Drift¶

Drift tells you that a project has work that is not released or not promoted. Imbi uses the word for three different things. Each one has its own badge and its own data.

The Drifted count on the projects list counts only the first two kinds. It never reads release drift.

Drift verdicts from CI¶

Imbi does not calculate drift from your files. Your CI pipeline decides, for each commit, if the commit changes something that needs a release. CI writes the answer as a git note on the commit, in the refs/notes/imbi-drift namespace:

{"drift_detected": false}

A note can also have drift_paths, a list of the paths that caused a true verdict. Imbi ignores a note that is not valid JSON or that has no boolean drift_detected. Imbi stores each verdict in the ClickHouse commit_drift table, one row for each commit.

Each commit has one of three states:

The rule: only proven clean is clean¶

Imbi shows drift unless CI answered false for every commit in the range. One true verdict shows drift. One commit with no verdict also shows drift. Imbi does this so that a missing note can never hide work.

Thus a project whose CI writes no drift notes shows drift for every difference. To hide drift for commits that do not matter (for example, documentation or CI configuration), make your CI write a false note for those commits.

When Imbi cannot read the verdict store, it also shows drift.

How verdicts get into Imbi¶

If a webhook delivery was lost, a commit stays with no verdict and shows drift. To repair it, open the Doctor tab (the stethoscope icon) and click Sync Commits & Tags. The button shows when you have project:commits:write. The sync icon on the Releases and Deployments tabs runs the same commit sync.

A removed note does not remove the verdict. Imbi keeps the last verdict that it recorded.

Environment drift¶

Environments are in one list, ordered by their sort order. An environment with the terminal flag ends a pipeline. The next environment starts a new pipeline. Imbi compares each pair of adjacent environments in one pipeline. It never compares across the end of a pipeline.

For each pair, Imbi compares the commit that each environment runs:

1. If the two commits are the same, there is no drift. A different tag on the same commit is not drift.
2. If the commits are different, Imbi finds the commits between them. The pair shows drift unless every one of those commits has the verdict false.
3. If Imbi cannot find both commits, or cannot put them in order, the pair shows drift.

The earlier environment in the pipeline runs the newer code. For example, with Testing, Staging, and Production, the pair "Testing → Staging" shows drift when Testing runs commits that are not in Staging yet.

The badge¶

The projects list shows one badge for each pair with drift, for example Δ T → S. The letters are the initials of the environment names. The badge has the color of the target environment, or amber when the target has no color.

Click the badge to open the Deployments tab of the project, with the target environment selected. From there you can promote. See Releases and deployments.

The badge shows only for a project with a deployable project type.

Commit-to-release drift (C → R)¶

This kind applies to a project with a releasable project type. The range is the commits after the commit of the latest release tag. Imbi finds the latest tag with the same rule as the Releases tab.

The badge Δ C → R (amber) shows when:

• there is at least one commit after the latest tag, and
• the range is not proven clean (see the rule).

Click the badge to open the Releases or Deployments tab of the project, where you can cut a release.

A project with no release tag has no C → R range and shows no C → R badge.

Release drift¶

A release has its own drift value. It is the CI verdict for the one commit that the release tag points at. It is not a value for the range of commits in the release.

When the value changes to true, Imbi adds a blocker of type drift to the release, with the description "CI reported configuration drift on commit \<sha>". When a later verdict is not true, Imbi resolves that blocker with the note "drift note cleared". A blocked release cannot be promoted. See Blockers.

In the release history, a release with the value true shows the amber badge Drift. Hover over it to see "CI reported configuration drift on this release's commit".

Drift on the projects list¶

The URL keeps the filters (has_drift=1 and drifts=), so you can share a filtered list.

Drift on the project page¶

Ready to ship¶

The Deployments tab (or the Releases tab) shows a rocket icon, Ready to ship, when:

• Deployments: two adjacent environments run different commits, and the range between them is not proven clean.
• Releases: the project has commits after its latest tag, and they are not proven clean.

A range is proven clean only when every commit in it has a false verdict. This is the rule of the projects-list badges, so the icon and the badges agree.

Commit markers¶

Commit lists on the Deployments and Releases tabs show one marker for each commit:

The card on the Releases tab counts all commits after the tag. When every one of them has a false verdict, it shows "N commits since the last release, none flagged as drift" instead of "N commits ready to release". You can still cut a release from it.

Troubleshooting¶