feat: add ExposeAdditionalPorts config option

for cosmos chains, ExposeAdditionalPorts takes a list of port ids that
will be exposed on all validators and full nodes for the chains on
random host ports.

extends the ethermint test by exposing the EVM & verifying the port
actually gets exposed.

chain/cosmos/chain_node.go

@@ -1058,6 +1058,9 @@ func (tn *ChainNode) CreateNodeContainer(ctx context.Context) error {
 	for k, v := range sentryPorts {
 		usingPorts[k] = v
 	}
+	for _, port := range chainCfg.ExposeAdditionalPorts {
+		usingPorts[nat.Port(port)] = []nat.PortBinding{}
+	}
 
 	// to prevent port binding conflicts, host port overrides are only exposed on the first validator node.
 	if tn.Validator && tn.Index == 0 && chainCfg.HostPortOverride != nil {
@@ -1377,3 +1380,16 @@ func (tn *ChainNode) SendICABankTransfer(ctx context.Context, connectionID, from
 	_, err := tn.SendICATx(ctx, fromAddr, connectionID, ir, msgs, icaTxMemo, "proto3")
 	return err
 }
+
+// GetHostAddress returns the host-accessible url for a port in the container.
+// This is useful for finding the url & random host port for ports exposed via ChainConfig.ExposeAdditionalPorts
+func (tn *ChainNode) GetHostAddress(ctx context.Context, portID string) (string, error) {
+	ports, err := tn.containerLifecycle.GetHostPorts(ctx, portID)
+	if err != nil {
+		return "", err
+	}
+	if len(ports) == 0 || ports[0] == "" {
+		return "", fmt.Errorf("no port with id '%s' found", portID)
+	}
+	return "http://" + ports[0], nil
+}

chainspec.go

@@ -62,6 +62,10 @@ func (s *ChainSpec) Config(log *zap.Logger) (*ibc.ChainConfig, error) {
 		}
 	}
 
+	if len(s.ExposeAdditionalPorts) > 0 {
+		s.ChainConfig.ExposeAdditionalPorts = append(s.ChainConfig.ExposeAdditionalPorts, s.ExposeAdditionalPorts...)
+	}
+
 	// s.Name and chainConfig.Name are interchangeable
 	if s.Name == "" && s.ChainConfig.Name != "" {
 		s.Name = s.ChainConfig.Name

examples/cosmos/ethermint_test.go

@@ -1,7 +1,11 @@
 package cosmos_test
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
+	"io"
+	"net/http"
 	"testing"
 	"time"
 
@@ -11,6 +15,7 @@ import (
 	"github.com/strangelove-ventures/interchaintest/v8"
 	"github.com/strangelove-ventures/interchaintest/v8/chain/cosmos"
 	"github.com/strangelove-ventures/interchaintest/v8/ibc"
+	"github.com/strangelove-ventures/interchaintest/v8/testutil"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/zap/zaptest"
 )
@@ -27,9 +32,6 @@ func TestEthermintChain(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	numVals := 1
-	numFullNodes := 0
-
 	cosmos.SetSDKConfig(wallet)
 
 	genesis := []cosmos.GenesisKV{
@@ -83,6 +85,11 @@ func TestEthermintChain(t *testing.T) {
 		}),
 	}
 
+	jsonRpcOverrides := make(testutil.Toml)
+	jsonRpcOverrides["address"] = "0.0.0.0:8545"
+	appTomlOverrides := make(testutil.Toml)
+	appTomlOverrides["json-rpc"] = jsonRpcOverrides
+
 	decimals := int64(decimals)
 	cf := interchaintest.NewBuiltinChainFactory(zaptest.NewLogger(t), []*interchaintest.ChainSpec{
 		{
@@ -100,9 +107,10 @@ func TestEthermintChain(t *testing.T) {
 				TrustingPeriod: "168h0m0s",
 				ModifyGenesis:  cosmos.ModifyGenesis(genesis),
 				CoinDecimals:   &decimals,
+				// open the port for the EVM on all nodes
+				ExposeAdditionalPorts: []string{"8545/tcp"},
+				ConfigFileOverrides:   map[string]any{"config/app.toml": appTomlOverrides},
 			},
-			NumValidators: &numVals,
-			NumFullNodes:  &numFullNodes,
 		},
 	})
 
@@ -133,6 +141,28 @@ func TestEthermintChain(t *testing.T) {
 	balance, err := chain.GetNode().Chain.GetBalance(ctx, user.FormattedAddress(), denom)
 	require.NoError(t, err)
 	require.Equal(t, "10000000000", balance.String())
+
+	// verify access to port exposed via ExposeAdditionalPorts
+	evmJsonRpcUrl, err := chain.FullNodes[0].GetHostAddress(ctx, "8545/tcp")
+	require.NoError(t, err)
+
+	data := []byte(`{"jsonrpc":"2.0","id":1,"method":"eth_getBlockByNumber","params":["0x1", null]}`)
+	resp, err := http.Post(evmJsonRpcUrl, "application/json", bytes.NewBuffer(data))
+	require.NoError(t, err)
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	require.NoError(t, err)
+
+	response := struct {
+		Result struct {
+			Number string `json:"number"`
+		} `json:"result"`
+	}{}
+	err = json.Unmarshal(body, &response)
+	require.NoError(t, err)
+
+	require.Equal(t, "0x1", response.Result.Number)
 }
 
 type evmEpoch struct {

ibc/types.go

@@ -67,6 +67,9 @@ type ChainConfig struct {
 	// HostPortOverride exposes ports to the host.
 	// To avoid port binding conflicts, ports are only exposed on the 0th validator.
 	HostPortOverride map[int]int `yaml:"host-port-override"`
+	// ExposeAdditionalPorts exposes each port id to the host on a random port. ex: "8080/tcp"
+	// Access the address with ChainNode.GetHostAddress
+	ExposeAdditionalPorts []string
 	// Additional start command arguments
 	AdditionalStartArgs []string
 	// Environment variables for chain nodes
@@ -84,6 +87,10 @@ func (c ChainConfig) Clone() ChainConfig {
 	copy(sidecars, c.SidecarConfigs)
 	x.SidecarConfigs = sidecars
 
+	additionalPorts := make([]string, len(c.ExposeAdditionalPorts))
+	copy(additionalPorts, c.ExposeAdditionalPorts)
+	x.ExposeAdditionalPorts = additionalPorts
+
 	if c.CoinDecimals != nil {
 		coinDecimals := *c.CoinDecimals
 		x.CoinDecimals = &coinDecimals
@@ -206,6 +213,10 @@ func (c ChainConfig) MergeChainSpecConfig(other ChainConfig) ChainConfig {
 		c.Env = append(c.Env, other.Env...)
 	}
 
+	if len(other.ExposeAdditionalPorts) > 0 {
+		c.ExposeAdditionalPorts = append(c.ExposeAdditionalPorts, other.ExposeAdditionalPorts...)
+	}
+
 	return c
 }