feat(worker): exec-as-user, stdin input, chown + userns plumbing

apps/agent-worker/src/env.ts

@@ -37,6 +37,10 @@ export const env = {
     '',
   // How long a per-user box container survives with no active jobs/terminals.
   boxIdleMs: intEnv('SPOON_AGENT_BOX_IDLE_MS', 1_800_000),
+  // Override for the box container's --userns flag. Unset → keep-id mapping
+  // under podman (host user becomes the box user), nothing under docker.
+  // Empty string disables entirely; any other value passes through verbatim.
+  boxUserns: process.env.SPOON_AGENT_BOX_USERNS,
   // Dev-only: exit if the parent dev runner dies, so the worker never orphans
   // and holds port 3921 across restarts. Set by scripts/dev-agent-worker.
   devWatchdog: process.env.SPOON_AGENT_DEV_WATCHDOG === '1',

apps/agent-worker/src/runtime/docker.ts

@@ -5,6 +5,7 @@ import Docker from 'dockerode';
 import { execa } from 'execa';
 
 import { env } from '../env';
+import { BOX_UID, linuxUsername } from './box-user';
 
 type CommandResult = {
   exitCode: number;
@@ -26,6 +27,21 @@ const environmentArgs = (environment: Record<string, string>) =>
 
 const networkArgs = () => (env.network ? ['--network', env.network] : []);
 
+// Box user namespace mapping. Under rootless podman, keep-id maps the host
+// user onto the box user's uid so host-side writes (clones, dotfiles, file
+// editor) are already user-owned inside the box. Rootful docker has no
+// equivalent — ownership is repaired with targeted chowns instead (see
+// chownInBox). SPOON_AGENT_BOX_USERNS overrides: empty disables, any other
+// value passes through.
+export const boxUsernsArgs = (): string[] => {
+  if (env.boxUserns !== undefined) {
+    return env.boxUserns ? [`--userns=${env.boxUserns}`] : [];
+  }
+  return containerRuntime().endsWith('podman')
+    ? [`--userns=keep-id:uid=${BOX_UID},gid=${BOX_UID}`]
+    : [];
+};
+
 const containerRuntime = () => env.containerRuntime;
 
 // `docker run` reuses a stale local `:latest` forever, so without an explicit
@@ -173,6 +189,10 @@ export const ensureUserContainer = async (args: {
   username: string;
   workdir: string;
   containerHome: string;
+  // Runs once per fresh container, after `run` succeeds — box-user init
+  // (useradd, sudo policy, password) hooks in here so every creation path
+  // (acquire, explicit start) sets the user up without duplicating the logic.
+  onCreated?: (containerName: string) => Promise<void>;
 }): Promise<string> => {
   await ensureJobImagePulled();
   const name = userContainerName(args.username);
@@ -196,10 +216,13 @@ export const ensureUserContainer = async (args: {
       '--init',
       '--name',
       name,
+      '--hostname',
+      `${linuxUsername(args.username)}-box`,
       '--memory',
       '4g',
       '--cpus',
       '2',
+      ...boxUsernsArgs(),
       ...networkArgs(),
       '-v',
       jobWorkspaceVolumeSpec(args.workdir, args.containerHome),
@@ -211,6 +234,7 @@ export const ensureUserContainer = async (args: {
     ],
     { stdin: 'ignore' },
   );
+  if (args.onCreated) await args.onCreated(name);
   return name;
 };
 
@@ -236,7 +260,12 @@ export const inspectUserBoxStatus = async (
     { reject: false, stdin: 'ignore' },
   );
   if (result.exitCode !== 0) {
-    return { running: false, image: null, startedAt: null, memoryLimitBytes: null };
+    return {
+      running: false,
+      image: null,
+      startedAt: null,
+      memoryLimitBytes: null,
+    };
   }
   const [runningField, imageField, startedAtField, memoryField] = result.stdout
     .trim()
@@ -335,6 +364,25 @@ export const killBoxProcessesByMarker = async (args: {
   );
 };
 
