Having a better control of the ammount of images that the administrator of OCP is downloading in the mirroring process to the offline registry it becomes to be one of a key requirement. This control implies a better storage usage management of the offline registry. How to achieve this management we are going to discuss further.

The following list represents the prerequisites that needs to be fullfilled before proceeding with the first step:

  • OCPv4.10.X
  • Redhat Enterprise Linux/Rocky Linux/Fedora
  • Downloaded pull-secret.txt file
  • podman package available to the OS

Step 1. How to reduce the overall storage for upgrading a operator using oc-mirror cli:

If you dont mention the parameter full or full:true (default value) this will overwite the minVersion and maxVersion values, therefore you will download all the odf-operator images available in the stable-4.10 channel:

  • a example of how to perform a mirror config for the imageset-config.yaml:
---
apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  operators:
    - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.10
      targetName: 'rh-index'
      targetTag: v1-test
      full: true
      packages:
        - name: odf-operator
      packages:
        - name: odf-operator
          minVersion: '4.10.4'
          maxVersion: '4.10.4'
          channels:
                  - name: 'stable-4.10'

  • a example of the channel content for the registry.redhat.io/redhat/redhat-operator-index:v4.10:

    • odf-operator:
grpcurl -plaintext  INBACRNRDL0100.offline.oxtechnix.lan:50051 api.Registry.ListBundles | jq ' .packageName, .channelName, .bundlePath, .version'
...
"odf-operator"
"stable-4.10"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:dc4d9a53dea5573e3020ad5d1ea1018705b6be25294c722d29f57bd90564c58c"
"4.10.0"
"odf-operator"
"stable-4.10"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:bc2cac50a38866218646cb8b9af10cc8fa03cb01467878ebf412e783150350ea"
"4.10.1"
"odf-operator"
"stable-4.10"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:a00e90621b5a6f94abd890c9ffa1dd9703f213b6a418b49570f692fb85affafb"
"4.10.2"
"odf-operator"
"stable-4.10"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:0651850ea45cad985998ede7e625e22ae3ffc50442142fbe49eef558cffc81a0"
"4.10.3"
"odf-operator"
"stable-4.10"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:662ec108960703f41652ff47b49e6a509a52fe244d52891d320b821dd9521f55"
"4.10.4"
"odf-operator"
"stable-4.10"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:182d966cb488b188075d2ffd3f6451eec179429ac4bff55e2e26245049953a82"
"4.10.5"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:2231fc5ebf70c6165947bdc31f95b6deaa69f1efbd6c6194b457e2ad7bb10948"
"4.9.0"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:e712508135eb67c2598aabc65b8bbbce9a318b1812b2a02867db2e32dbfb290a"
"4.9.1"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:d7127d83b30998b3814f8c91759034b4f9ae527a827e0c896ef40279f5c418f9"
"4.9.10"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:192ef97f674aaaefe4519a09b0890216e956203750d4190a6d366e8aa5f1104f"
"4.9.2"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:e7b4f1d6c7ba12a0198f1ac36d8e6d51303021d25bfc8f289b9985e532b85a06"
"4.9.3"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:96d4fd806017ec3df272c56af8bbccde3d300b69fee2948ec542b0a2a5b17373"
"4.9.4"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:46437c6869986e4c394998b4db38bd19c8deee156c7ca02b33b3d336f5a08a8b"
"4.9.5"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:eb0eb013f819ab14eb1176e6f2ce7017fc2aaa2575a95fd02cd2aa0c4701b36b"
"4.9.6"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:b3e4af7ddab6dcd633cd0bf9fcbed57907fb4c60ef88c66e69d0fcbe86bfb9d7"
"4.9.7"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:887b396617fe70818b9c9cf5289988801f5125cbbee2f1e3a7d95f0c3e8fa672"
"4.9.8"
"odf-operator"
"stable-4.9"
"registry.redhat.io/odf4/odf-operator-bundle@sha256:552c35a9174b0b73781c38c859cbe17086ff28a2b088fd0f15b3793bc4bb26a4"
...

As you an see, the above imageset-config.yaml file will download all the container base images in the stable-4.10 channel of odf-operator, and this versions are the following: 4.10.0, 4.10.1, 4.10.2, 4.10.3, 4.10.4, 4.10.5. And in this way, you will required a additional disk space to host all the images.

