feat: "exec" command to start processes inside remote containers (#139)

pkg/api/client.go

@@ -28,6 +28,7 @@ type ContainerClient interface {
 	RemoveContainer(ctx context.Context, serviceNameOrID, containerNameOrID string, opts container.RemoveOptions) error
 	StartContainer(ctx context.Context, serviceNameOrID, containerNameOrID string) error
 	StopContainer(ctx context.Context, serviceNameOrID, containerNameOrID string, opts container.StopOptions) error
+	ExecContainer(ctx context.Context, serviceNameOrID, containerNameOrID string, config ExecOptions) (int, error)
 }
 
 type DNSClient interface {

pkg/api/container_exec.go

@@ -0,0 +1,37 @@
+package api
+
+import "io"
+
+// ExecOptions contains configuration for executing a command in a container.
+type ExecOptions struct {
+	// Command is the command to run in the container.
+	Command []string
+	// AttachStdin attaches the stdin stream to the exec session.
+	AttachStdin bool
+	// AttachStdout attaches the stdout stream to the exec session.
+	AttachStdout bool
+	// AttachStderr attaches the stderr stream to the exec session.
+	AttachStderr bool
+	// Tty allocates a pseudo-TTY for the exec session.
+	Tty bool
+	// Detach runs the command in the background without attaching to streams.
+	Detach bool
+
+	//// Not yet implemented fields
+	// User specifies the user to run the command as.
+	User string
+	// Privileged runs the command in privileged mode.
+	Privileged bool
+	// WorkingDir sets the working directory for the command.
+	WorkingDir string
+	// Env sets environment variables for the command.
+	Env []string
+
+	// Client-side only fields (not serialized, not sent to server)
+	// Stdin is the input stream. Defaults to os.Stdin if nil.
+	Stdin io.Reader `json:"-"`
+	// Stdout is the output stream. Defaults to os.Stdout if nil.
+	Stdout io.Writer `json:"-"`
+	// Stderr is the error stream. Defaults to os.Stderr if nil.
+	Stderr io.Writer `json:"-"`
+}

pkg/client/container.go

@@ -299,3 +299,49 @@ func (cli *Client) RemoveContainer(
 
 	return nil
 }
+
+// ExecContainer executes a command in a container within the service.
+// If containerNameOrID is empty, the first container in the service will be used.
+func (cli *Client) ExecContainer(
+	ctx context.Context, serviceNameOrID, containerNameOrID string, execOpts api.ExecOptions,
+) (int, error) {
+	var ctr api.MachineServiceContainer
+
+	if containerNameOrID == "" {
+		// Find the first (random) container in the service
+		service, err := cli.InspectService(ctx, serviceNameOrID)
+		if err != nil {
+			return -1, fmt.Errorf("inspect service: %w", err)
+		}
+		if len(service.Containers) == 0 {
+			return -1, fmt.Errorf("no containers found in service %s", serviceNameOrID)
+		}
+		ctr = service.Containers[0]
+	} else {
+		// Find the specific container
+		var err error
+		ctr, err = cli.InspectContainer(ctx, serviceNameOrID, containerNameOrID)
+		if err != nil {
+			return -1, fmt.Errorf("inspect container: %w", err)
+		}
+	}
+
+	machine, err := cli.InspectMachine(ctx, ctr.MachineID)
+	if err != nil {
+		return -1, fmt.Errorf("inspect machine '%s': %w", ctr.MachineID, err)
+	}
+
+	// Proxy Docker gRPC requests to the machine hosting the container
+	ctx = proxyToMachine(ctx, machine.Machine)
+
+	// Execute the command in the container
+	exitCode, err := cli.Docker.ExecContainer(ctx, machinedocker.ExecConfig{
+		ContainerID: ctr.Container.ID,
+		Options:     execOpts,
+	})
+	if err != nil {
+		return exitCode, fmt.Errorf("exec in container %s: %w", ctr.Container.Name, err)
+	}
+
+	return exitCode, nil
+}