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DCA · Question #48
DCA Question #48: Real Exam Question with Answer & Explanation
The correct answer is C: Use the DTR web UI to make the tag immutable.. Docker Trusted Registry (DTR) provides a specific feature to make image tags immutable, preventing them from being overwritten once pushed to a repository.
Submitted by andres_qro· Apr 18, 2026Image Creation, Management, and Registry
Question
In Docker Trusted Registry, how would a user prevent an image, for example 'nginx:latest' from being overwritten by another user with push access to the repository?
Options
- ATag the image with 'nginx:immutable'
- BRemove push access from all other users.
- CUse the DTR web UI to make the tag immutable.
- DKeep a backup copy of the image on another repository.
Explanation
Docker Trusted Registry (DTR) provides a specific feature to make image tags immutable, preventing them from being overwritten once pushed to a repository.
Common mistakes.
- A. Simply tagging an image with a descriptive name like 'nginx:immutable' does not automatically confer immutability properties; it requires a registry-level configuration.
- B. Removing push access from all other users is too restrictive as it would prevent them from pushing any new tags or images to the repository.
- D. Keeping a backup copy of the image on another repository is a good backup strategy but does not prevent the original tag from being overwritten on the source DTR repository.
Concept tested. Docker Trusted Registry (DTR) immutable tags
Topics
#Docker Trusted Registry#Image immutability#Tag management#Registry features
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