Merge PR #5136: Refactor CLIContext to allow multi-chain verifiers

CHANGELOG.md

@@ -80,9 +80,26 @@ correct version via: `pkgutil --pkg-info=com.apple.pkg.CLTools_Executables`.
 * (keys) [\#5097](https://github.com/cosmos/cosmos-sdk/pull/5097) New `keys migrate` command to assist users migrate their keys
 to the new keyring.
 
-
 ### Improvements
 
+* (cli) [\#5116](https://github.com/cosmos/cosmos-sdk/issues/5116) The `CLIContext` now supports multiple verifiers
+when connecting to multiple chains. The connecting chain's `CLIContext` will have to have the correct
+chain ID and node URI or client set. To use a `CLIContext` with a verifier for another chain:
+
+  ```go
+  // main or parent chain (chain as if you're running without IBC)
+  mainCtx := context.NewCLIContext()
+
+  // connecting IBC chain
+  sideCtx := context.NewCLIContext().
+    WithChainID(sideChainID).
+    WithNodeURI(sideChainNodeURI) // or .WithClient(...)
+
+  sideCtx = sideCtx.WithVerifier(
+    context.CreateVerifier(sideCtx, context.DefaultVerifierCacheSize),
+  )
+  ```
+
 * (modules) [\#5017](https://github.com/cosmos/cosmos-sdk/pull/5017) The `x/auth` package now supports
 generalized genesis accounts through the `GenesisAccount` interface.
 * (modules) [\#4762](https://github.com/cosmos/cosmos-sdk/issues/4762) Deprecate remove and add permissions in ModuleAccount.

client/context/context.go

@@ -1,20 +1,16 @@
 package context
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"os"
-	"path/filepath"
 
 	"github.com/pkg/errors"
 	"github.com/spf13/viper"
 	yaml "gopkg.in/yaml.v2"
 
 	"github.com/tendermint/tendermint/libs/cli"
-	"github.com/tendermint/tendermint/libs/log"
 	tmlite "github.com/tendermint/tendermint/lite"
-	tmliteProxy "github.com/tendermint/tendermint/lite/proxy"
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 
 	"github.com/cosmos/cosmos-sdk/client/flags"
@@ -24,27 +20,23 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
-var (
-	verifier     tmlite.Verifier
-	verifierHome string
-)
-
 // CLIContext implements a typical CLI context created in SDK modules for
 // transaction handling and queries.
 type CLIContext struct {
 	Codec         *codec.Codec
 	Client        rpcclient.Client
+	ChainID       string
 	Keybase       cryptokeys.Keybase
 	Output        io.Writer
 	OutputFormat  string
 	Height        int64
+	HomeDir       string
 	NodeURI       string
 	From          string
 	TrustNode     bool
 	UseLedger     bool
 	BroadcastMode string
 	Verifier      tmlite.Verifier
-	VerifierHome  string
 	Simulate      bool
 	GenerateOnly  bool
 	FromAddress   sdk.AccAddress
@@ -55,7 +47,10 @@ type CLIContext struct {
 
 // NewCLIContextWithFrom returns a new initialized CLIContext with parameters from the
 // command line using Viper. It takes a key name or address and populates the FromName and
-// FromAddress field accordingly.
+// FromAddress field accordingly. It will also create Tendermint verifier using
+// the chain ID, home directory and RPC URI provided by the command line. If using
+// a CLIContext in tests or any non CLI-based environment, the verifier will not
+// be created and will be set as nil because FlagTrustNode must be set.
 func NewCLIContextWithFrom(from string) CLIContext {
 	var nodeURI string
 	var rpc rpcclient.Client
@@ -74,23 +69,18 @@ func NewCLIContextWithFrom(from string) CLIContext {
 		}
 	}
 
-	// We need to use a single verifier for all contexts
+	ctx := CLIContext{
-	if verifier == nil || verifierHome != viper.GetString(flags.FlagHome) {
-		verifier = createVerifier()
-		verifierHome = viper.GetString(flags.FlagHome)
-	}
-
-	return CLIContext{
 		Client:        rpc,
+		ChainID:       viper.GetString(flags.FlagChainID),
 		Output:        os.Stdout,
 		NodeURI:       nodeURI,
 		From:          viper.GetString(flags.FlagFrom),
 		OutputFormat:  viper.GetString(cli.OutputFlag),
 		Height:        viper.GetInt64(flags.FlagHeight),
+		HomeDir:       viper.GetString(flags.FlagHome),
 		TrustNode:     viper.GetBool(flags.FlagTrustNode),
 		UseLedger:     viper.GetBool(flags.FlagUseLedger),
 		BroadcastMode: viper.GetString(flags.FlagBroadcastMode),
-		Verifier:      verifier,
 		Simulate:      viper.GetBool(flags.FlagDryRun),
 		GenerateOnly:  genOnly,
 		FromAddress:   fromAddress,
@@ -98,58 +88,21 @@ func NewCLIContextWithFrom(from string) CLIContext {
 		Indent:        viper.GetBool(flags.FlagIndentResponse),
 		SkipConfirm:   viper.GetBool(flags.FlagSkipConfirmation),
 	}
+
+	// create a verifier for the specific chain ID and RPC client
+	verifier, err := CreateVerifier(ctx, DefaultVerifierCacheSize)
+	if err != nil && viper.IsSet(flags.FlagTrustNode) {
+		fmt.Printf("failed to create verifier: %s\n", err)
+		os.Exit(1)
+	}
+
+	return ctx.WithVerifier(verifier)
 }
 
 // NewCLIContext returns a new initialized CLIContext with parameters from the
 // command line using Viper.
 func NewCLIContext() CLIContext { return NewCLIContextWithFrom(viper.GetString(flags.FlagFrom)) }
 
