rewrote ssh handling to make it clearer

pkg/commands/docker.go

@@ -72,26 +72,26 @@ func (c *DockerCommand) NewCommandObject(obj CommandObject) CommandObject {
 }
 
 // NewDockerCommand creates a DockerCommand struct that wraps the docker client.
-// Able to run docker commands. And handles SSH docker hosts
+// Able to run docker commands and handles SSH docker hosts
 func NewDockerCommand(log *logrus.Entry, osCommand *OSCommand, tr *i18n.TranslationSet, config *config.AppConfig, errorChan chan error) (*DockerCommand, error) {
 	dockerHost, err := determineDockerHost()
 	if err != nil {
 		ogLog.Printf("> could not determine host %v", err)
 	}
 
-	tunnelCloser, err := ssh.NewSSHHandler(osCommand).HandleSSHDockerHost(dockerHost)
+	tunnelResult, err := ssh.NewSSHHandler(osCommand).HandleSSHDockerHost(dockerHost)
 	if err != nil {
 		ogLog.Fatal(err)
 	}
+	// If we created a tunnel to the remote ssh host, we then override the dockerhost to point to the tunnel
+	if tunnelResult.Created {
+		dockerHost = tunnelResult.SocketPath
+	}
 
 	clientOpts := []client.Opt{
-		client.FromEnv,
+		client.WithTLSClientConfigFromEnv(),
 		client.WithVersion(APIVersion),
-	}
-	// For an ssh connection the DOCKER_HOST env variable has been overridden.
-	// Discard the previously determined dockerHost
-	if !strings.HasPrefix(dockerHost, "ssh://") {
-		clientOpts = append(clientOpts, client.WithHost(dockerHost))
+		client.WithHost(dockerHost),
 	}
 
 	cli, err := client.NewClientWithOpts(clientOpts...)
@@ -107,7 +107,7 @@ func NewDockerCommand(log *logrus.Entry, osCommand *OSCommand, tr *i18n.Translat
 		Client:                 cli,
 		ErrorChan:              errorChan,
 		InDockerComposeProject: true,
-		Closers:                []io.Closer{tunnelCloser},
+		Closers:                []io.Closer{tunnelResult.Closer},
 	}
 
 	dockerCommand.setDockerComposeCommand(config)

pkg/commands/ssh/ssh.go

@@ -42,32 +42,36 @@ func NewSSHHandler(oSCommand CmdKiller) *SSHHandler {
 	}
 }
 
+type TunnelResult struct {
+	Closer     io.Closer
+	SocketPath string
+	Created    bool
+}
+
 // HandleSSHDockerHost overrides the DOCKER_HOST environment variable
 // to point towards a local unix socket tunneled over SSH to the specified ssh host.
-func (self *SSHHandler) HandleSSHDockerHost(dockerHost string) (io.Closer, error) {
-	const key = "DOCKER_HOST"
-	ctx := context.Background()
-
+func (self *SSHHandler) HandleSSHDockerHost(dockerHost string) (TunnelResult, error) {
 	u, err := url.Parse(dockerHost)
 	if err != nil {
 		// if no or an invalid docker host is specified, continue nominally
-		return noopCloser{}, nil
+		return TunnelResult{Closer: noopCloser{}}, nil
 	}
 
 	// if the docker host scheme is "ssh", forward the docker socket before creating the client
 	if u.Scheme == "ssh" {
+		ctx := context.Background()
 		tunnel, err := self.createDockerHostTunnel(ctx, u.String())
 		if err != nil {
-			return noopCloser{}, fmt.Errorf("tunnel ssh docker host: %w", err)
-		}
-		err = self.setenv(key, tunnel.socketPath)
-		if err != nil {
-			return noopCloser{}, fmt.Errorf("override DOCKER_HOST to tunneled socket: %w", err)
+			return TunnelResult{Closer: noopCloser{}}, fmt.Errorf("tunnel ssh docker host: %w", err)
 		}
 
-		return tunnel, nil
+		return TunnelResult{
+			Closer:     tunnel,
+			SocketPath: tunnel.socketPath,
+			Created:    true,
+		}, nil
 	}
-	return noopCloser{}, nil
+	return TunnelResult{Closer: noopCloser{}}, nil
 }
 
 type noopCloser struct{}