginationFromContext(ctx *fiber.Ctx) *pagination.Pagination {
+	p := ctx.Locals("pagination")
+	if p == nil {
+		return nil
+	}
+	return p.(*pagination.Pagination)
+}

api/middleware/extract_parameters.go

@@ -1,67 +1,114 @@
+// package middleare contains all the middleware function to use in the API.
 package middleware
 
 import (
-	"errors"
+	"fmt"
 	"strconv"
 
 	"github.com/certusone/wormhole/node/pkg/vaa"
 	"github.com/gofiber/fiber/v2"
+	"github.com/pkg/errors"
+	"github.com/wormhole-foundation/wormhole-explorer/api/response"
+	"go.uber.org/zap"
 )
 
-var (
+// ExtractChainID get chain parameter from route path.
-	ErrMalformedChain           = errors.New("WRONG_CHAIN_ID")
+func ExtractChainID(c *fiber.Ctx, l *zap.Logger) (vaa.ChainID, error) {
-	ErrMalformedAddr            = errors.New("MALFORMED_EMITTER_ADDR")
-	ErrMalformedSequence        = errors.New("MALFORMED_SEQUENCE_NUMBER")
-	ErrMalFormedGuardianAddress = errors.New("MALFORMED_GUARDIAN_ADDR")
-)
-
-func ExtractChainID(c *fiber.Ctx) (vaa.ChainID, error) {
 	chain, err := c.ParamsInt("chain")
 	if err != nil {
-		return vaa.ChainIDUnset, ErrMalformedChain
+		requestID := fmt.Sprintf("%v", c.Locals("requestid"))
+		l.Error("failed to get chain parameter", zap.Error(err), zap.Int("chain", chain),
+			zap.String("requestID", requestID))
+
+		return vaa.ChainIDUnset, response.NewInvalidParamError(c, "WRONG CHAIN ID", errors.WithStack(err))
 	}
 	return vaa.ChainID(chain), nil
 }
 
-func ExtractEmitterAddr(c *fiber.Ctx) (*vaa.Address, error) {
+// ExtractEmitterAddr get emitter parameter from route path.
+func ExtractEmitterAddr(c *fiber.Ctx, l *zap.Logger) (*vaa.Address, error) {
 	emitterStr := c.Params("emitter")
 	emitter, err := vaa.StringToAddress(emitterStr)
 	if err != nil {
-		return nil, ErrMalformedAddr
+		requestID := fmt.Sprintf("%v", c.Locals("requestid"))
+		l.Error("failed to covert emitter to address", zap.Error(err), zap.String("emitterStr", emitterStr),
+			zap.String("requestID", requestID))
+		return nil, response.NewInvalidParamError(c, "MALFORMED EMITTER_ADDR", errors.WithStack(err))
 	}
 	return &emitter, nil
 }
 
-func ExtractSequence(c *fiber.Ctx) (uint64, error) {
+// ExtractSequence get sequence parameter from route path.
+func ExtractSequence(c *fiber.Ctx, l *zap.Logger) (uint64, error) {
 	sequence := c.Params("sequence")
 	seq, err := strconv.ParseUint(sequence, 10, 64)
 	if err != nil {
-		return 0, err
+		requestID := fmt.Sprintf("%v", c.Locals("requestid"))
+		l.Error("failed to get sequence parameter", zap.Error(err), zap.String("sequence", sequence),
+			zap.String("requestID", requestID))
+		return 0, response.NewInvalidParamError(c, "MALFORMED SEQUENCE NUMBER", errors.WithStack(err))
 	}
 	return seq, nil
 }
 
-func ExtractGuardianAddress(c *fiber.Ctx) (string, error) {
+// ExtractGuardianAddress get guardian address from route path.
+func ExtractGuardianAddress(c *fiber.Ctx, l *zap.Logger) (string, error) {
 	//TODO: check guardianAddress [vaa.StringToAddress(emitterStr)]
 	guardianAddress := c.Params("guardian_address")
 	if guardianAddress == "" {
-		return "", ErrMalFormedGuardianAddress
+		return "", response.NewInvalidParamError(c, "MALFORMED GUARDIAN ADDR", nil)
 	}
 	return guardianAddress, nil
 }
 
