Image Cleanup — ACR & local Docker

Images pile up on ACR (meshweaver.azurecr.io), not on your machine. Two sources feed it: every green merge to main publishes a 3.0.0-ci.<n> version tag (plus a git-sha and per-RID tags) via main-cd.yml, and any manual dotnet publish -t:PublishContainer pushes whatever tag you named. That publish talks to the registry directly — it does not create a local Docker image. This page is how to clear the accumulation out safely.

🚨 The golden rule: never delete an image that any deployment references. A tag that looks "old" by name or date may still be live in another namespace. Always build the keeper list from what is actually deployed across every namespace — never from the tag name or push date.

The repos under meshweaver.azurecr.io:

Repo What it holds Cleanup posture
memex-portal-ai The portal image — one tag per deploy Where the bloat is; prune aggressively
memex-migration The DB-migration image A few tags; keep the live one + latest
memex-portal-next The portal-next client image Keep the tags matching live/kept portal versions
mw-plugin-test Plugin-CI test image (also published to GHCR) Keep the newest; not deployment-critical
memex-portal-ai-base The custom runtime base image every portal build layers on Never delete latest — it breaks every future build

🚨 memex-portal-ai, memex-migration, mw-plugin-test and memex-portal-next form the four-image set that .github/scripts/check-image-set.sh asserts is complete for a given commit, and CD's reconciler republishes when it is not. Deleting one leg's tag for a commit makes that commit look unpublished to the reconciler. Prune whole versions, never one repo's tag in isolation.

Step 1 — Build the keeper list (do this FIRST)

List every image referenced by a live Deployment in all namespaces on the shared cluster. The Fleet Console (/Hosting/Console) shows the RUNNING version per recorded instance; the cluster read below is break-glass — it covers namespaces no record describes, which is exactly why a cleanup must not trust the record list alone (OperatingFromThePortal). The cluster is private — kubectl only via az aks command invoke.

Query every namespace, never a hand-written list — the cluster runs at least three portal namespaces (portalNamespaces in deploy/aks/infra/main.bicep lists them), and a loop that names only some of them silently omits a live image from the keeper list, which is exactly how you delete something in use:

az aks command invoke -g <aks-resource-group> -n <aks-cluster> --command "\
  kubectl get deploy,statefulset,job,cronjob -A \
    -o jsonpath='{range .items[*]}{.metadata.namespace}{\"\t\"}{.spec.template.spec.containers[*].image}{\"\n\"}{end}' \
  | sort -u"

-A covers namespaces added since this page was written. Include Jobs and StatefulSets too — the migration ships as a Job, so a get deploy-only sweep misses the memex-migration tag entirely.

Everything that prints is a hard keeper. Example output shape:

Add to the keeper list:

Everything in ACR that is not on this list is safe to delete.

Step 2 — List the ACR tags (newest first)

az acr repository show-tags -n meshweaver --repository memex-portal-ai \
  --orderby time_desc --detail --query "[].{tag:name,updated:lastUpdateTime}" -o tsv

az output can carry non-ASCII bytes that crash the Windows console (cp1252). Pipe through tr -cd '\11\12\15\40-\176' to strip them. The same applies to az aks command invoke output.

Step 3 — Delete the old tags

Deleting a tag removes its manifest; ACR ref-counts layers, so layers shared with a kept image survive — you only reclaim what nothing else points at. Deletion is irreversible (no recycle bin), which is why Step 1 comes first.

Delete one tag:

az acr repository delete -n meshweaver --image memex-portal-ai:deploy-9a3488ed4 --yes

Delete many — keep the list explicit so a keeper can never be swept in by a pattern:

KEEP="nicepicker-09149ea0d settingsfix-bfdd797ae cmdux-fdaa94971 fixall-f560d20d6"
for tag in $(az acr repository show-tags -n meshweaver --repository memex-portal-ai -o tsv | tr -cd '\11\12\15\40-\176\n'); do
  case " $KEEP " in
    *" $tag "*) echo "keep   $tag" ;;
    *)          echo "delete $tag"; az acr repository delete -n meshweaver --image "memex-portal-ai:$tag" --yes >/dev/null ;;
  esac
done

Repeat for memex-migration with KEEP="settingsfix-bfdd797ae latest". Skip memex-portal-ai-base entirely — its only tag, latest, is a keeper.

Optional — automate ongoing hygiene

On a Premium ACR you can stop the pile-up at the source instead of hand-pruning:

Automation is good for the untagged/old long tail; the live keeper rule still stands — a retention window must be long enough that no currently-deployed tag ages out, or pin keepers with an exclusion.

🚨 "Is the purge running?" — and the two things that answer it wrongly

az acr task list --registry meshweaver -o table         # ← the TASK's status is the answer

A DISABLED TASK STILL REPORTS AN ENABLED TIMER TRIGGER. Measured 2026-09-12: both tasks read status: Disabled while trigger.timerTriggers[0].status still read Enabled at 0 3 * * *. Read the task's status; the trigger's is about the trigger, and a reader who checks the schedule concludes a paused purge is live.

And .github/acr-retention/ is a RECORD, not the registry. Nothing deploys from it, so a file saying Enabled is evidence of what someone last wrote down. acr-retention-tasks.sh verify is what relates the two.

State as this is written: purge-old-images is PAUSED while artifact protection is completed (Memex#219). The condition for re-enabling is recorded in .github/acr-retention/tasks.json under pause.reEnableWhen — re-enabling before it restores the exposure the pause is holding off.

🚨 --keep N is not "keep the N newest tags"

It is applied after --ago, over the already-eligible set: of the tags older than the window, spare the N newest. A tag younger than --ago is never eligible however many newer builds exist — and one older than it is spared only until N more tags cross the same line behind it.

So --keep is not keeper protection, and on a busy repository it is worth almost nothing. Measured on memex-portal-ai: 193.1 tags/day, so a --keep 10 window is consumed in ~1.2 hours, and the oldest tag in the repository was exactly 7 days old — --ago 7d was the entire policy. The durable protection is a lock, and it has to cover the tag, the manifest and the platform manifests under a multi-arch index: ArtifactRetentionInterlock.

Local Docker cleanup

Because the portal/migration images live on ACR (never pulled locally), your local Docker holds only reusable infrastructure images — the Aspire/testcontainers dependencies (pgvector/pgvector, dpage/pgadmin4, mcr.microsoft.com/azure-storage/azurite, testcontainers/ryuk). Deleting those just forces a re-pull (~2 GB) next aspire run/test run, so leave them unless you are truly out of disk.

What is always safe to reclaim:

docker container prune -f     # stopped containers (left over from old aspire runs / testcontainers)
docker builder prune -f       # build cache
docker image prune -f         # DANGLING (untagged) images only — never touches tagged infra images

Check what is reclaimable first, and how much:

docker system df              # TYPE / SIZE / RECLAIMABLE per category

For a full sweep (stopped containers + unused networks + dangling images + build cache) in one go:

docker system prune -f        # safe: does NOT remove tagged images that are in use

⚠️ Do not run docker system prune -a (or docker image prune -a) unless you intend to drop the reusable infra images too — -a removes every image not attached to a running container, forcing the multi-GB re-pull. The non--a forms above are the routine cleanup.

See also