+// Shared `<runtime> exec` argv. `user` runs the command as that container
+// user instead of root — terminals and agent turns pass the box user; init,
+// chown and kill paths stay root.
+export const execArgv = (args: {
+  containerName: string;
+  command: string[];
+  environment: Record<string, string>;
+  containerCwd: string;
+  user?: string;
+}): string[] => [
+  'exec',
+  ...environmentArgs(args.environment),
+  '-w',
+  args.containerCwd,
+  ...(args.user ? ['-u', args.user] : []),
+  args.containerName,
+  ...args.command,
+];
+
 export const streamExecInContainer = async (args: {
   containerName: string;
   command: string[];
@@ -342,21 +390,16 @@ export const streamExecInContainer = async (args: {
   containerCwd: string;
   redact: (value: string) => string;
   timeoutMs: number;
+  user?: string;
   onStdoutLine?: (line: string) => Promise<void>;
   onStderrLine?: (line: string) => Promise<void>;
 }): Promise<CommandResult> => {
-  const subprocess = execa(
-    containerRuntime(),
-    [
-      'exec',
-      ...environmentArgs(args.environment),
-      '-w',
-      args.containerCwd,
-      args.containerName,
-      ...args.command,
-    ],
-    { all: true, reject: false, stdin: 'ignore', timeout: args.timeoutMs },
-  );
+  const subprocess = execa(containerRuntime(), execArgv(args), {
+    all: true,
+    reject: false,
+    stdin: 'ignore',
+    timeout: args.timeoutMs,
+  });
   return streamSubprocess(
     subprocess,
     args.redact,
@@ -372,20 +415,50 @@ export const runExecInContainer = async (args: {
   containerCwd: string;
   redact: (value: string) => string;
   timeoutMs: number;
+  user?: string;
+  // Piped to the command's stdin (e.g. `chpasswd` credentials, which must
+  // never appear in argv). Without it stdin is closed.
+  input?: string;
 }): Promise<CommandResult> => {
+  const result = await execa(containerRuntime(), execArgv(args), {
+    all: true,
+    reject: false,
+    timeout: args.timeoutMs,
+    ...(args.input == null
+      ? { stdin: 'ignore' as const }
+      : { input: args.input }),
+  });
+  return normalizeRunResult(result, result.all, args.redact);
+};
+
+// Best-effort ownership repair after host-side writes into a box home. Under
+// dev podman (keep-id) this is a no-op — files are already the box uid; under
+// prod docker it fixes uid-0 ownership left by the worker container. Failures
+// are logged, not thrown: a stopped box just means the next creation's
+// marker-guarded chown (or the next call) picks it up.
+export const chownInBox = async (args: {
+  containerName: string;
+  paths: string[];
+}): Promise<void> => {
+  if (args.paths.length === 0) return;
   const result = await execa(
     containerRuntime(),
     [
       'exec',
-      ...environmentArgs(args.environment),
-      '-w',
-      args.containerCwd,
       args.containerName,
-      ...args.command,
+      'chown',
+      '-R',
+      `${BOX_UID}:${BOX_UID}`,
+      ...args.paths,
     ],
-    { all: true, reject: false, stdin: 'ignore', timeout: args.timeoutMs },
+    { all: true, reject: false, stdin: 'ignore' },
   );
-  return normalizeRunResult(result, result.all, args.redact);
+  const normalized = normalizeRunResult(result, result.all, (value) => value);
+  if (normalized.exitCode !== 0) {
+    console.error(
+      `chown in ${args.containerName} failed (${String(normalized.exitCode)}): ${normalized.output}`,
+    );
+  }
 };
 
 export const stopWorkspaceContainer = async (containerName: string) => {

apps/agent-worker/tests/unit/docker-runtime.test.ts

@@ -44,6 +44,65 @@ describe('Docker runtime', () => {
     );
   });
 
+  test('boxUsernsArgs maps the host user onto the box uid under podman', async () => {
+    process.env.SPOON_AGENT_CONTAINER_RUNTIME = 'podman';
+    const { boxUsernsArgs } = await loadVolumeSpec();
+    expect(boxUsernsArgs()).toEqual(['--userns=keep-id:uid=1000,gid=1000']);
+  });
+
+  test('boxUsernsArgs adds nothing under docker', async () => {
+    process.env.SPOON_AGENT_CONTAINER_RUNTIME = 'docker';
+    const { boxUsernsArgs } = await loadVolumeSpec();
+    expect(boxUsernsArgs()).toEqual([]);
+  });
+
+  test('SPOON_AGENT_BOX_USERNS overrides: value passes through, empty disables', async () => {
+    process.env.SPOON_AGENT_CONTAINER_RUNTIME = 'podman';
+    process.env.SPOON_AGENT_BOX_USERNS = 'host';
+    let { boxUsernsArgs } = await loadVolumeSpec();
+    expect(boxUsernsArgs()).toEqual(['--userns=host']);
+
+    process.env.SPOON_AGENT_BOX_USERNS = '';
+    ({ boxUsernsArgs } = await loadVolumeSpec());
+    expect(boxUsernsArgs()).toEqual([]);
+    delete process.env.SPOON_AGENT_BOX_USERNS;
+  });
+
+  test('execArgv places -u after the workdir and before the container name', async () => {
+    const { execArgv } = await loadVolumeSpec();
+    expect(
+      execArgv({
+        containerName: 'spoon-box-gabriel',
+        command: ['ls', '-la'],
+        environment: { HOME: '/home/gabriel' },
+        containerCwd: '/home/gabriel',
+        user: 'gabriel',
+      }),
+    ).toEqual([
+      'exec',
+      '-e',
+      'HOME=/home/gabriel',
+      '-w',
+      '/home/gabriel',
+      '-u',
+      'gabriel',
+      'spoon-box-gabriel',
+      'ls',
+      '-la',
+    ]);
+  });
+
+  test('execArgv omits -u when no user is given', async () => {
+    const { execArgv } = await loadVolumeSpec();
+    const argv = execArgv({
+      containerName: 'c',
+      command: ['true'],
+      environment: {},
+      containerCwd: '/',
+    });
+    expect(argv).not.toContain('-u');
+  });
+
   test('treats a spawn failure (no exitCode) as a non-zero exit, not empty success', async () => {
     const { normalizeRunResult } = await loadVolumeSpec();
     // This is what execa returns with `reject: false` when the runtime binary is