In order to download only a specific odf-operator container base image you will need to use the following imageset-config.yaml configuration:

---
apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  operators:
    - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.10
      targetName: 'rh-index'
      targetTag: v1-test
      full: false
      packages:
        - name: odf-operator
      packages:
        - name: odf-operator
          minVersion: '4.10.4'
          maxVersion: '4.10.4'
          channels:
                  - name: 'stable-4.10'

As you an see, the above imageset-config.yaml file will download only the version 4.10.4 the container base images in the stable-4.10 channel of odf-operator. And in this way, you will optimise the disk space to host all the images.

Operator Name Channel Name Size Container base image versions downloaded Size compaction
odf-operator stable-4.10 25G 4.10.0, 4.10.1, 4.10.2, 4.10.3, 4.10.4, 4.10.5 -
odf-operator stable-4.10 6.3G 4.10.4 75%

In order to mirror from different channel versions, you will need to use the oc-mirror cli and define the imageset-config.yaml file as below:

---
apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  operators:
    - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.10
      targetName: 'rh-index'
      targetTag: v1-test
      full: true
      packages:
        - name: odf-operator
      packages:
        - name: odf-operator
          minVersion: '4.9.0'
          maxVersion: '4.10.4'
          channels:
                  - name: 'stable-4.9'
                  - name: 'stable-4.10'

In order to mirror specific versions, you will need to use the oc-mirror cli and define the imageset-config.yaml file as below:

---
apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  operators:
    - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.10
      targetName: 'rh-index'
      targetTag: v1-test
      full: false
      packages:
        - name: odf-operator
      packages:
        - name: odf-operator
          minVersion: '4.9.0'
          maxVersion: '4.10.4'
          channels:
                  - name: 'stable-4.9'
                  - name: 'stable-4.10'

In order to proceed with the mirroring process we splitted the process in two stages:

Stage number 1. Where we are downloading the specific packages locally to a tar file:

oc-mirror --config imageset-config.yaml file://archive

Stage number 2. Where we are uploading the content of the local tar file to local offline registry: Exporting the global variables:

export REGISTRY_NAME=INBACRNRDL0100.offline.oxtechnix.lan
export REGISTRY_NAMESPACE=olm-mirror

Upload the container base images to the Offline Host registry:

oc-mirror --from ./archive docker://${REGISTRY_NAME}:5000/${REGISTRY_NAMESPACE}

Once those two stages are completed without errors, we will obtain the ICSP yaml file and we are able to verify the content of the local offline registry, to do so, use the following command:

curl -X GET -u <username>:<password> https://$(hostname -f):5000/v2/_catalog --insecure | jq .

For the first imageset-config.yaml the Offline Registry content its the following:

curl -X GET -u <username>:<password> https://$(hostname -f):5000/v2/_catalog --insecure | jq .
{
  "repositories": [
    "olm-mirror/odf4/cephcsi-rhel8",
    "olm-mirror/odf4/mcg-core-rhel8",
    "olm-mirror/odf4/mcg-operator-bundle",
    "olm-mirror/odf4/mcg-rhel8-operator",
    "olm-mirror/odf4/ocs-must-gather-rhel8",
    "olm-mirror/odf4/ocs-operator-bundle",
    "olm-mirror/odf4/ocs-rhel8-operator",
    "olm-mirror/odf4/odf-console-rhel8",
    "olm-mirror/odf4/odf-csi-addons-operator-bundle",
    "olm-mirror/odf4/odf-csi-addons-rhel8-operator",
    "olm-mirror/odf4/odf-csi-addons-sidecar-rhel8",
    "olm-mirror/odf4/odf-operator-bundle",
    "olm-mirror/odf4/odf-rhel8-operator",
    "olm-mirror/odf4/rook-ceph-rhel8-operator",
    "olm-mirror/odf4/volume-replication-rhel8-operator",
    "olm-mirror/openshift4/ose-csi-external-attacher",
    "olm-mirror/openshift4/ose-csi-external-provisioner",
    "olm-mirror/openshift4/ose-csi-external-provisioner-rhel8",
    "olm-mirror/openshift4/ose-csi-external-resizer",
    "olm-mirror/openshift4/ose-csi-external-resizer-rhel8",
    "olm-mirror/openshift4/ose-csi-external-snapshotter",
    "olm-mirror/openshift4/ose-csi-external-snapshotter-rhel8",
    "olm-mirror/openshift4/ose-csi-node-driver-registrar",
    "olm-mirror/openshift4/ose-kube-rbac-proxy",
    "olm-mirror/redhat/rh-index",
    "olm-mirror/rhceph/rhceph-5-rhel8",
    "olm-mirror/rhel8/postgresql-12"
  ]
}

