Chapter 4. Mirroring images for a disconnected installation using the oc-mirror plugin
Running your cluster in a restricted network without direct internet connectivity is possible by installing the cluster from a mirrored set of OpenShift Container Platform container images in a private registry. This registry must be running at all times as long as the cluster is running. See the Prerequisites section for more information.
You can use the oc-mirror OpenShift CLI (oc
) plugin to mirror images to a mirror registry in your fully or partially disconnected environments. You must run oc-mirror from a system with internet connectivity in order to download the required images from the official Red Hat registries.
The following steps outline the high-level workflow on how to use the oc-mirror plugin to mirror images to a mirror registry:
- Create an image set configuration file.
Mirror the image set to the mirror registry by using one of the following methods:
- Mirror an image set directly to the mirror registry.
- Mirror an image set to disk, transfer the image set to the target environment, then upload the image set to the target mirror registry.
- Configure your cluster to use the resources generated by the oc-mirror plugin.
- Repeat these steps to update your mirror registry as necessary.
4.1. About the oc-mirror plugin
You can use the oc-mirror OpenShift CLI (oc
) plugin to mirror all required OpenShift Container Platform content and other images to your mirror registry by using a single tool. It provides the following features:
- Provides a centralized method to mirror OpenShift Container Platform releases, Operators, helm charts, and other images.
- Maintains update paths for OpenShift Container Platform and Operators.
- Uses a declarative image set configuration file to include only the OpenShift Container Platform releases, Operators, and images that your cluster needs.
- Performs incremental mirroring, which reduces the size of future image sets.
- Prunes images from the target mirror registry that were excluded from the image set configuration since the previous execution.
- Optionally generates supporting artifacts for OpenShift Update Service (OSUS) usage.
When using the oc-mirror plugin, you specify which content to mirror in an image set configuration file. In this YAML file, you can fine-tune the configuration to only include the OpenShift Container Platform releases and Operators that your cluster needs. This reduces the amount of data that you need to download and transfer. The oc-mirror plugin can also mirror arbitrary helm charts and additional container images to assist users in seamlessly synchronizing their workloads onto mirror registries.
The first time you run the oc-mirror plugin, it populates your mirror registry with the required content to perform your disconnected cluster installation or update. In order for your disconnected cluster to continue receiving updates, you must keep your mirror registry updated. To update your mirror registry, you run the oc-mirror plugin using the same configuration as the first time you ran it. The oc-mirror plugin references the metadata from the storage backend and only downloads what has been released since the last time you ran the tool. This provides update paths for OpenShift Container Platform and Operators and performs dependency resolution as required.
When using the oc-mirror CLI plugin to populate a mirror registry, any further updates to the mirror registry must be made using the oc-mirror tool.
4.2. oc-mirror compatibility and support
The oc-mirror plugin supports mirroring OpenShift Container Platform payload images and Operator catalogs for OpenShift Container Platform versions 4.10 and later.
Use the latest available version of the oc-mirror plugin regardless of which versions of OpenShift Container Platform you need to mirror.
If you used the Technology Preview OCI local catalogs feature for the oc-mirror plugin for OpenShift Container Platform 4.12, you can no longer use the OCI local catalogs feature of the oc-mirror plugin to copy a catalog locally and convert it to OCI format as a first step to mirroring to a fully disconnected cluster.
4.3. About the mirror registry
You can mirror the images that are required for OpenShift Container Platform installation and subsequent product updates to a container mirror registry that supports Docker v2-2, such as Red Hat Quay. If you do not have access to a large-scale container registry, you can use the mirror registry for Red Hat OpenShift, which is a small-scale container registry included with OpenShift Container Platform subscriptions.
Regardless of your chosen registry, the procedure to mirror content from Red Hat hosted sites on the internet to an isolated image registry is the same. After you mirror the content, you configure each cluster to retrieve this content from your mirror registry.
The OpenShift image registry cannot be used as the target registry because it does not support pushing without a tag, which is required during the mirroring process.
If choosing a container registry that is not the mirror registry for Red Hat OpenShift, it must be reachable by every machine in the clusters that you provision. If the registry is unreachable, installation, updating, or normal operations such as workload relocation might fail. For that reason, you must run mirror registries in a highly available way, and the mirror registries must at least match the production availability of your OpenShift Container Platform clusters.
When you populate your mirror registry with OpenShift Container Platform images, you can follow two scenarios. If you have a host that can access both the internet and your mirror registry, but not your cluster nodes, you can directly mirror the content from that machine. This process is referred to as connected mirroring. If you have no such host, you must mirror the images to a file system and then bring that host or removable media into your restricted environment. This process is referred to as disconnected mirroring.
For mirrored registries, to view the source of pulled images, you must review the Trying to access
log entry in the CRI-O logs. Other methods to view the image pull source, such as using the crictl images
command on a node, show the non-mirrored image name, even though the image is pulled from the mirrored location.
Red Hat does not test third party registries with OpenShift Container Platform.
Additional resources
- For information about viewing the CRI-O logs to view the image source, see Viewing the image pull source.
4.4. Prerequisites
You must have a container image registry that supports Docker v2-2 in the location that will host the OpenShift Container Platform cluster, such as Red Hat Quay.
NoteIf you use Red Hat Quay, you must use version 3.6 or later with the oc-mirror plugin. If you have an entitlement to Red Hat Quay, see the documentation on deploying Red Hat Quay for proof-of-concept purposes or by using the Red Hat Quay Operator. If you need additional assistance selecting and installing a registry, contact your sales representative or Red Hat Support.
