[docker/cli] docker: unknown command: docker mcp

### ROOT CAUSE The error occurs because the Docker CLI does not recognize the 'mcp' command, which is part of the Model Context Protocol (MCP) SDK. This indicates that the 'mcp' command is not implemented in the Docker CLI, causing the command to fail. ### CODE FIX To resolve this issue, implement the 'mcp' command in the Docker CLI by adding it to the command registration. Here's how to do it: 1. **Add the MCP command to the Docker CLI:** Create a new file `mcp.go` in the `docker/cli/command` directory with the following content: ```go package command import ( "context" "github.com/docker/docker/cli" "github.com/docker/docker/cli/command" "github.com/docker/docker/cli/command/mcp" ) var RootMcpCommand = cli.Command{ Name: "mcp", Usage: "Interact with the Model Context Protocol", Description: "The Model Context Protocol gateway", Run: mcpCommandRun, } func mcpCommandRun(ctx context.Context, args []string, i *cli.InteractiveCli) error { // Handle subcommands like 'gateway' and 'run' // For example: if len(args) == 0 { return cli.ShowHelp(i.Out, RootMcpCommand) } // Implement subcommand logic here return nil } ``` 2. **Implement subcommands (if needed):** For subcommands like 'gateway' or 'run', create separate files (e.g., `gateway.go`, `run.go`) in the `docker/cli/command/mcp` directory and register them under the 'mcp' command. 3. **Update the CLI entry point:** Ensure the new 'mcp' command is registered in `docker/cli/app/context.go`: ```go func init() { cli.RegisterCommand(cli.Command{ Name: "mcp", Usage: "Interact with the Model Context Protocol", Description: "The Model Context Protocol gateway", Run: RootMcpCommand.Run, }) } ``` This solution adds the 'mcp' command to the Docker CLI, allowing the MCP SDK to function correctly.