mirror: copy cosign .sig OCI artifacts alongside release images#4779
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mirror: copy cosign .sig OCI artifacts alongside release images#4779
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shubhadapaithankar
requested review from
alcasim,
bennerv,
cadenmarchese,
hawkowl,
hlipsig,
jharrington22,
kevinobriendotca,
kimorris27,
mociarain,
mrWinston,
rogbas,
sankur-codes,
tiguelu,
tsatam,
tuxerrante,
ventifus,
wanghaoran1988 and
yjst2012
as code owners
The mirror pipeline copies release images and component images from quay.io to arosvc.azurecr.io but never copies the cosign .sig OCI artifacts (tagged as sha256-<digest>.sig). OCP 4.21 enforces cosign signature verification via ClusterImagePolicy for ocp-release pulls, so disconnected clusters that depend solely on arosvc fail with SignatureValidationFailed during z-stream upgrades. After each successful image copy, the worker now attempts to also copy the corresponding .sig artifact from the source registry. For digest-based references (component images), the digest is extracted from the reference string. For tag-based references (release images), the manifest is fetched to compute the digest. If a .sig artifact does not exist (older unsigned releases), the failure is logged at debug level and does not affect the overall mirror result. Fixes: ARO-26171
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/azp run ci |
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Azure Pipelines successfully started running 1 pipeline(s). |
Collaborator
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okay, it looks all references flowing through the mirror pipeline are digest-based, so please ignore my previous comment below: |
yjst2012
approved these changes
Apr 17, 2026
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Summary
Context
Incident: ITN-2026-00112
IcM: 780900379
Jira: ARO-26171
OCP 4.21 ships a ClusterImagePolicy that enforces cosign signature verification for all pulls of quay.io/openshift-release-dev/ocp-release. In disconnected ARO clusters that depend on �rosvc.azurecr.io, the mirror pipeline never copied .sig OCI artifacts, causing SignatureValidationFailed during z-stream upgrades within 4.21.x.
Test plan
epoFromReference, sigReference, digestFromReference