feat(mcpgateway): add MCP gateway module (#3232)

Author: mdelapenya

.github/dependabot.yml

@@ -29,6 +29,7 @@ updates:
         - /modules/couchbase
         - /modules/databend
         - /modules/dind
+        - /modules/dockermcpgateway
         - /modules/dockermodelrunner
         - /modules/dolt
         - /modules/dynamodb

.vscode/.testcontainers-go.code-workspace

@@ -65,6 +65,10 @@
             "name": "module / dind",
             "path": "../modules/dind"
         },
+        {
+            "name": "module / dockermcpgateway",
+            "path": "../modules/dockermcpgateway"
+        },
         {
             "name": "module / dockermodelrunner",
             "path": "../modules/dockermodelrunner"

docs/modules/dockermcpgateway.md

@@ -0,0 +1,108 @@
+# Docker MCP Gateway
+
+Not available until the next release <a href="https://github.com/testcontainers/testcontainers-go"><span class="tc-version">:material-tag: main</span></a>
+
+## Introduction
+
+The Testcontainers module for the Docker MCP Gateway.
+
+## Adding this module to your project dependencies
+
+Please run the following command to add the Docker MCP Gateway module to your Go dependencies:
+
+```
+go get github.com/testcontainers/testcontainers-go/modules/dockermcpgateway
+```
+
+## Usage example
+
+<!--codeinclude-->
+[Creating a DockerMCPGateway container](../../modules/dockermcpgateway/examples_test.go) inside_block:run_mcp_gateway
+<!--/codeinclude-->
+
+## Module Reference
+
+### Run function
+
+- Not available until the next release <a href="https://github.com/testcontainers/testcontainers-go"><span class="tc-version">:material-tag: main</span></a>
+
+The DockerMCPGateway module exposes one entrypoint function to create the DockerMCPGateway container, and this function receives three parameters:
+
+```golang
+func Run(ctx context.Context, img string, opts ...testcontainers.ContainerCustomizer) (*Container, error)
+```
+
+- `context.Context`, the Go context.
+- `string`, the Docker image to use.
+- `testcontainers.ContainerCustomizer`, a variadic argument for passing options.
+
+#### Image
+
+Use the second argument in the `Run` function to set a valid Docker image.
+In example: `Run(context.Background(), "docker/mcp-gateway:latest")`.
+
+### Container Options
+
+When starting the DockerMCPGateway container, you can pass options in a variadic way to configure it.
+
+{% include "../features/common_functional_options_list.md" %}
+
+#### WithTools
+
+- Not available until the next release <a href="https://github.com/testcontainers/testcontainers-go"><span class="tc-version">:material-tag: main</span></a>
+
+Use the `WithTools` option to set the tools from a server to be available in the MCP Gateway container. Adding multiple tools for the same server will append to the existing tools for that server, and no duplicate tools will be added for the same server.
+
+```golang
+dockermcpgateway.WithTools("brave", []string{"brave_local_search", "brave_web_search"})
+```
+
+#### WithSecrets
+
+- Not available until the next release <a href="https://github.com/testcontainers/testcontainers-go"><span class="tc-version">:material-tag: main</span></a>
+
+Use the `WithSecrets` option to set the tools from a server to be available in the MCP Gateway container. Empty keys are not allowed, although empty values are allowed for a key.
+
+```golang
+dockermcpgateway.WithSecret("github_token", "test_value")
+dockermcpgateway.WithSecrets(map[string]{
+    "github_token": "test_value",
+    "foo":          "bar",
+})
+```
+
+### Container Methods
+
+The DockerMCPGateway container exposes the following methods:
+
+#### Tools
+
+- Not available until the next release <a href="https://github.com/testcontainers/testcontainers-go"><span class="tc-version">:material-tag: main</span></a>
+
+Returns a map of tools available in the MCP Gateway container, where the key is the server name and the value is a slice of tool names.
+
+```golang
+tools := ctr.Tools()
+```
+
+#### GatewayEndpoint
+
+- Not available until the next release <a href="https://github.com/testcontainers/testcontainers-go"><span class="tc-version">:material-tag: main</span></a>
+
+Returns the endpoint of the MCP Gateway container, which is a string containing the host and mapped port for the default MCP Gateway port (8811/tcp).
+
+```golang
+endpoint := ctr.GatewayEndpoint()
+```
+### Examples
+
+#### Connecting to the MCP Gateway using an MCP client
+
+This example shows the usage of the MCP Gateway module to connect with an [MCP client](https://github.com/modelcontextprotocol/go-sdk).
+
+<!--codeinclude-->
+[Run the MCP Gateway](../../modules/dockermcpgateway/examples_test.go) inside_block:run_mcp_gateway
+[Get MCP Gateway's endpoint](../../modules/dockermcpgateway/examples_test.go) inside_block:get_gateway
+[Connect with an MCP client](../../modules/dockermcpgateway/examples_test.go) inside_block:connect_mcp_client
+[List tools](../../modules/dockermcpgateway/examples_test.go) inside_block:list_tools
+<!--/codeinclude-->

