home-network-k3s-impl/runbooks/image-automation.md

image-automation — Flux's image-update-automation cannot write back to git

Alert: ImageUpdateAutomationFailing (warning, 30m) File: platform/monitoring/alerts.yaml, group platform-health.automated-updates Expression: max by (namespace, name) (gotk_reconcile_condition{kind="ImageUpdateAutomation", type="Ready", status="False"}) == 1

What this means here

ImageUpdateAutomation is the write-back half of hands-off updates (ADR-0009): it commits new image tags into git so Flux then deploys them. When it is Ready=False, stable image advances silently stop — nothing breaks, nothing degrades, the platform just quietly stops receiving updates. That is the R-UPD-02 failure mode this alert exists for.

Read this first: on this cluster, image automation is authored and DELIBERATELY DISABLED. It has been that way since 2026-08-24, pending (a) a Gitea write credential for the automation to push with and (b) flux install --components-extra=image-reflector-controller,image-automation-controller. The line is still commented out in platform/kustomization.yaml. So:

• If this alert fires, the most likely explanation is that the feature was partially enabled — someone uncommented the component or a rendered app started emitting ImageRepository/ImagePolicy CRs whose controllers are not installed.
• Rendered apps emit those CRs by default; catalog/render.py --no-image-automation is the documented workaround for exactly this.
• There is consequently no real incident history for this alert. Everything below is mechanism, not post-mortem, and it says so honestly rather than inventing precedent. This alert is currently INERT. count(gotk_reconcile_condition) returned 0 series on prod on 2026-09-13 — there is no Flux-controller scrape job among Prometheus's 19 jobs, so every gotk_* rule evaluates against nothing. Read the CRs directly with the commands below, and see /runbooks/targets-down for the full list of inert rule groups.

Running the commands in this runbook

kubectl does not work on the operator workstation. The toolchain lives only in the pinned dev container, and the host's k3s-oidc context hangs on a browser prompt once its token expires — that hang is not the cluster being down. Every command below runs as:

infra/devcontainer/dev.sh run bash -c 'kubectl --context k3s-prod get nodes'

Always pass --context k3s-prod explicitly. dev.sh merges BOTH clusters into one kubeconfig and picks a current-context per invocation, and that default has already changed once — it was k3s-dev until dev was decommissioned on 2026-09-13, and is k3s-prod now. A command that names its context means the same thing next month as it does today; one that relies on the default does not, and the failure is silent (it answers confidently about the other cluster). CLUSTER=prod infra/devcontainer/dev.sh run kubectl ... selects it explicitly, and every invocation prints a banner naming the cluster it is about to talk to — read it. Do not run two dev.sh invocations at once; they share one container and interfere.

USE FULLY-QUALIFIED RESOURCE NAMES, ALWAYS. Three CRDs on this cluster register the kind Backup: longhorn.io/v1beta2, postgresql.cnpg.io/v1 and velero.io/v1. The bare short name resolves to Longhorn's, which holds zero objects — so kubectl get backup -A prints "No resources found" on a cluster holding 6 Velero backups and 27 CNPG backups. Verified on prod 2026-09-13. Reading that as "the backups are gone" and acting on it turns a false negative into real data loss. Write backups.velero.io, backups.postgresql.cnpg.io, clusters.postgresql.cnpg.io, settings.longhorn.io, volumes.longhorn.io, nodes.longhorn.io.

Mutating kubectl (apply, patch, annotate, rollout) and flux reconcile are blocked for agents here: every durable change goes through git. main is a protected branch — a direct push is rejected. A change lands by pushing a branch, opening a PR, and merging it once the gate is green; that merge is the deploy. Where this runbook gives a mutating command it is for an operator, and it says so.

First commands

Are the controllers even installed?

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod -n flux-system get deploy | sort; echo; \
   kubectl --context k3s-prod api-resources --api-group=image.toolkit.fluxcd.io'

The automation objects and their messages:

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod get imageupdateautomations.image.toolkit.fluxcd.io -A \
     -o custom-columns=NS:.metadata.namespace,NAME:.metadata.name,READY:.status.conditions[?\(@.type==\"Ready\"\)].status,MSG:.status.conditions[?\(@.type==\"Ready\"\)].message,LASTRUN:.status.lastAutomationRunTime'

The controller log — the git error is always in here:

infra/devcontainer/dev.sh run bash -c \
  'kubectl --context k3s-prod -n flux-system logs deploy/image-automation-controller --tail=100 2>&1 | tail -40'

Is the repo configured with a write path at all?

grep -rn "image-automation\|ImageUpdateAutomation\|components-extra" platform/kustomization.yaml bootstrap/ clusters/ 2>/dev/null | head -20

Likely causes, most likely first

1. The controllers are not installed (expected state here)

api-resources --api-group=image.toolkit.fluxcd.io returns nothing, or the deployments are absent. Then the CRs are inert objects and the alert reflects a half-enabled feature. Remediation: either finish enabling it (an operator runs flux install --components-extra=... — note that Flux's own controllers were installed imperatively and carry no Flux ownership labels, so nothing under clusters/** can install a controller or change a controller flag), or stop rendering the CRs with catalog/render.py --no-image-automation.

2. No git write credential

The automation must push. Prod's source is http://gitea.gitea.svc.cluster.local:3000, and the read-only source credential is not a write credential. The controller log will say authentication failed or permission denied. Remediation: a Gitea token in a SOPS-encrypted Secret referenced by the GitRepository/automation, added in git — and note the standing rule from the OIDC incident: non-secret environment-specific values must not live inside an encrypted Secret, because ${BASE_DOMAIN} substitution can never reach inside one.

3. It cannot push because the branch moved

Automation commits to a branch; a force-push or a protected branch rejects it. The log names the ref.

4. The commit is being made but the Kustomization is not picking it up

Then this is not the right runbook — go to /runbooks/flux-reconcile.

When to escalate or stop

• This is a warning with a 30m for for a reason: nothing is broken. Do not treat it as an outage. The consequence is "no new image versions", which is measured in days.
• Do not create a Gitea write credential ad hoc. It is a new secret in the DR path and belongs to the operator, SOPS-encrypted, in git.
• Do not enable the extra Flux controllers to make the alert stop. Enabling automation on a cluster that has never run it will start proposing image bumps across every workload at once; that is a planned change, with /runbooks/update-rollback as its companion.
• If the alert is firing because the feature is half-enabled, the honest fix is to finish or to revert — both are git changes and both want the operator's decision.

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Source of truth: runbooks/image-automation.md. Index: /runbooks/ Records: DECISIONS-LOG.md (image automation authored-and-disabled since 2026-08-24; the Flux controllers are outside Flux's own inventory).