-func ExtractVAAParams(c *fiber.Ctx) (vaa.ChainID, *vaa.Address, uint64, error) {
+// ExtractVAAParams get VAA chain, address from route path.
-	chainID, err := ExtractChainID(c)
+func ExtractVAAChainIDEmitter(c *fiber.Ctx, l *zap.Logger) (vaa.ChainID, *vaa.Address, error) {
+	chainID, err := ExtractChainID(c, l)
+	if err != nil {
+		return vaa.ChainIDUnset, nil, err
+	}
+	address, err := ExtractEmitterAddr(c, l)
+	if err != nil {
+		return chainID, nil, err
+	}
+	return chainID, address, nil
+}
+
+// ExtractVAAParams get VAAA chain, address and sequence from route path.
+func ExtractVAAParams(c *fiber.Ctx, l *zap.Logger) (vaa.ChainID, *vaa.Address, uint64, error) {
+	chainID, err := ExtractChainID(c, l)
 	if err != nil {
 		return vaa.ChainIDUnset, nil, 0, err
 	}
-	address, err := ExtractEmitterAddr(c)
+	address, err := ExtractEmitterAddr(c, l)
 	if err != nil {
 		return chainID, nil, 0, err
 	}
-	seq, err := ExtractSequence(c)
+	seq, err := ExtractSequence(c, l)
 	if err != nil {
 		return chainID, address, 0, err
 	}
 	return chainID, address, seq, nil
 }
+
+// ExtractObservationSigner get signer from route path.
+func ExtractObservationSigner(c *fiber.Ctx, l *zap.Logger) (*vaa.Address, error) {
+	signer := c.Params("signer")
+	signerAddr, err := vaa.StringToAddress(signer)
+	if err != nil {
+		requestID := fmt.Sprintf("%v", c.Locals("requestid"))
+		l.Error("failed to covert signer to address", zap.Error(err), zap.String("signer", signer),
+			zap.String("requestID", requestID))
+		return nil, response.NewInvalidParamError(c, "MALFORMED SIGNER", errors.WithStack(err))
+	}
+	return &signerAddr, nil
+}
+
+// ExtractObservationHash get a hash from route path.
+func ExtractObservationHash(c *fiber.Ctx, l *zap.Logger) (string, error) {
+	hash := c.Params("hash")
+	if hash == "" {
+		return "", response.NewInvalidParamError(c, "MALFORMED HASH", nil)
+	}
+	return hash, nil
+}

api/pagination/rest_pagination.go

@@ -1,35 +0,0 @@
-package pagination
-
-import (
-	"github.com/gofiber/fiber/v2"
-	"strconv"
-)
-
-func ExtractPagination(ctx *fiber.Ctx) (*Pagination, error) {
-	pageNumberStr := ctx.Query("page", "0")
-	pageNumber, err := strconv.ParseInt(pageNumberStr, 10, 64)
-	if err != nil {
-		return nil, err
-	}
-
-	pageSizeStr := ctx.Query("pageSize", "50")
-	pageSize, err := strconv.ParseInt(pageSizeStr, 10, 64)
-	if err != nil {
-		return nil, err
-	}
-
-	sortOrder := ctx.Query("sortOrder", "DESC")
-	sortBy := ctx.Query("sortBy", "indexedAt")
-
-	p := BuildPagination(pageNumber, pageSize, sortOrder, sortBy)
-	ctx.Locals("pagination", p)
-	return p, nil
-}
-
-func GetFromContext(ctx *fiber.Ctx) *Pagination {
-	p := ctx.Locals("pagination")
-	if p == nil {
-		return nil
-	}
-	return p.(*Pagination)
-}