For the second imageset-config.yaml the Offline Registry content its the following:

curl -X GET -u <username>:<password> https://$(hostname -f):5000/v2/_catalog --insecure | jq .
{
  "repositories": [
    "olm-mirror/odf4/cephcsi-rhel8",
    "olm-mirror/odf4/mcg-core-rhel8",
    "olm-mirror/odf4/mcg-operator-bundle",
    "olm-mirror/odf4/mcg-rhel8-operator",
    "olm-mirror/odf4/ocs-must-gather-rhel8",
    "olm-mirror/odf4/ocs-operator-bundle",
    "olm-mirror/odf4/ocs-rhel8-operator",
    "olm-mirror/odf4/odf-console-rhel8",
    "olm-mirror/odf4/odf-csi-addons-operator-bundle",
    "olm-mirror/odf4/odf-csi-addons-rhel8-operator",
    "olm-mirror/odf4/odf-csi-addons-sidecar-rhel8",
    "olm-mirror/odf4/odf-operator-bundle",
    "olm-mirror/odf4/odf-rhel8-operator",
    "olm-mirror/odf4/rook-ceph-rhel8-operator",
    "olm-mirror/odf4/volume-replication-rhel8-operator",
    "olm-mirror/openshift4/ose-csi-external-attacher",
    "olm-mirror/openshift4/ose-csi-external-provisioner",
    "olm-mirror/openshift4/ose-csi-external-provisioner-rhel8",
    "olm-mirror/openshift4/ose-csi-external-resizer",
    "olm-mirror/openshift4/ose-csi-external-resizer-rhel8",
    "olm-mirror/openshift4/ose-csi-external-snapshotter",
    "olm-mirror/openshift4/ose-csi-external-snapshotter-rhel8",
    "olm-mirror/openshift4/ose-csi-node-driver-registrar",
    "olm-mirror/openshift4/ose-kube-rbac-proxy",
    "olm-mirror/redhat/rh-index",
    "olm-mirror/rhceph/rhceph-5-rhel8",
    "olm-mirror/rhel8/postgresql-12"
  ]
}

Below we will compare the size of the bundle of odf-operator

Operator Name Channel Name Size Container base image versions downloaded Size compaction
odf-operator stable-4.9 & stable-4.10 68G 4.10.0, 4.10.1, 4.10.2, 4.10.3, 4.10.4, -
      4.10.5 -
      4.9.0, 4.9.1, 4.9.2, 4.9.3, 4.9.4, 4.9.5,  
      4.9.6, 4.9.7, 4.9.8, 4.9.9, 4.9.10  
odf-operator stable-4.9 & stable-4.10 12G 4.9.0 & 4.10.4 82%

The content of the imageContentSourcePolicy.yaml :

---
apiVersion: operator.openshift.io/v1alpha1
kind: ImageContentSourcePolicy
metadata:
  labels:
    operators.openshift.org/catalog: "true"
  name: operator-0
spec:
  repositoryDigestMirrors:
  - mirrors:
    - inbacrnrdl0100.offline.oxtechnix.lan:5000/olm-mirror/rhceph
    source: registry.redhat.io/rhceph
  - mirrors:
    - inbacrnrdl0100.offline.oxtechnix.lan:5000/olm-mirror/odf4
    source: registry.redhat.io/odf4
  - mirrors:
    - inbacrnrdl0100.offline.oxtechnix.lan:5000/olm-mirror/openshift4
    source: registry.redhat.io/openshift4
  - mirrors:
    - inbacrnrdl0100.offline.oxtechnix.lan:5000/olm-mirror/redhat
    source: registry.redhat.io/redhat
  - mirrors:
    - inbacrnrdl0100.offline.oxtechnix.lan:5000/olm-mirror/rhel8
    source: registry.redhat.io/rhel8

and the content of the catalogSource-rh-index.yaml:

---
apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: rh-index
  namespace: openshift-marketplace
spec:
  image: inbacrnrdl0100.offline.oxtechnix.lan:5000/olm-mirror/redhat/rh-index:v1-test
  sourceType: grpc

A more detail overview its available here.

As a conclusion, we can observe that using the full: false parameter, the mirroring process its taking in consideration the minVersion and maxVersion parameter values and its considering only the mention container image versions. Proceeding in this way, the used storage for the mirroring its reduced considerable.