Parse config settings

common/settings/structs.go

@@ -0,0 +1,38 @@
+package settings
+
+import (
+	"fmt"
+
+	"github.com/joho/godotenv"
+	"github.com/kelseyhightower/envconfig"
+)
+
+// MongoDB contains configuration settings for a MongoDB database.
+type MongoDB struct {
+	MongodbUri      string `split_words:"true" required:"true"`
+	MongodbDatabase string `split_words:"true" required:"true"`
+}
+
+// Logger contains configuration settings for a logger.
+type Logger struct {
+	LogLevel string `split_words:"true" default:"INFO"`
+}
+
+// LoadFromEnv loads the configuration settings from environment variables.
+//
+// If there is a .env file in the current directory, it will be used to
+// populate the environment variables.
+func LoadFromEnv[T any]() (*T, error) {
+
+	// Load .env file (if it exists)
+	_ = godotenv.Load()
+
+	// Load environment variables into a struct
+	var settings T
+	err := envconfig.Process("", &settings)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read config from environment: %w", err)
+	}
+
+	return &settings, nil
+}

core-contract-watcher/cmd/service/main.go

@@ -1,5 +1,32 @@
 package main
 
+import (
+	"context"
+	"log"
+
+	"github.com/wormhole-foundation/wormhole-explorer/common/logger"
+	"github.com/wormhole-foundation/wormhole-explorer/common/settings"
+	"github.com/wormhole-foundation/wormhole-explorer/core-contract-watcher/config"
+)
+
 func main() {
 
+	// Load config
+	cfg, err := settings.LoadFromEnv[config.ServiceSettings]()
+	if err != nil {
+		log.Fatal("Error loading config: ", err)
+	}
+
+	// Build rootLogger
+	rootLogger := logger.New("wormhole-explorer-core-contract-watcher", logger.WithLevel(cfg.LogLevel))
+
+	// Create top-level context
+	_, rootCtxCancel := context.WithCancel(context.Background())
+
+	rootLogger.Info("starting service...")
+
+	// Graceful shutdown
+	rootLogger.Info("cancelling root context...")
+	rootCtxCancel()
+	rootLogger.Info("terminated")
 }

core-contract-watcher/config/structs.go

@@ -0,0 +1,11 @@
+package config
+
+import (
+	"github.com/wormhole-foundation/wormhole-explorer/common/settings"
+)
+
+// ServiceSettings models the configuration settings for the core-contract-watcher service.
+type ServiceSettings struct {
+	settings.Logger
+	settings.MongoDB
+}