If you do not already have an existing solution for a container image registry, subscribers of OpenShift Container Platform are provided a mirror registry for Red Hat OpenShift. The mirror registry for Red Hat OpenShift is included with your subscription and is a small-scale container registry that can be used to mirror the required container images of OpenShift Container Platform in disconnected installations.
4.5. Preparing your mirror hosts
Before you can use the oc-mirror plugin to mirror images, you must install the plugin and create a container image registry credentials file to allow the mirroring from Red Hat to your mirror.
4.5.1. Installing the oc-mirror OpenShift CLI plugin
To use the oc-mirror OpenShift CLI plugin to mirror registry images, you must install the plugin. If you are mirroring image sets in a fully disconnected environment, ensure that you install the oc-mirror plugin on the host with internet access and the host in the disconnected environment with access to the mirror registry.
Prerequisites
-
You have installed the OpenShift CLI (
oc
).
Procedure
Download the oc-mirror CLI plugin.
- Navigate to the Downloads page of the OpenShift Cluster Manager Hybrid Cloud Console.
- Under the OpenShift disconnected installation tools section, click Download for OpenShift Client (oc) mirror plugin and save the file.
Extract the archive:
$ tar xvzf oc-mirror.tar.gz
If necessary, update the plugin file to be executable:
$ chmod +x oc-mirror
NoteDo not rename the
oc-mirror
file.Install the oc-mirror CLI plugin by placing the file in your
PATH
, for example,/usr/local/bin
:$ sudo mv oc-mirror /usr/local/bin/.
Verification
Run
oc mirror help
to verify that the plugin was successfully installed:$ oc mirror help
Additional resources
4.5.2. Configuring credentials that allow images to be mirrored
Create a container image registry credentials file that allows mirroring images from Red Hat to your mirror.
Do not use this image registry credentials file as the pull secret when you install a cluster. If you provide this file when you install cluster, all of the machines in the cluster will have write access to your mirror registry.
This process requires that you have write access to a container image registry on the mirror registry and adds the credentials to a registry pull secret.
Prerequisites
- You configured a mirror registry to use in your disconnected environment.
- You identified an image repository location on your mirror registry to mirror images into.
- You provisioned a mirror registry account that allows images to be uploaded to that image repository.
Procedure
Complete the following steps on the installation host:
-
Download your
registry.redhat.io
pull secret from the Red Hat OpenShift Cluster Manager. Make a copy of your pull secret in JSON format:
$ cat ./pull-secret | jq . > <path>/<pull_secret_file_in_json> 1
- 1
- Specify the path to the folder to store the pull secret in and a name for the JSON file that you create.
The contents of the file resemble the following example:
{ "auths": { "cloud.openshift.com": { "auth": "b3BlbnNo...", "email": "you@example.com" }, "quay.io": { "auth": "b3BlbnNo...", "email": "you@example.com" }, "registry.connect.redhat.com": { "auth": "NTE3Njg5Nj...", "email": "you@example.com" }, "registry.redhat.io": { "auth": "NTE3Njg5Nj...", "email": "you@example.com" } } }
Save the file as either
~/.docker/config.json
or$XDG_RUNTIME_DIR/containers/auth.json
:If the
.docker
or$XDG_RUNTIME_DIR/containers
directories do not exist, create one by entering the following command:$ mkdir -p <directory_name>
Where
<directory_name>
is either~/.docker
or$XDG_RUNTIME_DIR/containers
.Copy the pull secret to the appropriate directory by entering the following command:
$ cp <path>/<pull_secret_file_in_json> <directory_name>/<auth_file>
Where
<directory_name>
is either~/.docker
or$XDG_RUNTIME_DIR/containers
, and<auth_file>
is eitherconfig.json
orauth.json
.
Generate the base64-encoded user name and password or token for your mirror registry:
$ echo -n '<user_name>:<password>' | base64 -w0 1 BGVtbYk3ZHAtqXs=
- 1
- For
<user_name>
and<password>
, specify the user name and password that you configured for your registry.
Edit the JSON file and add a section that describes your registry to it:
"auths": { "<mirror_registry>": { 1 "auth": "<credentials>", 2 "email": "you@example.com" } },
The file resembles the following example:
{ "auths": { "registry.example.com": { "auth": "BGVtbYk3ZHAtqXs=", "email": "you@example.com" }, "cloud.openshift.com": { "auth": "b3BlbnNo...", "email": "you@example.com" }, "quay.io": { "auth": "b3BlbnNo...", "email": "you@example.com" }, "registry.connect.redhat.com": { "auth": "NTE3Njg5Nj...", "email": "you@example.com" }, "registry.redhat.io": { "auth": "NTE3Njg5Nj...", "email": "you@example.com" } } }
4.6. Creating the image set configuration
Before you can use the oc-mirror plugin to mirror image sets, you must create an image set configuration file. This image set configuration file defines which OpenShift Container Platform releases, Operators, and other images to mirror, along with other configuration settings for the oc-mirror plugin.
You must specify a storage backend in the image set configuration file. This storage backend can be a local directory or a registry that supports Docker v2-2. The oc-mirror plugin stores metadata in this storage backend during image set creation.
Do not delete or modify the metadata that is generated by the oc-mirror plugin. You must use the same storage backend every time you run the oc-mirror plugin for the same mirror registry.
Prerequisites
- You have created a container image registry credentials file. For instructions, see Configuring credentials that allow images to be mirrored.
