etherpad-lite/doc/admin/updates.md

Etherpad updates

Etherpad ships with a built-in update subsystem.

• Tier 1 (notify) — default. A banner appears in the admin UI when a new release is available, and pad users see a discreet badge if the running version is severely outdated or flagged as vulnerable. No execution.
• Tier 2 (manual click) — admins on a git install can click "Apply update" at /admin/update. Etherpad drains active sessions, runs git fetch / checkout / pnpm install / pnpm run build:ui, and exits with code 75 so a process supervisor restarts it on the new version. Auto-rolls back on failure.
• Tier 3 (auto with grace window) — designed, not yet implemented.
• Tier 4 (autonomous in maintenance window) — designed, not yet implemented.

Settings

In settings.json:

{
  "updates": {
    "tier": "notify",
    "source": "github",
    "channel": "stable",
    "installMethod": "auto",
    "checkIntervalHours": 6,
    "githubRepo": "ether/etherpad",
    "requireAdminForStatus": false,
    // Tier 2+ knobs (only meaningful at tier "manual" or higher):
    "preApplyGraceMinutes": 0,
    "drainSeconds": 60,
    "rollbackHealthCheckSeconds": 60,
    "diskSpaceMinMB": 500,
    "requireSignature": false,
    "trustedKeysPath": null
  },
  "adminEmail": null
}

Setting	Default	Notes
updates.tier	"notify"	One of "off", "notify", "manual", "auto", "autonomous". Higher tiers are silently downgraded if the install method does not allow them. PR 1 only honors "notify" and "off".
updates.source	"github"	Reserved for future alternative sources. Only "github" is implemented.
updates.channel	"stable"	Reserved. Stable releases only.
updates.installMethod	"auto"	One of "auto", "git", "docker", "npm", "managed". Auto-detects via filesystem heuristics. Set explicitly to override.
updates.checkIntervalHours	6	How often to poll GitHub Releases.
updates.githubRepo	"ether/etherpad"	Override for forks.
updates.requireAdminForStatus	false	Lock the /admin/update/status endpoint to authenticated admin sessions. Default false matches existing Etherpad behavior — /health already exposes releaseId publicly, and changelog data comes from a public GitHub release. Set true to hide the full update payload from non-admins without disabling the updater (tier: "off" is the heavier opt-out that removes the endpoints entirely).
updates.preApplyGraceMinutes	0	Tier 3 only. Wait this many minutes between detecting a new release and starting the drain so the admin can cancel. Has no effect at tier "manual".
updates.drainSeconds	60	How long to broadcast "restart imminent" announcements to active pads before exiting. T-60 / T-30 / T-10 broadcasts fire automatically at the matching offsets within this window.
updates.rollbackHealthCheckSeconds	60	After a fresh boot post-update, give /health this long to come up. If it doesn't, RollbackHandler restores the previous SHA.
updates.diskSpaceMinMB	500	Pre-flight refuses to start an update unless the install volume has at least this many MB free.
updates.requireSignature	false	When true, refuse updates whose tag is not signed by a trusted key. Verification is done via git verify-tag <tag> against the user's GPG keyring. Default false because Etherpad's release process does not yet sign tags consistently — turning the check on by default would block every Tier 2 update. Set true if you run your own builds or have imported a fork's keys.
updates.trustedKeysPath	null	Override the keyring location passed to git verify-tag via the $GNUPGHOME env var. Useful when the trusted keys live in a dedicated keyring outside the Etherpad user's home. Only meaningful when requireSignature: true.
adminEmail	null	Top-level. Contact for admin notifications. Setting it enables the email nudges below.

What "outdated" means

• severe — running at least one major version behind the latest release.
• vulnerable — the running version is below a vulnerable-below threshold announced in a recent release. Releases declare these via a <!-- updater: vulnerable-below X.Y.Z --> HTML comment in their body. The newest such directive wins.

Email cadence (when adminEmail is set)

Trigger	First send	Repeat
Vulnerable status detected	Immediate	Weekly while still vulnerable
New release announced while still vulnerable	Immediate	n/a (one event per tag change)
Severely outdated detected	Immediate	Monthly while still severely outdated
Up to date	No email	—

If adminEmail is unset, the updater never sends mail. The admin UI banner and the pad-side badge still work without it.

PR 1 ships the cadence machinery but does not yet wire a real SMTP transport — emails are logged with (would send email) until a future PR adds the transport. The dedupe state still advances correctly so admins are not bombarded once SMTP is wired.

Pad-side badge

Pad users see no version information by default. A small badge appears in the bottom-right corner only when:

• The instance is severe (one or more major versions behind), or
• The instance is vulnerable (running below an announced threshold).

The public endpoint /api/version-status returns only {outdated: null|"severe"|"vulnerable"} — it never leaks the running version, so attackers do not gain a fingerprint vector.

Disabling everything

Set updates.tier to "off". No HTTP request will leave the instance and no banner or badge will render.

Privacy

The version check sends no telemetry. Etherpad fetches the public GitHub Releases API (api.github.com/repos/<repo>/releases/latest) with If-None-Match to be cache-friendly. The only metadata GitHub sees is the same as any other GitHub API client — your IP and a User-Agent: etherpad-self-update header. No instance ID, no version, no identifiers travel upstream.

How install method is detected

updates.installMethod defaults to "auto", which uses these heuristics in order:

1. /.dockerenv exists → "docker".
2. .git/ directory present and the install root is writable → "git".
3. package-lock.json present and writable → "npm".
4. Otherwise → "managed".

