windmill/docs/git-sync-gitlab-setup.md

Git sync with GitLab

GitLab has no equivalent of a GitHub App, so there is nothing to install and no consent screen. What Windmill needs instead is one credential you create in GitLab and paste once. With it, a GitLab repository gets the same managed features an app-backed GitHub repository has: instant pull over a webhook, merge requests opened on deploy, and a diff preview posted onto the merge request.

The credential

Create a project access token on the project you are syncing (Settings → Access tokens). It is a bot identity that outlives the person who created it, which is what you want for a credential the instance uses unattended, and it reaches exactly the one project.

Scope	api
Role	Developer to push deploy branches; Maintainer to also manage the webhook and open merge requests
Expiry	Required. A group service account PAT can be non-expiring on self-managed (see below); an access token cannot

Use a separate token per repository. A group access token works too and reaches every project in the group, which is convenient for a lot of repositories — but Windmill stores the credential per repository, and renewal rewrites the repository it renewed for. Any other repository holding that same token keeps the revoked one and stops syncing until you paste a new token there. Each stranded repository says so on its card, so it is visible rather than silent, but a token per repository avoids it entirely.

api is a superset: it authorizes Git over HTTPS as well, so no separate write_repository is needed to clone and push, and it is also what makes the token renewable. A write_repository-only token can still push, but Windmill cannot inspect or renew it and reports that in the workspace's git sync settings.

The identity Windmill acts as

GitLab issues an access token to a bot user it creates for it — project_<id>_bot_… for a project token, group_<id>_bot_… for a group one — and the bot's display name is the name you gave the token. That name is the byline on everything Windmill does: the author of deploy commits, of the merge requests it opens, and of the preview notes it writes. Name it for what it is, windmill-sync or similar, rather than something only you will recognise.

Each token you create adds another bot member to the project or group. Renewal does not — it keeps the same bot — so a repository accumulates one bot, not one per year.

Renewal goes through GitLab's own self-rotation endpoint. Both kinds of access token are held as their bot user's personal access token, so the token rotates itself and Windmill never needs a credential with rights over the project or group.

Connecting a repository

In the resource form for a git_repository resource, use the GitLab button: paste the instance URL and the token, pick a project from the list, and Windmill keeps the token for you. The resource itself gets the plain remote URL ("url": "https://gitlab.com/group/project.git"), with no credential in it.

The token is stored encrypted on the workspace, keyed by the repository it was issued for rather than by the resource naming it, the same way a GitHub App installation is held against the account it covers. Nothing reads it back out over the API: the server attaches it when it talks to GitLab, and a sync job receives it only against its own job token. Repointing a resource's url asks for a different repository's token and finds none, so the edit carries nothing with it; a repository that genuinely moved needs its token entered again.

Because the repository is the key, the token is stored the moment you pick the project, before the resource is saved. Renaming the resource later keeps it, and cancelling the edit leaves a stored token that nothing uses until some resource points at that repository again.

Forks of the workspace read this one copy rather than getting their own, so renewal reaches all of them at once and the token is not duplicated into every descendant workspace.

Treat workspace admin as equivalent to holding the token. An admin of the workspace, or of any fork below it, can point a repository at a sync script they wrote and have that job request the credential, exactly as they can for a GitHub App installation token. Storing it this way keeps it out of the variables API and out of every fork's own storage; it is not a boundary against the admins of those workspaces.

A URL with the token written into it, in the resource or in a secret variable the resource points at ("url": "$var:..."), is a plain git remote: it syncs on deploy and by polling, and nothing else. Windmill does not know the token is there, so it registers no webhook, opens no merge request, and neither reports nor renews its expiry. Use the GitLab button to hand the token to Windmill if you want any of that.

Expiry and renewal

Windmill reads expires_at from the token it holds and shows it on the repository in the workspace's git sync settings. Within three weeks of expiry it rotates the token through GitLab's own POST /personal_access_tokens/self/rotate, stores the replacement, and verifies it. Only the token can rotate itself, so one without api (or self_rotate) is a permanent warning rather than something Windmill can fix.

Only the workspace that holds a credential renews it, so one renewal serves the whole fork chain instead of each fork racing to renew the same token. A fork reads the parent's without holding one, so it never renews; the parent does, and every fork sees the replacement at once.

Rotation is deliberately never retried. GitLab revokes the old token the instant it issues the replacement, and presenting an already-rotated token to /rotate again is treated as reuse: it revokes the whole token family, including the live replacement. So a rotation that succeeded at GitLab but failed to persist is surfaced as an error to act on, not retried.

Non-expiring tokens are possible only for a group service account PAT on self-managed, with require_personal_access_token_expiry turned off in the instance's application settings. A group access token is always rejected without an expires_at.

What each managed feature needs

Feature	Needs
Instant pull	A project hook Windmill creates, so Maintainer; and a Windmill base URL GitLab can reach
Merge requests on deploy	Developer, plus the api scope
Diff preview on a merge request	The project hook, plus permission to post merge request notes

Instant pull falls back to checking the tracked branch about every minute when the hook cannot be created or delivered, so nothing silently stops syncing.

Self-managed differences

Webhooks to a private network are blocked by default. GitLab refuses to create a hook pointing at a private or local address until an administrator enables Allow requests to the local network from webhooks and integrations (Admin → Settings → Network → Outbound requests, allow_local_requests_from_web_hooks_and_services). A Windmill instance on the same private network as GitLab needs this; without it, hook creation fails with a "blocked" error and the repository keeps polling.

A relative-URL install is not supported. GitLab can be served under a path prefix (https://example.com/gitlab), and that prefix cannot be told apart from a group of the same name: example.com/a/b/c.git is either group a/b project c, or prefix a with group b project c. Windmill reads it as the nested group, so on a relative-URL install it derives the wrong API base and the managed features stay unavailable. Such a repository still syncs through its token URL, which needs no API base.

Everything else is identical: Windmill talks to <your-gitlab>/api/v4 and needs no inbound access of its own beyond the hook deliveries.

The deploy preview is a note, not a pipeline status

On GitHub the preview is a check run: its own object, advisory unless the repository makes it required. GitLab has no equivalent. Its only comparable primitive is a commit status, and posting one has side effects Windmill will not impose on a project:

• GitLab files the status as a job inside whatever pipeline already covers that commit, so a failed Windmill status fails the project's own pipeline, and its reviewers see their test suite as failed.
• allow_failure is ignored on the commit-status endpoint, so the status cannot be made advisory.
• On a commit with no pipeline it creates an external pipeline instead, which then gates merging under Pipelines must succeed, including while it is still running.

So on GitLab the preview lives entirely in a merge request note that Windmill keeps up to date: it carries the workspace, the status line, the commit, a link to the job, and the full list of changes merging would deploy. A note cannot block a merge or change what the project's own CI reports.

The note is upserted rather than appended, so a merge request accumulates one Windmill comment however many times it is pushed to.