Red Hat build of MicroShift

Embed workload container images for offline use

To embed container images in devices at the edge that do not have any network connection, you must create a new container, mount the ISO, and then copy the contents into the file system.

Prerequisites

You have root access to the host.
Application RPMs have been added to a blueprint.
You installed the OpenShift CLI (oc).

Procedure

Render the manifests, extract all of the container image references, and translate the application image to blueprint container sources by running the following command:
```
$ oc kustomize ~/manifests | grep "image:" | grep -oE '[^ ]+$' | while read line; do echo -e "[[containers]]\nsource = \"${line}\"\n"; done >><my_blueprint>.toml
```
Push the updated blueprint to image builder by running the following command:
```
$ sudo composer-cli blueprints push <my_blueprint>.toml
```
If your workload containers are located in a private repository, you must provide image builder with the necessary pull secrets:
1. Set the auth_file_path in the [containers] section in the /etc/osbuild-worker/osbuild-worker.toml configuration file to point to the pull secret.
2. If needed, create a directory and file for the pull secret, for example:
  Example directory and file
  [containers] auth_file_path = "/<path>/pull-secret.json"
  Use the custom location previously set for copying and retrieving images.

Build the container image by running the following command:

$ sudo composer-cli compose start-ostree <my_blueprint> edge-commit

Proceed with your preferred rpm-ostree image flow, such as waiting for the build to complete, exporting the image and integrating it into your rpm-ostree repository or creating a bootable ISO.