mkdocs.yml

@@ -80,6 +80,7 @@ nav:
         - modules/couchbase.md
         - modules/databend.md
         - modules/dind.md
+        - modules/dockermcpgateway.md
         - modules/dockermodelrunner.md
         - modules/dolt.md
         - modules/dynamodb.md

modules/dockermcpgateway/Makefile

@@ -0,0 +1,5 @@
+include ../../commons-test.mk
+
+.PHONY: test
+test:
+	$(MAKE) test-dockermcpgateway

modules/dockermcpgateway/dockermcpgateway.go

@@ -0,0 +1,108 @@
+package dockermcpgateway
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/docker/docker/api/types/container"
+
+	"github.com/testcontainers/testcontainers-go"
+	"github.com/testcontainers/testcontainers-go/internal/core"
+	"github.com/testcontainers/testcontainers-go/wait"
+)
+
+const (
+	defaultPort = "8811/tcp"
+	secretsPath = "/testcontainers/app/secrets"
+)
+
+// Container represents the DockerMCPGateway container type used in the module
+type Container struct {
+	testcontainers.Container
+	tools map[string][]string
+}
+
+// Run creates an instance of the DockerMCPGateway container type
+func Run(ctx context.Context, img string, opts ...testcontainers.ContainerCustomizer) (*Container, error) {
+	dockerHostMount := core.MustExtractDockerSocket(ctx)
+
+	moduleOpts := []testcontainers.ContainerCustomizer{
+		testcontainers.WithExposedPorts(defaultPort),
+		testcontainers.WithHostConfigModifier(func(hc *container.HostConfig) {
+			hc.Binds = []string{
+				dockerHostMount + ":/var/run/docker.sock",
+			}
+		}),
+		testcontainers.WithWaitStrategy(wait.ForAll(
+			wait.ForListeningPort(defaultPort),
+			wait.ForLog(".*Start sse server on port.*").AsRegexp(),
+		)),
+	}
+
+	settings := defaultOptions()
+	for _, opt := range opts {
+		if apply, ok := opt.(Option); ok {
+			if err := apply(&settings); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	cmds := []string{"--transport=sse"}
+	for server, tools := range settings.tools {
+		cmds = append(cmds, "--servers="+server)
+		for _, tool := range tools {
+			cmds = append(cmds, "--tools="+tool)
+		}
+	}
+	if len(settings.secrets) > 0 {
+		cmds = append(cmds, "--secrets="+secretsPath)
+
+		secretsContent := ""
+		for key, value := range settings.secrets {
+			secretsContent += key + "=" + value + "\n"
+		}
+
+		moduleOpts = append(moduleOpts, testcontainers.WithFiles(testcontainers.ContainerFile{
+			Reader:            strings.NewReader(secretsContent),
+			ContainerFilePath: secretsPath,
+			FileMode:          0o644,
+		}))
+	}
+
+	moduleOpts = append(moduleOpts, testcontainers.WithCmd(cmds...))
+
+	// append user-defined options
+	moduleOpts = append(moduleOpts, opts...)
+
+	container, err := testcontainers.Run(ctx, img, moduleOpts...)
+	var c *Container
+	if container != nil {
+		c = &Container{Container: container, tools: settings.tools}
+	}
+
+	if err != nil {
+		return c, fmt.Errorf("generic container: %w", err)
+	}
+
+	return c, nil
+}
+
+// GatewayEndpoint returns the endpoint for the DockerMCPGateway container.
+// It uses the mapped port for the default port (8811/tcp) and the "http" protocol.
+func (c *Container) GatewayEndpoint(ctx context.Context) (string, error) {
+	endpoint, err := c.PortEndpoint(ctx, defaultPort, "http")
+	if err != nil {
+		return "", fmt.Errorf("port endpoint: %w", err)
+	}
+
+	return endpoint, nil
+}
+
+// Tools returns the tools configured for the DockerMCPGateway container,
+// indexed by server name.
+// The keys are the server names and the values are slices of tool names.
+func (c *Container) Tools() map[string][]string {
+	return c.tools
+}

