feat: add --ssh-host-prefix flag to "coder ssh"

aaronlehmann · aaronlehmann · commit de8df0612acf · 2025-01-09T14:17:54.000-08:00
This adds a flag matching `--ssh-host-prefix` from `coder config-ssh` to
`coder ssh`. By trimming a custom prefix from the argument, we can set
up wildcard-based `Host` entries in SSH config for the IDE plugins (and
eventually `coder config-ssh`).

We also replace `--` in the argument with `/`, so ownership can be
specified in wildcard-based SSH hosts like `&lt;owner&gt;--&lt;workspace&gt;`.
diff --git a/cli/ssh.go b/cli/ssh.go
@@ -56,6 +56,7 @@ var (
 func (r *RootCmd) ssh() *serpent.Command {
 	var (
 		stdio            bool
+		hostPrefix       string
 		forwardAgent     bool
 		forwardGPG       bool
 		identityAgent    string
@@ -180,15 +181,9 @@ func (r *RootCmd) ssh() *serpent.Command {
 				parsedEnv = append(parsedEnv, [2]string{k, v})
 			}
 
-			namedWorkspace := inv.Args[0]
-			if parts := strings.Split(namedWorkspace, "--"); len(parts) >= 3 {
-				owner := parts[1]
-				name := parts[2]
-				namedWorkspace = owner + "/" + name
-				if len(parts) > 3 {
-					namedWorkspace += "." + parts[3]
-				}
-			}
+			namedWorkspace := strings.TrimPrefix(inv.Args[0], hostPrefix)
+			// Support "--" as a delimiter between owner and workspace name
+			namedWorkspace = strings.ReplaceAll(namedWorkspace, "--", "/")
 
 			workspace, workspaceAgent, err := getWorkspaceAndAgent(ctx, inv, client, !disableAutostart, namedWorkspace)
 			if err != nil {
@@ -487,6 +482,12 @@ func (r *RootCmd) ssh() *serpent.Command {
 			Description: "Specifies whether to emit SSH output over stdin/stdout.",
 			Value:       serpent.BoolOf(&stdio),
 		},
+		{
+			Flag:        "ssh-host-prefix",
+			Env:         "CODER_CONFIGSSH_SSH_HOST_PREFIX",
+			Description: "Strip this prefix from the provided hostname to determine the workspace name.",
+			Value:       serpent.StringOf(&hostPrefix),
+		},
 		{
 			Flag:          "forward-agent",
 			FlagShorthand: "A",
diff --git a/cli/ssh_test.go b/cli/ssh_test.go
@@ -1483,7 +1483,7 @@ func TestSSH(t *testing.T) {
 		}
 	})
 
-	t.Run("ParseHostname", func(t *testing.T) {
+	t.Run("SSHHostPrefix", func(t *testing.T) {
 		t.Parallel()
 		client, workspace, agentToken := setupWorkspaceForAgent(t)
 		_, _ = tGoContext(t, func(ctx context.Context) {
@@ -1507,7 +1507,7 @@ func TestSSH(t *testing.T) {
 		user, err := client.User(ctx, codersdk.Me)
 		require.NoError(t, err)
 
-		inv, root := clitest.New(t, "ssh", "--stdio", fmt.Sprintf("coder-vscode.coder.prod.netflix.net--%s--%s", user.Username, workspace.Name))
+		inv, root := clitest.New(t, "ssh", "--stdio", "--ssh-host-prefix", "coder.dummy.com--", fmt.Sprintf("coder.dummy.com--%s--%s", user.Username, workspace.Name))
 		clitest.SetupConfig(t, client, root)
 		inv.Stdin = clientOutput
 		inv.Stdout = serverInput
diff --git a/cli/testdata/coder_ssh_--help.golden b/cli/testdata/coder_ssh_--help.golden
@@ -39,6 +39,10 @@ OPTIONS:
   -R, --remote-forward string-array, $CODER_SSH_REMOTE_FORWARD
           Enable remote port forwarding (remote_port:local_address:local_port).
 
+      --ssh-host-prefix string, $CODER_CONFIGSSH_SSH_HOST_PREFIX
+          Strip this prefix from the provided hostname to determine the
+          workspace name.
+
       --stdio bool, $CODER_SSH_STDIO
           Specifies whether to emit SSH output over stdin/stdout.
 
diff --git a/docs/reference/cli/ssh.md b/docs/reference/cli/ssh.md