api/response/error.go

@@ -0,0 +1,113 @@
+// The response package defines the success and error response type.
+// It define a type [AppError] that represent the api error response.
+// Its define a custom error handling for the api.
+package response
+
+import (
+	"fmt"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/wormhole-foundation/wormhole-explorer/api/internal/config"
+)
+
+// API error codes. These error code are the same used in guardian API.
+const (
+	InvalidParam = 3
+	NotFound     = 5
+	Internal     = 13
+)
+
+var enableStackTrace bool
+
+// SetEnableStackTrace enable/disable send the stacktrace field in the response.
+func SetEnableStackTrace(cfg config.AppConfig) {
+	if cfg.RunMode == config.RunModeDevelopmernt {
+		enableStackTrace = true
+		return
+	}
+	enableStackTrace = false
+}
+
+// APIError api error response.
+// This structure is defined to be aligned with the way the guardian API handles the error response.
+type APIError struct {
+	StatusCode int           `json:"-"`
+	Code       int           `json:"code"` // support to guardian-api code.
+	Message    string        `json:"message"`
+	Details    []ErrorDetail `json:"details"`
+}
+
+// ErrorDetail definition.
+// This structure contains the requestID and the stacktrace of the error.
+type ErrorDetail struct {
+	RequestID  string `json:"request_id"`
+	StackTrace string `json:"stack_trace,omitempty"`
+}
+
+// Error interface implementation.
+func (a APIError) Error() string {
+	return fmt.Sprintf("code: %d, message: %s, details: %v", a.Code, a.Message, a.Details)
+}
+
+// NewApiError create a new api response.
+func NewApiError(ctx *fiber.Ctx, statusCode, code int, message string, err error) APIError {
+	detail := ErrorDetail{
+		RequestID: fmt.Sprintf("%v", ctx.Locals("requestid")),
+	}
+	if enableStackTrace && err != nil {
+		detail.StackTrace = fmt.Sprintf("%+v\n", err)
+	}
+	return APIError{
+		StatusCode: fiber.StatusBadRequest,
+		Code:       InvalidParam,
+		Message:    message,
+		Details:    []ErrorDetail{detail},
+	}
+}
+
+// NewInvalidParamError create a invalid param Error.
+func NewInvalidParamError(ctx *fiber.Ctx, message string, err error) APIError {
+	if message == "" {
+		message = "INVALID PARAM"
+	}
+	detail := ErrorDetail{
+		RequestID: fmt.Sprintf("%v", ctx.Locals("requestid")),
+	}
+	if enableStackTrace && err != nil {
+		detail.StackTrace = fmt.Sprintf("%+v\n", err)
+	}
+	return APIError{
+		StatusCode: fiber.StatusBadRequest,
+		Code:       InvalidParam,
+		Message:    message,
+		Details:    []ErrorDetail{detail},
+	}
+}
+
+// NewInternalError create a new APIError for Internal Errors.
+func NewInternalError(ctx *fiber.Ctx, err error) APIError {
+	detail := ErrorDetail{
+		RequestID: fmt.Sprintf("%v", ctx.Locals("requestid")),
+	}
+	if enableStackTrace && err != nil {
+		detail.StackTrace = fmt.Sprintf("%+v\n", err)
+	}
+	return APIError{
+		StatusCode: fiber.StatusInternalServerError,
+		Code:       Internal,
+		Message:    "INTERNAL ERROR",
+		Details:    []ErrorDetail{detail},
+	}
+}
+
+// NewNotFoundError create a new APIError for Not Found errors.
+func NewNotFoundError(ctx *fiber.Ctx) APIError {
+	return APIError{
+		StatusCode: fiber.StatusNotFound,
+		Code:       NotFound,
+		Message:    "NOT FOUND",
+		Details: []ErrorDetail{{
+			RequestID: fmt.Sprintf("%v", ctx.Locals("requestid")),
+		}},
+	}
+}

api/response/success.go

@@ -1,11 +1,13 @@
-package services
+// The response package defines the success and error response type.
+package response
 
+// ResponsePagination definition.
 type ResponsePagination struct {
 	Next string `json:"next"`
 }
 
+// Response represent a success API response.
 type Response[T any] struct {
 	Data       T                  `json:"data"`
-	Error      error              `json:"error"`
 	Pagination ResponsePagination `json:"pagination"`
 }