Docker / Images, Dockerfiles & Build Reliability
Compare a Docker image's content identity with its mutable tags
A tag can move while an existing container continues using older content. Inspect local image identity and registry digests.
Environment and inputs: Docker Engine · Compose v2 and Buildx where specified; Linux containers unless noted. Verify daemon context, installed feature support and authorized host or Swarm manager access first.
Start with this check
Confirm the environment and replace sample objects, namespaces, images, paths and hosts with approved targets. Share only relevant, sanitized output. Follow the workload owner’s process for changes.
docker image inspect --format '{{.Id}} {{json .RepoTags}} {{json .RepoDigests}}' app:releaseRead the result
The image ID and recorded repo digests describe local content and known registry associations. A missing repo digest can be normal for a locally built image.
Resolve and verify
Compare the container's image ID with the verified release artifact and deployment reference. Use an approved immutable digest where the release process supports it.
Before changing production
Do not assume the same tag on two hosts proves identical content or retag an image to hide a mismatch.