The digest of an image being mirrored by oc-mirror could change due the compression algorithm being used by the containers/image (go mod used to mirror images in oc-mirror).

Changing the digest could impact oc-mirror a lot since it relies on the digest on several places during the flow (for example, in mirrorToDisk the digest is used to save artifacts that will be consumed in diskToMirror).

Run MirrorToDisk and DiskToMirror
    

With the following ImageSetConfiguration:

kind: ImageSetConfiguration
apiVersion: mirror.openshift.io/v2alpha1
mirror:
operators:
 - catalog: registry.redhat.io/redhat/redhat-operator-index@sha256:562445602e026dea6c695e7c551ceb2b1b9f7539c0bde95371b64259d060833b
packages:
 - name: aws-load-balancer-operator
 - name: 3scale-operator
 - name: node-observability-operator

1 - Run the mirror to disk
2 - Run the disk to mirror

2024/10/11 11:51:46  [ERROR]  : open /home/aguidi/go/src/github.com/aguidirh/oc-mirror/alex-tests/clid-247-main/working-dir/operator-images/redhat-operator-index/699ec1f7ad348e14e9f5f3ecb863cb4f5fd885b535d8111aa6c7dbcf0d46825b/index.json: no such file or directory 

Disk to mirror fails because the folder generated inside of the working-dir (during the mirrorToDisk) contains the digest number 562445602e026dea6c695e7c551ceb2b1b9f7539c0bde95371b64259d060833b but due the compression algorithm when calling the PUT in the local registry, the digest 699ec1f7ad348e14e9f5f3ecb863cb4f5fd885b535d8111aa6c7dbcf0d46825b is generated and added. 

During diskToMirror oc-mirror will try to find the folder with the digest of the compression and will not find it since the folder was created with the digest before the compression.

DiskToMirror should successfully work without errors.