-func createVerifier() tmlite.Verifier {
-	trustNodeDefined := viper.IsSet(flags.FlagTrustNode)
-	if !trustNodeDefined {
-		return nil
-	}
-
-	trustNode := viper.GetBool(flags.FlagTrustNode)
-	if trustNode {
-		return nil
-	}
-
-	chainID := viper.GetString(flags.FlagChainID)
-	home := viper.GetString(flags.FlagHome)
-	nodeURI := viper.GetString(flags.FlagNode)
-
-	var errMsg bytes.Buffer
-	if chainID == "" {
-		errMsg.WriteString("--chain-id ")
-	}
-	if home == "" {
-		errMsg.WriteString("--home ")
-	}
-	if nodeURI == "" {
-		errMsg.WriteString("--node ")
-	}
-	if errMsg.Len() != 0 {
-		fmt.Printf("Must specify these options: %s when --trust-node is false\n", errMsg.String())
-		os.Exit(1)
-	}
-
-	node := rpcclient.NewHTTP(nodeURI, "/websocket")
-	cacheSize := 10 // TODO: determine appropriate cache size
-	verifier, err := tmliteProxy.NewVerifier(
-		chainID, filepath.Join(home, ".lite_verifier"),
-		node, log.NewNopLogger(), cacheSize,
-	)
-
-	if err != nil {
-		fmt.Printf("Create verifier failed: %s\n", err.Error())
-		fmt.Printf("Please check network connection and verify the address of the node to connect to\n")
-		os.Exit(1)
-	}
-
-	return verifier
-}
-
 // WithCodec returns a copy of the context with an updated codec.
 func (ctx CLIContext) WithCodec(cdc *codec.Codec) CLIContext {
 	ctx.Codec = cdc
@@ -200,12 +153,18 @@ func (ctx CLIContext) WithUseLedger(useLedger bool) CLIContext {
 	return ctx
 }
 
-// WithVerifier - return a copy of the context with an updated Verifier
+// WithVerifier returns a copy of the context with an updated Verifier.
 func (ctx CLIContext) WithVerifier(verifier tmlite.Verifier) CLIContext {
 	ctx.Verifier = verifier
 	return ctx
 }
 
+// WithChainID returns a copy of the context with an updated chain ID.
+func (ctx CLIContext) WithChainID(chainID string) CLIContext {
+	ctx.ChainID = chainID
+	return ctx
+}
+
 // WithGenerateOnly returns a copy of the context with updated GenerateOnly value
 func (ctx CLIContext) WithGenerateOnly(generateOnly bool) CLIContext {
 	ctx.GenerateOnly = generateOnly

client/context/verifier.go

@@ -0,0 +1,51 @@
+package context
+
+import (
+	"path/filepath"
+
+	"github.com/pkg/errors"
+	"github.com/tendermint/tendermint/libs/log"
+	tmlite "github.com/tendermint/tendermint/lite"
+	tmliteproxy "github.com/tendermint/tendermint/lite/proxy"
+	rpcclient "github.com/tendermint/tendermint/rpc/client"
+)
+
+const (
+	verifierDir = ".lite_verifier"
+
+	// DefaultVerifierCacheSize defines the default Tendermint cache size.
+	DefaultVerifierCacheSize = 10
+)
+
+// CreateVerifier returns a Tendermint verifier from a CLIContext object and
+// cache size. An error is returned if the CLIContext is missing required values
+// or if the verifier could not be created. A CLIContext must at the very least
+// have the chain ID and home directory set. If the CLIContext has TrustNode
+// enabled, no verifier will be created.
+func CreateVerifier(ctx CLIContext, cacheSize int) (tmlite.Verifier, error) {
+	if ctx.TrustNode {
+		return nil, nil
+	}
+
+	switch {
+	case ctx.ChainID == "":
+		return nil, errors.New("must provide a valid chain ID to create verifier")
+
+	case ctx.HomeDir == "":
+		return nil, errors.New("must provide a valid home directory to create verifier")
+
+	case ctx.Client == nil && ctx.NodeURI == "":
+		return nil, errors.New("must provide a valid RPC client or RPC URI to create verifier")
+	}
+
+	// create an RPC client based off of the RPC URI if no RPC client exists
+	client := ctx.Client
+	if client == nil {
+		client = rpcclient.NewHTTP(ctx.NodeURI, "/websocket")
+	}
+
+	return tmliteproxy.NewVerifier(
+		ctx.ChainID, filepath.Join(ctx.HomeDir, ctx.ChainID, verifierDir),
+		client, log.NewNopLogger(), cacheSize,
+	)
+}

client/context/verifier_test.go

@@ -0,0 +1,35 @@
+package context_test
+
+import (
+	"io/ioutil"
+	"testing"
+
+	"github.com/cosmos/cosmos-sdk/client/context"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreateVerifier(t *testing.T) {
+	tmpDir, err := ioutil.TempDir("", "example")
+	require.NoError(t, err)
+
+	testCases := []struct {
+		name      string
+		ctx       context.CLIContext
+		expectErr bool
+	}{
+		{"no chain ID", context.CLIContext{}, true},
+		{"no home directory", context.CLIContext{}.WithChainID("test"), true},
+		{"no client or RPC URI", context.CLIContext{HomeDir: tmpDir}.WithChainID("test"), true},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			verifier, err := context.CreateVerifier(tc.ctx, context.DefaultVerifierCacheSize)
+			require.Equal(t, tc.expectErr, err != nil, err)
+
+			if !tc.expectErr {
+				require.NotNil(t, verifier)
+			}
+		})
+	}
+}