Procedure
Use the
oc mirror init
command to create a template for the image set configuration and save it to a file calledimageset-config.yaml
:$ oc mirror init --registry example.com/mirror/oc-mirror-metadata > imageset-config.yaml 1
- 1
- Replace
example.com/mirror/oc-mirror-metadata
with the location of your registry for the storage backend.
Edit the file and adjust the settings as necessary:
kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 archiveSize: 4 1 storageConfig: 2 registry: imageURL: example.com/mirror/oc-mirror-metadata 3 skipTLS: false mirror: platform: channels: - name: stable-4.13 4 type: ocp graph: true 5 operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 6 packages: - name: serverless-operator 7 channels: - name: stable 8 additionalImages: - name: registry.redhat.io/ubi9/ubi:latest 9 helm: {}
- 1
- Add
archiveSize
to set the maximum size, in GiB, of each file within the image set. - 2
- Set the back-end location to save the image set metadata to. This location can be a registry or local directory. It is required to specify
storageConfig
values. - 3
- Set the registry URL for the storage backend.
- 4
- Set the channel to retrieve the OpenShift Container Platform images from.
- 5
- Add
graph: true
to build and push the graph-data image to the mirror registry. The graph-data image is required to create OpenShift Update Service (OSUS). Thegraph: true
field also generates theUpdateService
custom resource manifest. Theoc
command-line interface (CLI) can use theUpdateService
custom resource manifest to create OSUS. For more information, see About the OpenShift Update Service. - 6
- Set the Operator catalog to retrieve the OpenShift Container Platform images from.
- 7
- Specify only certain Operator packages to include in the image set. Remove this field to retrieve all packages in the catalog.
- 8
- Specify only certain channels of the Operator packages to include in the image set. You must always include the default channel for the Operator package even if you do not use the bundles in that channel. You can find the default channel by running the following command:
oc mirror list operators --catalog=<catalog_name> --package=<package_name>
. - 9
- Specify any additional images to include in image set.
NoteThe
graph: true
field also mirrors theubi-micro
image along with other mirrored images.When upgrading OpenShift Container Platform Extended Update Support (EUS) versions, an intermediate version might be required between the current and target versions. For example, if the current version is
4.14
and target version is4.16
, you might need to include a version such as4.15.8
in theImageSetConfiguration
when using the oc-mirror plugin v1.The oc-mirror plugin v1 might not always detect this automatically, so check the Cincinnati graph web page to confirm any required intermediate versions and add them manually to your configuration.
See Image set configuration parameters for the full list of parameters and Image set configuration examples for various mirroring use cases.
Save the updated file.
This image set configuration file is required by the
oc mirror
command when mirroring content.
4.7. Mirroring an image set to a mirror registry
You can use the oc-mirror CLI plugin to mirror images to a mirror registry in a partially disconnected environment or in a fully disconnected environment.
These procedures assume that you already have your mirror registry set up.
4.7.1. Mirroring an image set in a partially disconnected environment
In a partially disconnected environment, you can mirror an image set directly to the target mirror registry.
4.7.1.1. Mirroring from mirror to mirror
You can use the oc-mirror plugin to mirror an image set directly to a target mirror registry that is accessible during image set creation.
You are required to specify a storage backend in the image set configuration file. This storage backend can be a local directory or a Docker v2 registry. The oc-mirror plugin stores metadata in this storage backend during image set creation.
Do not delete or modify the metadata that is generated by the oc-mirror plugin. You must use the same storage backend every time you run the oc-mirror plugin for the same mirror registry.
Prerequisites
- You have access to the internet to obtain the necessary container images.
-
You have installed the OpenShift CLI (
oc
). -
You have installed the
oc-mirror
CLI plugin. - You have created the image set configuration file.
Procedure
Run the
oc mirror
command to mirror the images from the specified image set configuration to a specified registry:$ oc mirror --config=./imageset-config.yaml \1 docker://registry.example:5000 2
- 1
- Pass in the image set configuration file that was created. This procedure assumes that it is named
imageset-config.yaml
. - 2
- Specify the registry to mirror the image set file to. The registry must start with
docker://
. If you specify a top-level namespace for the mirror registry, you must also use this same namespace on subsequent executions.
Verification
-
Navigate into the
oc-mirror-workspace/
directory that was generated. -
Navigate into the results directory, for example,
results-1639608409/
. -
Verify that YAML files are present for the
ImageContentSourcePolicy
andCatalogSource
resources.
Next steps
- Configure your cluster to use the resources generated by oc-mirror.
Troubleshooting
4.7.2. Mirroring an image set in a fully disconnected environment
To mirror an image set in a fully disconnected environment, you must first mirror the image set to disk, then mirror the image set file on disk to a mirror.
4.7.2.1. Mirroring from mirror to disk
You can use the oc-mirror plugin to generate an image set and save the contents to disk. The generated image set can then be transferred to the disconnected environment and mirrored to the target registry.
Depending on the configuration specified in the image set configuration file, using oc-mirror to mirror images might download several hundreds of gigabytes of data to disk.
The initial image set download when you populate the mirror registry is often the largest. Because you only download the images that changed since the last time you ran the command, when you run the oc-mirror plugin again, the generated image set is often smaller.
You are required to specify a storage backend in the image set configuration file. This storage backend can be a local directory or a docker v2 registry. The oc-mirror plugin stores metadata in this storage backend during image set creation.
Do not delete or modify the metadata that is generated by the oc-mirror plugin. You must use the same storage backend every time you run the oc-mirror plugin for the same mirror registry.
