chore: Connect the Claude Code desktop app to Codespaces (no-changelog) (#39524)

Co-authored-by: Claude Opus 5.5 <[email protected]>

scripts/cloud-session-ssh-config.mjs

@@ -0,0 +1,46 @@
+// Writes an OpenSSH host entry for the session Codespace, so tools that use the
+// system ssh (the Claude Code desktop app, VS Code Remote-SSH, plain `ssh`) can
+// connect by a fixed name.
+import { existsSync, mkdirSync, readFileSync, writeFileSync } from 'node:fs';
+import { homedir } from 'node:os';
+import { join } from 'node:path';
+
+export const HOST_ALIAS = 'n8n-codespace';
+const HOST_FILE = `${HOST_ALIAS}.conf`;
+const INCLUDE_LINE = `Include ~/.ssh/${HOST_FILE}`;
+
+/**
+ * Replaces the host name in `gh codespace ssh --config` output with a fixed alias.
+ * gh names the host `cs.<codespace>.<branch>`, so its name changes when the
+ * checkout changes branch. A saved connection must not depend on that.
+ */
+export function aliasHostConfig(ghConfig, alias = HOST_ALIAS) {
+	const hosts = ghConfig.match(/^Host .*$/gm) ?? [];
+	if (hosts.length !== 1 || !/^\s*ProxyCommand /m.test(ghConfig)) {
+		throw new Error(`Expected one host entry from gh codespace ssh --config, got ${hosts.length}`);
+	}
+	return ghConfig.replace(/^Host .*$/m, `Host ${alias}`).trimEnd() + '\n';
+}
+
+/**
+ * Returns the ssh config with the Include line at the top, or undefined if the line
+ * is already there. An Include after a Host block applies only to that block.
+ */
+export function withInclude(sshConfig, includeLine = INCLUDE_LINE) {
+	if (sshConfig.split('\n').some((line) => line.trim() === includeLine)) return undefined;
+	return `${includeLine}\n${sshConfig.length ? '\n' : ''}${sshConfig}`;
+}
+
+export function writeSshConfig(ghConfig, sshDir = join(homedir(), '.ssh')) {
+	mkdirSync(sshDir, { recursive: true, mode: 0o700 });
+
+	const hostPath = join(sshDir, HOST_FILE);
+	writeFileSync(hostPath, aliasHostConfig(ghConfig), { mode: 0o600 });
+
+	const configPath = join(sshDir, 'config');
+	const current = existsSync(configPath) ? readFileSync(configPath, 'utf8') : '';
+	const updated = withInclude(current);
+	// The mode applies only when the file is new. An existing file keeps its mode.
+	if (updated !== undefined) writeFileSync(configPath, updated, { mode: 0o600 });
+	return { hostPath, configPath, includeAdded: updated !== undefined };
+}

scripts/cloud-session.mjs

@@ -9,6 +9,7 @@
 //   pnpm session:opencode [name]   connect a local OpenCode client
 //   pnpm session ls                list Codespaces and tmux sessions
 //   pnpm session tunnel [port…]    forward ports to localhost
+//   pnpm session ssh-config        add an `n8n-codespace` host to ~/.ssh/config
 //   pnpm session stop              stop the Codespace
 //   pnpm session rm                delete the Codespace
 import { execFileSync, spawnSync } from 'node:child_process';
@@ -21,7 +22,10 @@ const DEVCONTAINER = '.devcontainer/codespaces/devcontainer.json';
 const MACHINE = 'premiumLinux';
 
 const gh = (...args) => execFileSync('gh', args, { encoding: 'utf8' }).trim();
-const ghTty = (...args) => spawnSync('gh', args, { stdio: 'inherit' });
+// On a TTY, gh queries the terminal background colour. The reply can reach the
+// shell (or the remote session) as text. A fixed GLAMOUR_STYLE skips the query.
+const ghTty = (...args) =>
+	spawnSync('gh', args, { stdio: 'inherit', env: { ...process.env, GLAMOUR_STYLE: 'dark' } });
 
 // Check the remote terminal database before tmux starts. Older images can lack
 // terminal definitions such as xterm-ghostty.
@@ -216,6 +220,25 @@ switch (cmd) {
 		process.exitCode = status ?? 1;
 		break;
 	}
+	case 'ssh-config': {
+		const name = ensureCodespace();
+		// A first connection starts a stopped codespace and creates gh's automatic
+		// key pair. The generated config names that key.
+		const { status } = ghTty('codespace', 'ssh', '-c', name, '--', 'true');
+		if (status !== 0) {
+			console.error(`Could not connect to ${name} over ssh.`);
+			process.exit(status ?? 1);
+		}
+		const { writeSshConfig, HOST_ALIAS } = await import('./cloud-session-ssh-config.mjs');
+		const { hostPath, configPath, includeAdded } = writeSshConfig(
+			gh('codespace', 'ssh', '--config', '-c', name),
+		);
+		console.log(`Wrote ${hostPath}${includeAdded ? ` and included it from ${configPath}` : ''}.`);
+		console.log(`Connect with \`ssh ${HOST_ALIAS}\`, or add the SSH host \`${HOST_ALIAS}\` in the`);
+		console.log('Claude Code desktop app and open /workspaces/n8n.');
+		console.log('Run this command again after you recreate the codespace.');
+		break;
+	}
 	case 'stop':
 	case 'rm': {
 		const cs = findCodespace();