Merge pull request #38019 from chinmayi-chandrasekar/BZ1910284_mirroring_operator_catalog_REG_CREDS

BZ1910284: add clarification regarding REG_CREDS

Author: EricPonvelle

modules/olm-mirroring-catalog-colocated.adoc

@@ -40,6 +40,7 @@ $ oc adm catalog mirror \
 <1> Specify the index image for the catalog that you want to mirror. For example, this might be a pruned index image that you created previously, or one of the source index images for the default catalogs, such as `{index-image-pullspec}`.
 <2> Specify the target registry and namespace to mirror the Operator contents to, where `<namespace>` is any existing namespace on the registry. For example, you might create an `olm-mirror` namespace to push all mirrored content to.
 <3> Optional: If required, specify the location of your registry credentials file.
+`{REG_CREDS}` is required for `registry.redhat.io`.
 <4> Optional: If you do not want to configure trust for the target registry, add the `--insecure` flag.
 <5> Optional: Specify which platform and architecture of the index image to select when multiple variants are available. Images are passed as `'<platform>/<arch>[/<variant>]'`. This does not apply to images referenced by the index. Valid values are `linux/amd64`, `linux/ppc64le`, `linux/s390x`, and `.*`
 <6> Optional: Generate only the manifests required for mirroring, and do not actually mirror the image content to a registry. This option can be useful for reviewing what will be mirrored, and it allows you to make any changes to the mapping list if you require only a subset of packages. You can then use the `mapping.txt` file with the `oc image mirror` command to mirror the modified list of images in a later step. This flag is intended for only advanced selective mirroring of content from the catalog; the `opm index prune` command, if you used it previously to prune the index image, is suitable for most catalog management use cases.

modules/olm-mirroring-catalog-prereqs.adoc

@@ -21,7 +21,7 @@ endif::[]
 link:https://docs.docker.com/registry/spec/manifest-v2-2/[Docker v2-2].
 * Decide which namespace on your mirror registry you will use to store the mirrored Operator content. For example, you might create an `olm-mirror` namespace.
 * If your mirror registry does not have internet access, connect removable media to your workstation with unrestricted network access.
-* If you are working with private registries, set the `REG_CREDS` environment variable to the file path of your registry credentials for use in later steps. For example, for the `podman` CLI:
+* If you are working with private registries, including `registry.redhat.io`, set the `REG_CREDS` environment variable to the file path of your registry credentials for use in later steps. For example, for the `podman` CLI:
 +
 [source,terminal]
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