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 group access token on the group that owns the project (Settings → Access tokens), or a group service account and a personal access token for it. Either one is a bot identity that outlives the person who created it, which is what you want for a credential the instance uses unattended.

Scope	api
Role	Developer to push deploy branches; Maintainer to also manage the webhook and open merge requests
Expiry	Required for a group access token; a group service account PAT can be non-expiring on self-managed (see below)

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 rotatable so Windmill can renew it before it expires. 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.

A group access token is renewed through GitLab's own self-rotation endpoint. GitLab issues one to a per-group bot user and keeps it as that user's personal access token, so the token rotates itself with no credential over the group involved, and Windmill never holds one.

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 stores the whole remote URL, credential included, in a secret variable and points the resource at it ("url": "$var:u/you/gitlab_group_project_url").

Renewal rewrites whichever of the two holds the URL, so a URL pasted straight into the resource is renewed as well. The variable is still the better place for it: the credential stays out of the resource, and everything else that references the variable keeps working when the token changes. What cannot be renewed is a variable held in an external secret backend, which Windmill can read but does not own the write to; that is reported on the repository.

Expiry and renewal

Windmill reads expires_at from the token itself 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, writes the replacement back to the variable, and verifies it. Only the token can rotate itself, so a token without api (or self_rotate) is a permanent warning rather than something Windmill can fix.

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.

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.