Set the value explicitly if the heuristics get it wrong (e.g., a docker container that bind-mounts a writable git checkout).

In PR 1 (notify only) the install method does not change behavior — every install method gets the banner. From PR 2 onward the install method gates whether the manual-click and automatic tiers can run; only "git" is initially supported for write tiers.

Tier 2 — manual click

Tier 2 is opt-in. To enable: set updates.tier: "manual" and ensure your install was deployed via git (not docker / npm / managed package).

Process supervisor is required

Etherpad applies an update by exiting with code 75 so a process supervisor restarts it. Without a supervisor the instance simply exits and stays down. Common supervisor setups:

• systemd: add Restart=on-failure + RestartSec=5 to your unit file.
• pm2: the default behaviour restarts on exit.
• docker: add --restart=unless-stopped (Tier 2 itself is not supported on docker installs anyway, but if you wrap your own image around a git checkout this applies).

What clicking "Apply update" does

1. Lock acquire — var/update.lock (PID-based, stale locks reaped automatically).
2. Pre-flight checks — install method writable, working tree clean, free disk ≥ diskSpaceMinMB, pnpm on PATH, target tag exists at the configured remote, signature verifies (if requireSignature: true). On failure, state goes to preflight-failed with a typed reason; the admin sees a banner and clicks Acknowledge to clear it. No filesystem mutation has happened — nothing to roll back.
3. Drain — drainSeconds window during which T-60 / T-30 / T-10 announcements broadcast to every connected pad and new socket connections are refused. Click Cancel during this window to abort cleanly.
4. Execute — git fetch --tags origin, git checkout <tag>, pnpm install --frozen-lockfile, pnpm run build:ui. Output streams to var/log/update.log (rotated 10 MB × 5).
5. Exit 75 — the supervisor restarts on the new version.
6. Health check — RollbackHandler arms a rollbackHealthCheckSeconds timer at boot. When /health responds 200 (i.e., Etherpad reaches the RUNNING state) the timer cancels and the state lands on verified.

Failure modes

What went wrong	Resulting state	Admin action
Pre-flight check fails	preflight-failed	Click Acknowledge after fixing the underlying issue (free up disk, clean working tree, etc.).
git fetch / git checkout fails mid-flow	rolled-back	Informational. The working tree is back where it started; click Acknowledge to clear.
pnpm install or pnpm run build:ui fails	rolled-back	Same as above. The lockfile and SHA are restored.
/health doesn't come up within rollbackHealthCheckSeconds	rolled-back	Same — RollbackHandler restores the previous SHA + lockfile and exits 75 again.
The new version crashes at boot more than twice (bootCount > 2)	rolled-back	Crash-loop guard kicks in regardless of the health-check timer.
Rollback itself fails (e.g., pnpm install errors restoring old lockfile)	rollback-failed	Manual intervention required. The admin banner switches to a strong red alert. Restore the install by hand, then click Acknowledge to clear the lock and re-allow Tier 2 attempts.

Endpoints

All Tier 2 endpoints require an authenticated admin session (is_admin: true) regardless of requireAdminForStatus.

• POST /admin/update/apply — start an apply. Returns 202 {accepted, drainEndsAt} once the drain begins. Body unused.
• POST /admin/update/cancel — cancel during pre-flight or drain. Returns 409 once the executor has begun mutating the filesystem (state machine guarantees we either complete or roll back from there).
• POST /admin/update/acknowledge — clear a terminal preflight-failed / rolled-back / rollback-failed state back to idle.
• GET /admin/update/log — tail the last 200 lines of var/log/update.log. Plain text. Used by the in-progress UI.

Signature verification

Default off. Etherpad releases are not yet consistently signed; turning verification on by default would block every Tier 2 update. To enable:

"updates": {
  "requireSignature": true,
  "trustedKeysPath": "/srv/etherpad/keys"   // optional — defaults to the OS user keyring
}

The check shells out to git verify-tag <tag>. The keyring at trustedKeysPath is passed to git via GNUPGHOME. If trustedKeysPath is null (default), the OS user's default keyring is used.

Docker-friendly update flows (future work)

Tier 2 deliberately refuses to apply on installMethod: "docker" because in-container git fetch / pnpm install / build:ui doesn't survive a container restart — the orchestrator brings the container back up on the same image tag and the work is lost. Docker installs stay on Tier 1 (banner + version status) for now.

The right way to give docker admins an in-product Apply button is to delegate to the orchestrator rather than mutate the container. Two patterns to consider in a follow-up PR:

• Instructions-only. When the page detects installMethod: docker and a newer release exists, swap the policy-denial copy for actionable instructions (docker pull etherpad/etherpad:<tag> for plain docker; docker compose pull && docker compose up -d for compose). Cheap, no new attack surface.
• Deploy webhook. New setting updates.dockerWebhook. When set, the Apply button on a docker install POSTs to the configured URL and trusts the orchestrator (Render / Railway / Fly / Portainer / Coolify / GitHub Actions — they all expose redeploy webhooks) to do the actual pull-and-recreate.

Direct Docker-socket access (mount /var/run/docker.sock into the container) is out of scope — anyone who escapes the Etherpad process via that socket gets root on the host. Admins who want fully autonomous docker updates should run Watchtower alongside Etherpad rather than bake equivalent privilege into Etherpad itself.