Prerequisites
- You have access to the internet to obtain the necessary container images.
-
You have installed the OpenShift CLI (
oc
). -
You have installed the
oc-mirror
CLI plugin. - You have created the image set configuration file.
Procedure
Run the
oc mirror
command to mirror the images from the specified image set configuration to disk:$ oc mirror --config=./imageset-config.yaml \1 file://<path_to_output_directory> 2
Verification
Navigate to your output directory:
$ cd <path_to_output_directory>
Verify that an image set
.tar
file was created:$ ls
Example output
mirror_seq1_000000.tar
Next steps
- Transfer the image set .tar file to the disconnected environment.
Troubleshooting
4.7.2.2. Mirroring from disk to mirror
You can use the oc-mirror plugin to mirror the contents of a generated image set to the target mirror registry.
Prerequisites
-
You have installed the OpenShift CLI (
oc
) in the disconnected environment. -
You have installed the
oc-mirror
CLI plugin in the disconnected environment. -
You have generated the image set file by using the
oc mirror
command. - You have transferred the image set file to the disconnected environment.
Procedure
Run the
oc mirror
command to process the image set file on disk and mirror the contents to a target mirror registry:$ oc mirror --from=./mirror_seq1_000000.tar \1 docker://registry.example:5000 2
- 1
- Pass in the image set .tar file to mirror, named
mirror_seq1_000000.tar
in this example. If anarchiveSize
value was specified in the image set configuration file, the image set might be broken up into multiple .tar files. In this situation, you can pass in a directory that contains the image set .tar files. - 2
- Specify the registry to mirror the image set file to. The registry must start with
docker://
. If you specify a top-level namespace for the mirror registry, you must also use this same namespace on subsequent executions.
This command updates the mirror registry with the image set and generates the
ImageContentSourcePolicy
andCatalogSource
resources.
Verification
-
Navigate into the
oc-mirror-workspace/
directory that was generated. -
Navigate into the results directory, for example,
results-1639608409/
. -
Verify that YAML files are present for the
ImageContentSourcePolicy
andCatalogSource
resources.
Next steps
- Configure your cluster to use the resources generated by oc-mirror.
Troubleshooting
4.8. Configuring your cluster to use the resources generated by oc-mirror
After you have mirrored your image set to the mirror registry, you must apply the generated ImageContentSourcePolicy
, CatalogSource
, and release image signature resources into the cluster.
The ImageContentSourcePolicy
resource associates the mirror registry with the source registry and redirects image pull requests from the online registries to the mirror registry. The CatalogSource
resource is used by Operator Lifecycle Manager (OLM) to retrieve information about the available Operators in the mirror registry. The release image signatures are used to verify the mirrored release images.
Prerequisites
- You have mirrored the image set to the registry mirror in the disconnected environment.
-
You have access to the cluster as a user with the
cluster-admin
role.
Procedure
-
Log in to the OpenShift CLI as a user with the
cluster-admin
role. Apply the YAML files from the results directory to the cluster by running the following command:
$ oc apply -f ./oc-mirror-workspace/results-1639608409/
If you mirrored release images, apply the release image signatures to the cluster by running the following command:
$ oc apply -f ./oc-mirror-workspace/results-1639608409/release-signatures/
NoteIf you are mirroring Operators instead of clusters, you do not need to run
$ oc apply -f ./oc-mirror-workspace/results-1639608409/release-signatures/
. Running that command will return an error, as there are no release image signatures to apply.
Verification
Verify that the
ImageContentSourcePolicy
resources were successfully installed by running the following command:$ oc get imagecontentsourcepolicy
Verify that the
CatalogSource
resources were successfully installed by running the following command:$ oc get catalogsource -n openshift-marketplace
4.9. Keeping your mirror registry content updated
After your target mirror registry is populated with the initial image set, be sure to update it regularly so that it has the latest content. You can optionally set up a cron job, if possible, so that the mirror registry is updated on a regular basis.
Ensure that you update your image set configuration to add or remove OpenShift Container Platform and Operator releases as necessary. Any images that are removed are pruned from the mirror registry.
4.9.1. About updating your mirror registry content
When you run the oc-mirror plugin again, it generates an image set that only contains new and updated images since the previous execution. Because it only pulls in the differences since the previous image set was created, the generated image set is often smaller and faster to process than the initial image set.
Generated image sets are sequential and must be pushed to the target mirror registry in order. You can derive the sequence number from the file name of the generated image set archive file.
Adding new and updated images
Depending on the settings in your image set configuration, future executions of oc-mirror can mirror additional new and updated images. Review the settings in your image set configuration to ensure that you are retrieving new versions as necessary. For example, you can set the minimum and maximum versions of Operators to mirror if you want to restrict to specific versions. Alternatively, you can set the minimum version as a starting point to mirror, but keep the version range open so you keep receiving new Operator versions on future executions of oc-mirror. Omitting any minimum or maximum version gives you the full version history of an Operator in a channel. Omitting explicitly named channels gives you all releases in all channels of the specified Operator. Omitting any named Operator gives you the entire catalog of all Operators and all their versions ever released.
