Merge pull request #1 from dgageot/gateway

Add the gateway code

Author: rumpl

README.md

@@ -3,7 +3,7 @@
 Requirements:
 
 - A recent compose version (build from main)
-- Yhe gateway (https://github.com/docker/dgagateway)
+- The gateway (./dgagateway)
 - A recent Docker Desktop
 
 Then you can run:

gateway/.dockerignore

@@ -0,0 +1,5 @@
+*
+!/cmd
+!/vendor
+!/go.mod
+!/go.sum

gateway/.gitignore

@@ -0,0 +1 @@
+/docker-mcpgateway

gateway/Dockerfile

@@ -0,0 +1,15 @@
+# syntax=docker/dockerfile:1
+
+FROM golang:1.24-alpine3.21@sha256:ef18ee7117463ac1055f5a370ed18b8750f01589f13ea0b48642f5792b234044 AS build
+WORKDIR /app
+RUN --mount=type=cache,target=/root/.cache/go-build \
+    --mount=source=.,target=. \
+    go build -o / ./cmd/agent/ ./cmd/agents_gateway/
+
+FROM scratch AS agent
+ENTRYPOINT ["/agent"]
+COPY --from=build /agent /
+
+FROM scratch AS agents_gateway
+ENTRYPOINT ["/agents_gateway"]
+COPY --from=build /agents_gateway /

gateway/README.md

@@ -0,0 +1,29 @@
+## How to get it running?
+
+Build the `docker/mcpgateway` image:
+
+```console
+task build-gateway-image
+```
+
+Build the `docker-mcp` compose provider and install it as a cli plugin.
+
+```console
+task build-compose-provider
+```
+
+Manually build the latest version of [docker-compose](https://github.com/docker/compose)
+and install it as a cli plugin.
+
+Run the whole stack:
+
+```console
+docker compose up --build
+docker compose down --remove-orphans
+```
+
+## Do it with a single command
+
+```console
+task
+```

gateway/Taskfile.yml

@@ -0,0 +1,33 @@
+version: "3"
+
+tasks:
+  default:
+    desc: Build and run the Docker image
+    cmds:
+      - task: build
+      - task: down
+      - task: up
+
+  up:
+    desc: Start the demo Compose Stack
+    cmd: docker compose up --build
+
+  down:
+    desc: Stop the demo Compose Stack
+    cmd: docker compose down --remove-orphans
+
+  build-gateway-image:
+    desc: Build the gateway docker image
+    cmd: docker build -t docker/agents_gateway --target=agents_gateway .
+
+  build-compose-provider:
+    desc: Build the compose provider
+    cmds:
+      - go build -o docker-mcpgateway ./cmd/gateway_light_provider
+      - /bin/ln -sf "{{.TASKFILE_DIR}}/docker-mcpgateway" "{{.HOME}}/.docker/cli-plugins/docker-mcpgateway"
+
+  build:
+    desc: Build everything
+    cmds:
+      - task: build-gateway-image
+      - task: build-compose-provider

gateway/cmd/agent/main.go

@@ -0,0 +1,171 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/mark3labs/mcp-go/client"
+	"github.com/mark3labs/mcp-go/mcp"
+)
+
+func main() {
+	args := os.Args[1:]
+	if len(args) == 0 {
+		usage()
+		return
+	}
+
+	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer cancel()
+
+	switch args[0] {
+	case "list":
+		verbose := true
+		if err := list(ctx, verbose); err != nil {
+			log.Fatal(err)
+		}
+	case "count":
+		verbose := false
+		if err := list(ctx, verbose); err != nil {
+			log.Fatal(err)
+		}
+	case "call":
+		if err := call(ctx, args[1:]); err != nil {
+			log.Fatal(err)
+		}
+	default:
+		usage()
+	}
+}
+
+func usage() {
+	fmt.Println("Usage: client COMMAND [ARGS]")
+	fmt.Println()
+	fmt.Println("A command-line debug client for the MCP.")
+	fmt.Println()
+	fmt.Println("Commands:")
+	fmt.Println("  list     List all available tools")
+	fmt.Println("  count    Count all available tools")
+	fmt.Println("  call     Call a specific tool with arguments")
+}
+
+func list(ctx context.Context, verbose bool) error {
+	c, err := start(ctx)
+	if err != nil {
+		return fmt.Errorf("starting client: %w", err)
+	}
+	defer c.Close()
+
+	response, err := c.ListTools(ctx, mcp.ListToolsRequest{})
+	if err != nil {
+		return fmt.Errorf("listing tools: %w", err)
+	}
+
+	buf, err := json.MarshalIndent(response.Tools, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshalling tools: %w", err)
+	}
+
+	if verbose {
+		fmt.Println(len(response.Tools), "tools:")
+		fmt.Println(string(buf))
+	} else {
+		fmt.Println(len(response.Tools), "tools")
+	}
+
+	return nil
+}
+
+func call(ctx context.Context, args []string) error {
+	if len(args) == 0 {
+		return fmt.Errorf("no tool name provided")
+	}
+	toolName := args[0]
+
+	c, err := start(ctx)
+	if err != nil {
+		return fmt.Errorf("starting client: %w", err)
+	}
+	defer c.Close()
+
+	request := mcp.CallToolRequest{}
+	request.Params.Name = toolName
+	request.Params.Arguments = parseArgs(args[1:])
+
+	start := time.Now()
+	response, err := c.CallTool(ctx, request)
+	if err != nil {
+		return fmt.Errorf("calling tool: %w", err)
+	}
+	fmt.Println("Tool call took:", time.Since(start))
+
+	if response.IsError {
+		return fmt.Errorf("error calling tool: %s", toolName)
+	}
+
+	for _, content := range response.Content {
+		if textContent, ok := content.(mcp.TextContent); ok {
+			fmt.Println(textContent.Text)
+		} else {
+			fmt.Println(content)
+		}
+	}
+
+	return nil
+}
+
+func start(ctx context.Context) (*client.Client, error) {
+	host := os.Getenv("MCPGATEWAY_ENDPOINT")
+	c, err := client.NewSSEMCPClient("http://" + host + "/sse")
+	if err != nil {
+		return nil, err
+	}
+
+	if err := c.Start(ctx); err != nil {
+		return nil, err
+	}
+
+	initRequest := mcp.InitializeRequest{}
+	initRequest.Params.ProtocolVersion = mcp.LATEST_PROTOCOL_VERSION
+	initRequest.Params.ClientInfo = mcp.Implementation{
+		Name:    "docker",
+		Version: "1.0.0",
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, 20*time.Second)
+	defer cancel()
+
+	if _, err := c.Initialize(ctx, initRequest); err != nil {
+		return nil, fmt.Errorf("initializing: %w", err)
+	}
+
+	return c, nil
+}
+
+func parseArgs(args []string) map[string]any {
+	parsed := map[string]any{}
+
+	for _, arg := range args {
+		parts := strings.SplitN(arg, "=", 2)
+		if len(parts) == 2 {
+			parsed[parts[0]] = parts[1]
+		} else {
+			parsed[arg] = nil
+		}
+	}
+
+	// MCP servers return an error if the args are empty so we make sure
+	// there is at least one argument
+	if len(parsed) == 0 {
+		parsed["args"] = "..."
+	}
+
+	return parsed
+}