modules/dockermcpgateway/dockermcpgateway_test.go

@@ -0,0 +1,89 @@
+package dockermcpgateway_test
+
+import (
+	"context"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/testcontainers/testcontainers-go"
+	dmcpg "github.com/testcontainers/testcontainers-go/modules/dockermcpgateway"
+)
+
+func TestDockerMCPGateway(t *testing.T) {
+	ctx := context.Background()
+
+	ctr, err := dmcpg.Run(ctx, "docker/mcp-gateway:latest")
+	testcontainers.CleanupContainer(t, ctr)
+	require.NoError(t, err)
+
+	require.Empty(t, ctr.Tools())
+}
+
+func TestDockerMCPGateway_withServerAndTools(t *testing.T) {
+	ctx := context.Background()
+
+	ctr, err := dmcpg.Run(
+		ctx, "docker/mcp-gateway:latest",
+		dmcpg.WithTools("curl", []string{"curl"}),
+		dmcpg.WithTools("brave", []string{"brave_local_search", "brave_web_search"}),
+		dmcpg.WithTools("github-official", []string{"add_issue_comment"}),
+	)
+	testcontainers.CleanupContainer(t, ctr)
+	require.NoError(t, err)
+
+	require.Len(t, ctr.Tools(), 3)
+
+	for server, tools := range ctr.Tools() {
+		switch server {
+		case "curl":
+			require.Equal(t, []string{"curl"}, tools)
+		case "brave":
+			require.ElementsMatch(t, []string{"brave_local_search", "brave_web_search"}, tools)
+		case "github-official":
+			require.Equal(t, []string{"add_issue_comment"}, tools)
+		default:
+			t.Errorf("unexpected server: %s", server)
+		}
+	}
+}
+
+func TestDockerMCPGateway_withSecret(t *testing.T) {
+	ctx := context.Background()
+
+	ctr, err := dmcpg.Run(
+		ctx, "docker/mcp-gateway:latest",
+		dmcpg.WithSecret("github.personal_access_token", "test_token"),
+	)
+	testcontainers.CleanupContainer(t, ctr)
+	require.NoError(t, err)
+
+	r, err := ctr.CopyFileFromContainer(ctx, "/testcontainers/app/secrets")
+	require.NoError(t, err)
+
+	bytes, err := io.ReadAll(r)
+	require.NoError(t, err)
+	require.Equal(t, "github.personal_access_token=test_token\n", string(bytes))
+}
+
+func TestDockerMCPGateway_withSecrets(t *testing.T) {
+	ctx := context.Background()
+
+	ctr, err := dmcpg.Run(
+		ctx, "docker/mcp-gateway:latest",
+		dmcpg.WithSecrets(map[string]string{
+			"github.personal_access_token": "test_token",
+			"another.secret":               "another_value",
+		}),
+	)
+	testcontainers.CleanupContainer(t, ctr)
+	require.NoError(t, err)
+
+	r, err := ctr.CopyFileFromContainer(ctx, "/testcontainers/app/secrets")
+	require.NoError(t, err)
+
+	bytes, err := io.ReadAll(r)
+	require.NoError(t, err)
+	require.Equal(t, "github.personal_access_token=test_token\nanother.secret=another_value\n", string(bytes))
+}