All these constraints and conditions are evaluated against the publicly released content by Red Hat on every invocation of oc-mirror. This way, it automatically picks up new releases and entirely new Operators. Constraints can be specified by only listing a desired set of Operators, which will not automatically add other newly released Operators into the mirror set. You can also specify a particular release channel, which limits mirroring to just this channel and not any new channels that have been added. This is important for Operator products, such as Red Hat Quay, that use different release channels for their minor releases. Lastly, you can specify a maximum version of a particular Operator, which causes the tool to only mirror the specified version range so that you do not automatically get any newer releases past the maximum version mirrored. In all these cases, you must update the image set configuration file to broaden the scope of the mirroring of Operators to get other Operators, new channels, and newer versions of Operators to be available in your target registry.
It is recommended to align constraints like channel specification or version ranges with the release strategy that a particular Operator has chosen. For example, when the Operator uses a stable
channel, you should restrict mirroring to that channel and potentially a minimum version to find the right balance between download volume and getting stable updates regularly. If the Operator chooses a release version channel scheme, for example stable-3.7
, you should mirror all releases in that channel. This allows you to keep receiving patch versions of the Operator, for example 3.7.1
. You can also regularly adjust the image set configuration to add channels for new product releases, for example stable-3.8
.
Pruning images
Images are pruned automatically from the target mirror registry if they are no longer included in the latest image set that was generated and mirrored. This allows you to easily manage and clean up unneeded content and reclaim storage resources.
If there are OpenShift Container Platform releases or Operator versions that you no longer need, you can modify your image set configuration to exclude them, and they will be pruned from the mirror registry upon mirroring. This can be done by adjusting a minimum or maximum version range setting per Operator in the image set configuration file or by deleting the Operator from the list of Operators to mirror from the catalog. You can also remove entire Operator catalogs or entire OpenShift Container Platform releases from the configuration file.
If there are no new or updated images to mirror, the excluded images are not pruned from the target mirror registry. Additionally, if an Operator publisher removes an Operator version from a channel, the removed versions are pruned from the target mirror registry.
To disable automatic pruning of images from the target mirror registry, pass the --skip-pruning
flag to the oc mirror
command.
4.9.2. Updating your mirror registry content
After you publish the initial image set to the mirror registry, you can use the oc-mirror plugin to keep your disconnected clusters updated.
Depending on your image set configuration, oc-mirror automatically detects newer releases of OpenShift Container Platform and your selected Operators that have been released after you completed the initial mirror. It is recommended to run oc-mirror at regular intervals, for example in a nightly cron job, to receive product and security updates on a timely basis.
Prerequisites
- You have used the oc-mirror plugin to mirror the initial image set to your mirror registry.
You have access to the storage backend that was used for the initial execution of the oc-mirror plugin.
NoteYou must use the same storage backend as the initial execution of oc-mirror for the same mirror registry. Do not delete or modify the metadata image that is generated by the oc-mirror plugin.
Procedure
- If necessary, update your image set configuration file to pick up new OpenShift Container Platform and Operator versions. See Image set configuration examples for example mirroring use cases.
Follow the same steps that you used to mirror your initial image set to the mirror registry. For instructions, see Mirroring an image set in a partially disconnected environment or Mirroring an image set in a fully disconnected environment.
Important- You must provide the same storage backend so that only a differential image set is created and mirrored.
- If you specified a top-level namespace for the mirror registry during the initial image set creation, then you must use this same namespace every time you run the oc-mirror plugin for the same mirror registry.
- Configure your cluster to use the resources generated by oc-mirror.
4.10. Performing a dry run
You can use oc-mirror to perform a dry run, without actually mirroring any images. This allows you to review the list of images that would be mirrored, as well as any images that would be pruned from the mirror registry. It also allows you to catch any errors with your image set configuration early or use the generated list of images with other tools to carry out the mirroring operation.
Prerequisites
- You have access to the internet to obtain the necessary container images.
-
You have installed the OpenShift CLI (
oc
). -
You have installed the
oc-mirror
CLI plugin. - You have created the image set configuration file.
Procedure
Run the
oc mirror
command with the--dry-run
flag to perform a dry run:$ oc mirror --config=./imageset-config.yaml \1 docker://registry.example:5000 \2 --dry-run 3
- 1
- Pass in the image set configuration file that was created. This procedure assumes that it is named
imageset-config.yaml
. - 2
- Specify the mirror registry. Nothing is mirrored to this registry as long as you use the
--dry-run
flag. - 3
- Use the
--dry-run
flag to generate the dry run artifacts and not an actual image set file.
Example output
Checking push permissions for registry.example:5000 Creating directory: oc-mirror-workspace/src/publish Creating directory: oc-mirror-workspace/src/v2 Creating directory: oc-mirror-workspace/src/charts Creating directory: oc-mirror-workspace/src/release-signatures No metadata detected, creating new workspace wrote mirroring manifests to oc-mirror-workspace/operators.1658342351/manifests-redhat-operator-index ... info: Planning completed in 31.48s info: Dry run complete Writing image mapping to oc-mirror-workspace/mapping.txt
Navigate into the workspace directory that was generated:
$ cd oc-mirror-workspace/
Review the
mapping.txt
file that was generated.This file contains a list of all images that would be mirrored.
Review the
pruning-plan.json
file that was generated.This file contains a list of all images that would be pruned from the mirror registry when the image set is published.
NoteThe
pruning-plan.json
file is only generated if your oc-mirror command points to your mirror registry and there are images to be pruned.
4.11. Including local OCI Operator catalogs
While mirroring OpenShift Container Platform releases, Operator catalogs, and additional images from a registry to a partially disconnected cluster, you can include Operator catalog images from a local file-based catalog on disk. The local catalog must be in the Open Container Initiative (OCI) format.
The local catalog and its contents are mirrored to your target mirror registry based on the filtering information in the image set configuration file.
