Description of problem:

When mirroring a pruned image for a restricted (airgap) cluster, oc adm catalog fails due to what seems like invalid path assumptions from tool.

[quicklab@master-0 mirror]$ oc adm catalog mirror file://local/index/mirror-ocp4/redhat-operator-index:v4.6 localhost:5000/mirror-ocp4 --insecure -a ../pullsecret
src image has index label for database path: /database/index.db
using database path mapping: /database/index.db:/tmp/982262084
wrote database to /tmp/982262084
using database at: /tmp/982262084/index.db
localhost:5000/
  mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index
    blobs:
      file://local/index/mirror-ocp4/redhat-operator-index sha256:74578e827b487178665e59cec95e17e6ff4bf6b996d8f3e508ddeffc3bfc4791 168B
      file://local/index/mirror-ocp4/redhat-operator-index sha256:572c5addd5bf044b6b734ce40380d032464410a096b6f0a82340f8149fd66ab6 3.475KiB
      file://local/index/mirror-ocp4/redhat-operator-index sha256:ffaff33cc5a472577be22b5ed0aa68ff11d97811f559f1258533f69c9e3c4a5d 2.169MiB
      file://local/index/mirror-ocp4/redhat-operator-index sha256:74782b667c7d97370a22aec902de10a0acbf19e545f0a770e1b7e37ab2b84774 2.766MiB
      file://local/index/mirror-ocp4/redhat-operator-index sha256:d793bf0b9363390be5ee2cf6f706c004378e848d741f4269b253b95146154e73 3.746MiB
      file://local/index/mirror-ocp4/redhat-operator-index sha256:f123f899a38e425da3487231bf5b60f19e0c5eed474aecd296c2f89abeb833c7 6.989MiB
      file://local/index/mirror-ocp4/redhat-operator-index sha256:5c1f3e8353d28d2f97a97304ee7ef8dc4d7bc4d028667ac20416fde26863b5f8 14.8MiB
    manifests:
      sha256:3f26884df7bb51fde3e5f9dd25477934b340d1c8f22aae253ba409658433eee4 -> v4.6
  stats: shared=0 unique=7 size=30.47MiB ratio=1.00

error: unable to retrieve source image file://local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-cluster-logging-operator manifest sha256:5aa8966f31e224cbd312c4058cec33805a0d66361eb79460823dbe453f791a76: open v2/local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-cluster-logging-operator/manifests/sha256:5aa8966f31e224cbd312c4058cec33805a0d66361eb79460823dbe453f791a76: no such file or directory
error: unable to retrieve source image file://local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-logging-fluentd manifest sha256:0e9b0002ea177e80861f5a8517ccf62e05535d6e4a4d48a905e6b329865e4229: open v2/local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-logging-fluentd/manifests/sha256:0e9b0002ea177e80861f5a8517ccf62e05535d6e4a4d48a905e6b329865e4229: no such file or directory
error: unable to retrieve source image file://local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-cluster-logging-operator-bundle manifest sha256:d52c96ee7197c9958501388258fd4a20f7c3ff243ce9e8d93503bcdbccc09c1c: open v2/local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-cluster-logging-operator-bundle/manifests/sha256:d52c96ee7197c9958501388258fd4a20f7c3ff243ce9e8d93503bcdbccc09c1c: no such file or directory
error: unable to retrieve source image file://local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-logging-curator5 manifest sha256:fccd7bb4bc56f31503c34dba25e99095747a1ee42c353b4279635e759a1b7685: open v2/local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-logging-curator5/manifests/sha256:fccd7bb4bc56f31503c34dba25e99095747a1ee42c353b4279635e759a1b7685: no such file or directory
phase 0:
  localhost:5000 mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index blobs=7 mounts=0 manifests=1 shared=0

info: Planning completed in 10ms
uploading: localhost:5000/mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index sha256:d793bf0b9363390be5ee2cf6f706c004378e848d741f4269b253b95146154e73 3.746MiB
uploading: localhost:5000/mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index sha256:f123f899a38e425da3487231bf5b60f19e0c5eed474aecd296c2f89abeb833c7 6.989MiB
uploading: localhost:5000/mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index sha256:5c1f3e8353d28d2f97a97304ee7ef8dc4d7bc4d028667ac20416fde26863b5f8 14.8MiB
uploading: localhost:5000/mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index sha256:74782b667c7d97370a22aec902de10a0acbf19e545f0a770e1b7e37ab2b84774 2.766MiB
uploading: localhost:5000/mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index sha256:ffaff33cc5a472577be22b5ed0aa68ff11d97811f559f1258533f69c9e3c4a5d 2.169MiB
sha256:3f26884df7bb51fde3e5f9dd25477934b340d1c8f22aae253ba409658433eee4 localhost:5000/mirror-ocp4/local-index-mirror-ocp4-redhat-operator-index:v4.6
info: Mirroring completed in 680ms (46.86MB/s)
error mirroring image: one or more errors occurred
no digest mapping available for file://local/index/mirror-ocp4/redhat-operator-index:v4.6, skip writing to ImageContentSourcePolicy
wrote mirroring manifests to manifests-index/mirror-ocp4/redhat-operator-index-1624035924

For some reason, the normal artifacts of the various operator images were downloaded w/ their original paths into the file:// location; however, when attempting to upload them into the mirror registry, it is appending their original locations to the location of the pruned image.  Example:

error: unable to retrieve source image file://local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-logging-curator5 manifest sha256:fccd7bb4bc56f31503c34dba25e99095747a1ee42c353b4279635e759a1b7685: open v2/local/index/mirror-ocp4/redhat-operator-index/openshift4/ose-logging-curator5/manifests/sha256:fccd7bb4bc56f31503c34dba25e99095747a1ee42c353b4279635e759a1b7685: no such file or directory

Here you can see that openshift4/ose-logging-curator5 which is the correct path under v2 is being appended to the namespace of the index mirror-ocp4/redhat-operator-index.

Version-Release number of selected component (if applicable):
oc client 4.6.0-202105290217.p0.git.5ab7b2b-5ab7b2b
opm {OpmVersion:"v1.14.3-34-gd0b49148", GitCommit:"d0b49148a4f476f1403c7b8fd262173789009484", BuildDate:"2021-05-29T03:52:37Z", GoOs:"linux", GoArch:"amd64"}

How reproducible:
always

Steps to Reproduce:

1. Create local registry

  podman pull docker.io/registry
  podman run -d -p 5000:5000 --restart always --name registry registry:2
  
2. Create pruned catalog
  
  opm index prune -f registry.redhat.io/redhat/redhat-operator-index:v4.6 -p cluster-logging -t master-0:5000/mirror-ocp4/redhat-operator-index:v4.6
  podman push master-0:5000/mirror-ocp4/redhat-operator-index:v4.6
  
3. Mirror pruned catalog
  
  oc adm catalog mirror localhost:5000/mirror-ocp4/redhat-operator-index:v4.6 file:///local/index -a ../pullsecret --insecure --filter-by-os=linux/amd64
  oc adm catalog mirror file://local/index/mirror-ocp4/redhat-operator-index:v4.6 localhost:5000/mirror-test2 --insecure -a ../pullsecret


NOTE: All was done by following: https://docs.openshift.com/container-platform/4.6/operators/admin/olm-restricted-networks.html

Actual results:
Unable to upload pruned registry

Expected results:
Able to upload pruned registry

Additional info:

I was unable to try using default operator index.  It is over 20GB is size and my medium was not that large.  I am currently assuming targeting the original operator index above would cause the same scenario.