When mirroring local OCI catalogs, any OpenShift Container Platform releases or additional images that you want to mirror along with the local OCI-formatted catalog must be pulled from a registry.
You cannot mirror OCI catalogs along with an oc-mirror image set file on disk.
One example use case for using the OCI feature is if you have a CI/CD system building an OCI catalog to a location on disk, and you want to mirror that OCI catalog along with an OpenShift Container Platform release to your mirror registry.
If you used the Technology Preview OCI local catalogs feature for the oc-mirror plugin for OpenShift Container Platform 4.12, you can no longer use the OCI local catalogs feature of the oc-mirror plugin to copy a catalog locally and convert it to OCI format as a first step to mirroring to a fully disconnected cluster.
Prerequisites
- You have access to the internet to obtain the necessary container images.
-
You have installed the OpenShift CLI (
oc
). -
You have installed the
oc-mirror
CLI plugin.
Procedure
Create the image set configuration file and adjust the settings as necessary.
The following example image set configuration mirrors an OCI catalog on disk along with an OpenShift Container Platform release and a UBI image from
registry.redhat.io
.kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 storageConfig: local: path: /home/user/metadata 1 mirror: platform: channels: - name: stable-4.13 2 type: ocp graph: false operators: - catalog: oci:///home/user/oc-mirror/my-oci-catalog 3 targetCatalog: my-namespace/redhat-operator-index 4 packages: - name: aws-load-balancer-operator - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 5 packages: - name: rhacs-operator additionalImages: - name: registry.redhat.io/ubi9/ubi:latest 6
- 1
- Set the back-end location to save the image set metadata to. This location can be a registry or local directory. It is required to specify
storageConfig
values. - 2
- Optionally, include an OpenShift Container Platform release to mirror from
registry.redhat.io
. - 3
- Specify the absolute path to the location of the OCI catalog on disk. The path must start with
oci://
when using the OCI feature. - 4
- Optionally, specify an alternative namespace and name to mirror the catalog as.
- 5
- Optionally, specify additional Operator catalogs to pull from a registry.
- 6
- Optionally, specify additional images to pull from a registry.
Run the
oc mirror
command to mirror the OCI catalog to a target mirror registry:$ oc mirror --config=./imageset-config.yaml \ 1 --include-local-oci-catalogs 2 docker://registry.example:5000 3
- 1
- Pass in the image set configuration file. This procedure assumes that it is named
imageset-config.yaml
. - 2
- Use the
--include-local-oci-catalogs
flag to enable mirroring local OCI catalogs along with other remote content. - 3
- Specify the registry to mirror the content to. The registry must start with
docker://
. If you specify a top-level namespace for the mirror registry, you must also use this same namespace on subsequent executions.
Optionally, you can specify other flags to adjust the behavior of the OCI feature:
--oci-insecure-signature-policy
- Do not push signatures to the target mirror registry.
--oci-registries-config
Specify the path to a TOML-formatted
registries.conf
file. You can use this to mirror from a different registry, such as a pre-production location for testing, without having to change the image set configuration file. This flag only affects local OCI catalogs, not any other mirrored content.Example registries.conf file
[[registry]] location = "registry.redhat.io:5000" insecure = false blocked = false mirror-by-digest-only = true prefix = "" [[registry.mirror]] location = "preprod-registry.example.com" insecure = false
Next steps
- Configure your cluster to use the resources generated by oc-mirror.
Additional resources
4.12. Image set configuration parameters
The oc-mirror plugin requires an image set configuration file that defines what images to mirror. The following table lists the available parameters for the ImageSetConfiguration
resource.
Parameter | Description | Values |
---|---|---|
|
The API version for the |
String. For example: |
| The maximum size, in GiB, of each archive file within the image set. |
Integer. For example: |
| The configuration of the image set. | Object |
| The additional images configuration of the image set. | Array of objects. For example: additionalImages: - name: registry.redhat.io/ubi8/ubi:latest |
| The tag or digest of the image to mirror. |
String. For example: |
| The full tag, digest, or pattern of images to block from mirroring. |
Array of strings. For example: |
| The helm configuration of the image set. Note that the oc-mirror plugin supports only helm charts that do not require user input when rendered. | Object |
| The local helm charts to mirror. | Array of objects. For example: local: - name: podinfo path: /test/podinfo-5.0.0.tar.gz |
| The name of the local helm chart to mirror. |
String. For example: |
| The path of the local helm chart to mirror. |
String. For example: |
| The remote helm repositories to mirror from. | Array of objects. For example: repositories: - name: podinfo url: https://example.github.io/podinfo charts: - name: podinfo version: 5.0.0 |
| The name of the helm repository to mirror from. |
String. For example: |
| The URL of the helm repository to mirror from. |
String. For example: |
| The remote helm charts to mirror. | Array of objects. |
| The name of the helm chart to mirror. |
String. For example: |
| The version of the named helm chart to mirror. |
String. For example: |
| The Operators configuration of the image set. | Array of objects. For example: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 packages: - name: elasticsearch-operator minVersion: '2.4.0' |
| The Operator catalog to include in the image set. |
String. For example: |
|
When |
Boolean. The default value is |
| The Operator packages configuration. | Array of objects. For example: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 packages: - name: elasticsearch-operator minVersion: '5.2.3-31' |
| The Operator package name to include in the image set |
String. For example: |
| The Operator package channel configuration. | Object |
| The Operator channel name, unique within a package, to include in the image set. |
String. For example: |
| The highest version of the Operator mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
| The name of the minimum bundle to include, plus all bundles in the upgrade graph to the channel head. Set this field only if the named bundle has no semantic version metadata. |
String. For example: |
| The lowest version of the Operator to mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
| The highest version of the Operator to mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
| The lowest version of the Operator to mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
|
If |
Boolean. The default value is |
| An alternative name and optional namespace hierarchy to mirror the referenced catalog as. |
String. For example: |
| An alternative name to mirror the referenced catalog as.
The |
String. For example: |
|
An alternative tag to append to the |
String. For example: |
| The platform configuration of the image set. | Object |
| The architecture of the platform release payload to mirror. | Array of strings. For example: architectures: - amd64 - arm64 |
| The platform channel configuration of the image set. | Array of objects. For example: channels: - name: stable-4.10 - name: stable-4.13 |
|
When |
Boolean. The default value is |
| The name of the release channel. |
String. For example: |
| The minimum version of the referenced platform to be mirrored. |
String. For example: |
| The highest version of the referenced platform to be mirrored. |
String. For example: |
| Toggles shortest path mirroring or full range mirroring. |
Boolean. The default value is |
| The type of the platform to be mirrored. |
String. For example: |
| Indicates whether the OSUS graph is added to the image set and subsequently published to the mirror. |
Boolean. The default value is |
| The back-end configuration of the image set. | Object |
| The local back-end configuration of the image set. | Object |
| The path of the directory to contain the image set metadata. |
String. For example: |
| The registry back-end configuration of the image set. | Object |
| The back-end registry URI. Can optionally include a namespace reference in the URI. |
String. For example: |
| Optionally skip TLS verification of the referenced back-end registry. |
Boolean. The default value is |
Using the the minVersion
and maxVersion
properties to filter for a specific Operator version range can result in a multiple channel heads error. The error message will state that there are multiple channel heads
. This is because when the filter is applied, the update graph of the operator is truncated.
The Operator Lifecycle Manager requires that every operator channel contains versions that form an update graph with exactly one end point, that is, the latest version of the operator. When applying the filter range that graph can turn into two or more separate graphs or a graph that has more than one end point.
To avoid this error, do not filter out the latest version of an operator. If you still run into the error, depending on the operator, either the maxVersion
property needs to be increased or the minVersion
property needs to be decreased. Because every operator graph can be different, you might need to adjust these values, according to the procedure, until the error is gone.
4.13. Image set configuration examples
The following ImageSetConfiguration
file examples show the configuration for various mirroring use cases.
Use case: Including the shortest OpenShift Container Platform upgrade path
The following ImageSetConfiguration
file uses a local storage backend and includes all OpenShift Container Platform versions along the shortest upgrade path from the minimum version of 4.11.37
to the maximum version of 4.12.15
.
Example ImageSetConfiguration
file
apiVersion: mirror.openshift.io/v1alpha2 kind: ImageSetConfiguration storageConfig: local: path: /home/user/metadata mirror: platform: channels: - name: stable-4.12 minVersion: 4.11.37 maxVersion: 4.12.15 shortestPath: true
Use case: Including all versions of OpenShift Container Platform from a minimum to the latest
The following ImageSetConfiguration
file uses a registry storage backend and includes all OpenShift Container Platform versions starting at a minimum version of 4.10.10
to the latest version in the channel.
On every invocation of oc-mirror with this image set configuration, the latest release of the stable-4.10
channel is evaluated, so running oc-mirror at regular intervals ensures that you automatically receive the latest releases of OpenShift Container Platform images.
Example ImageSetConfiguration
file
apiVersion: mirror.openshift.io/v1alpha2 kind: ImageSetConfiguration storageConfig: registry: imageURL: example.com/mirror/oc-mirror-metadata skipTLS: false mirror: platform: channels: - name: stable-4.10 minVersion: 4.10.10
Use case: Including Operator versions from a minimum to the latest
The following ImageSetConfiguration
file uses a local storage backend and includes only the Red Hat Advanced Cluster Security for Kubernetes Operator, versions starting at 4.0.1 and later in the stable
channel.
When you specify a minimum or maximum version range, you might not receive all Operator versions in that range.
By default, oc-mirror excludes any versions that are skipped or replaced by a newer version in the Operator Lifecycle Manager (OLM) specification. Operator versions that are skipped might be affected by a CVE or contain bugs. Use a newer version instead. For more information on skipped and replaced versions, see Creating an update graph with OLM.
To receive all Operator versions in a specified range, you can set the mirror.operators.full
field to true
.
Example ImageSetConfiguration
file
apiVersion: mirror.openshift.io/v1alpha2 kind: ImageSetConfiguration storageConfig: local: path: /home/user/metadata mirror: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 packages: - name: rhacs-operator channels: - name: stable minVersion: 4.0.1
To specify a maximum version instead of the latest, set the mirror.operators.packages.channels.maxVersion
field.
Use case: Including the Nutanix CSI Operator
The following ImageSetConfiguration
file uses a local storage backend and includes the Nutanix CSI Operator, the OpenShift Update Service (OSUS) graph image, and an additional Red Hat Universal Base Image (UBI).
Example ImageSetConfiguration
file
kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 storageConfig: registry: imageURL: mylocalregistry/ocp-mirror/openshift4 skipTLS: false mirror: platform: channels: - name: stable-4.11 type: ocp graph: true operators: - catalog: registry.redhat.io/redhat/certified-operator-index:v4.13 packages: - name: nutanixcsioperator channels: - name: stable additionalImages: - name: registry.redhat.io/ubi9/ubi:latest
Use case: Including the default Operator channel
The following ImageSetConfiguration
file includes the stable-5.7
and stable
channels for the OpenShift Elasticsearch Operator. Even if only the packages from the stable-5.7
channel are needed, the stable
channel must also be included in the ImageSetConfiguration
file, because it is the default channel for the Operator. You must always include the default channel for the Operator package even if you do not use the bundles in that channel.
You can find the default channel by running the following command: oc mirror list operators --catalog=<catalog_name> --package=<package_name>
.
Example ImageSetConfiguration
file
apiVersion: mirror.openshift.io/v1alpha2 kind: ImageSetConfiguration storageConfig: registry: imageURL: example.com/mirror/oc-mirror-metadata skipTLS: false mirror: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 packages: - name: elasticsearch-operator channels: - name: stable-5.7 - name: stable
Use case: Including an entire catalog (all versions)
The following ImageSetConfiguration
file sets the mirror.operators.full
field to true
to include all versions for an entire Operator catalog.
Example ImageSetConfiguration
file
apiVersion: mirror.openshift.io/v1alpha2 kind: ImageSetConfiguration storageConfig: registry: imageURL: example.com/mirror/oc-mirror-metadata skipTLS: false mirror: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 full: true
Use case: Including an entire catalog (channel heads only)
The following ImageSetConfiguration
file includes the channel heads for an entire Operator catalog.
By default, for each Operator in the catalog, oc-mirror includes the latest Operator version (channel head) from the default channel. If you want to mirror all Operator versions, and not just the channel heads, you must set the mirror.operators.full
field to true
.
This example also uses the targetCatalog
field to specify an alternative namespace and name to mirror the catalog as.
Example ImageSetConfiguration
file
apiVersion: mirror.openshift.io/v1alpha2 kind: ImageSetConfiguration storageConfig: registry: imageURL: example.com/mirror/oc-mirror-metadata skipTLS: false mirror: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 targetCatalog: my-namespace/my-operator-catalog
Use case: Including arbitrary images and helm charts
The following ImageSetConfiguration
file uses a registry storage backend and includes helm charts and an additional Red Hat Universal Base Image (UBI).
Example ImageSetConfiguration
file
apiVersion: mirror.openshift.io/v1alpha2 kind: ImageSetConfiguration archiveSize: 4 storageConfig: registry: imageURL: example.com/mirror/oc-mirror-metadata skipTLS: false mirror: platform: architectures: - "s390x" channels: - name: stable-4.13 operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.13 helm: repositories: - name: redhat-helm-charts url: https://raw.githubusercontent.com/redhat-developer/redhat-helm-charts/master charts: - name: ibm-mongodb-enterprise-helm version: 0.2.0 additionalImages: - name: registry.redhat.io/ubi9/ubi:latest
Use case: Including the upgrade path for EUS releases
The following ImageSetConfiguration
file includes the eus-<version>
channel, where the maxVersion
value is at least two minor versions higher than the minVersion
value.
For example, in this ImageSetConfiguration
file, the minVersion
is set to 4.12.28
, while the maxVersion
for the eus-4.14
channel is 4.14.16
.
Example ImageSetConfiguration
file
kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v2alpha1 mirror: platform: graph: true # Required for the OSUS Operator architectures: - amd64 channels: - name: stable-4.12 minVersion: '4.12.28' maxVersion: '4.12.28' shortestPath: true type: ocp - name: eus-4.14 minVersion: '4.12.28' maxVersion: '4.14.16' shortestPath: true type: ocp
4.14. Command reference for oc-mirror
The following tables describe the oc mirror
subcommands and flags:
Subcommand | Description |
---|---|
| Generate the autocompletion script for the specified shell. |
| Output the contents of an image set. |
| Show help about any subcommand. |
| Output an initial image set configuration template. |
| List available platform and Operator content and their version. |
| Output the oc-mirror version. |
Flag | Description |
---|---|
| Specify the path to an image set configuration file. |
| If any non image-pull related error occurs, continue and attempt to mirror as much as possible. |
| Disable TLS validation for the target registry. |
| Use plain HTTP for the target registry. |
|
Print actions without mirroring images. Generates |
| Specify the path to an image set archive that was generated by an execution of oc-mirror to load into a target registry. |
| Show the help. |
| Ignore past mirrors when downloading images and packing layers. Disables incremental mirroring and might download more data. |
| Enable mirroring for local OCI catalogs on disk to the target mirror registry. |
|
Generate manifests for |
|
Specify the maximum number of nested paths for destination registries that limit nested paths. The default is |
|
Specify the number of concurrent requests allowed per registry. The default is |
|
Do not push signatures when mirroring local OCI catalogs (with |
|
Provide a registries configuration file to specify an alternative registry location to copy from when mirroring local OCI catalogs (with |
| Skip removal of artifact directories. |
| Do not replace image tags with digest pins in Operator catalogs. |
|
Skip metadata when publishing an image set. This is only recommended when the image set was created with |
| If an image is not found, skip it instead of reporting an error and aborting execution. Does not apply to custom images explicitly specified in the image set configuration. |
| Disable automatic pruning of images from the target mirror registry. |
| Skip digest verification. |
| Disable TLS validation for the source registry. |
| Use plain HTTP for the source registry. |
| Enable mirroring for local OCI catalogs on disk to the target mirror registry.
The |
|
Specify the number for the log level verbosity. Valid values are |