Chapter 4. Embedding MicroShift applications tutorial

1. To embed MicroShift on RHEL for Edge, you added the MicroShift repositories to Image Builder.
2. You created a blueprint that declared all the RPMs, container images, files and customizations you needed, including the addition of MicroShift.
3. You added the blueprint to Image Builder and ran a build with the Image Builder CLI tool (composer-cli). This step created rpm-ostree commits, which were used to create the container image. This image contained RHEL for Edge.
4. You added the installer blueprint to Image Builder to create an rpm-ostree image (ISO) to boot from. This build contained both RHEL for Edge and MicroShift.
5. You downloaded the ISO with MicroShift embedded, prepared it for use, provisioned it, then installed it onto your edge devices.

Procedure

1. Install the rpmbuild tool and create the yum repository for it by running the following command:

   $ sudo dnf install rpmdevtools rpmlint yum-utils createrepo

2. Create the file tree you need to build RPM packages by running the following command:

   $ rpmdev-setuptree

Procedure

1. In the ~/rpmbuild/SPECS directory, create a file such as <application_workload_manifests.spec> using the following template:

   Example spec file

   Name: <application_workload_manifests>
   Version: 0.0.1
   Release: 1%{?dist}
   Summary: Adds workload manifests to microshift
   BuildArch: noarch
   License: GPL
   Source0: %{name}-%{version}.tar.gz
   #Requires: microshift
   %description
   Adds workload manifests to microshift
   %prep
   %autosetup
   %install 1
   rm -rf $RPM_BUILD_ROOT
   mkdir -p $RPM_BUILD_ROOT/%{_prefix}/lib/microshift/manifests
   cp -pr ~/manifests $RPM_BUILD_ROOT/%{_prefix}/lib/microshift/
   %clean
   rm -rf $RPM_BUILD_ROOT
   
   %files
   %{_prefix}/lib/microshift/manifests/**
   %changelog
   * <DDD MM DD YYYY username@domain - V major.minor.patch>
   - <your_change_log_comment>

   1

   The %install section creates the target directory inside the RPM package, /usr/lib/microshift/manifests/ and copies the manifests from the source home directory, ~/manifests.

   Important

   All of the required YAML files must be in the source home directory ~/manifests, including a kustomize.yaml file if you are using kustomize.

2. Build your RPM package in the ~/rpmbuild/RPMS directory by running the following command:

   $ rpmbuild -bb ~/rpmbuild/SPECS/<application_workload_manifests.spec>

Procedure

1. Create a local RPM repository by running the following command:

   $ createrepo ~/rpmbuild/RPMS/

2. Give Image Builder access to the RPM repository by running the following command:

   $ sudo chmod a+rx ~

   Note

   You must ensure that Image Builder has all of the necessary permissions to access all of the files needed for image building, or the build cannot proceed.

3. Create the blueprint file, repo-local-rpmbuild.toml using the following template:

   id = "local-rpm-build"
   name = "RPMs build locally"
   type = "yum-baseurl"
   url = "file://<path>/rpmbuild/RPMS" 1
   check_gpg = false
   check_ssl = false
   system = false

   1

   Specify part of the path to create a location that you choose. Use this path in the later commands to set up the repository and copy the RPMs.

4. Add the repository as a source for Image Builder by running the following command:

   $ sudo composer-cli sources add repo-local-rpmbuild.toml

5. Add the RPM to your blueprint, by adding the following lines:

   …
   [[packages]]
   name = "<application_workload_manifests>" 1
   version = "*"
   …

   1

   Add the name of your workload here.

6. Push the updated blueprint to Image Builder by running the following command:

   $ sudo composer-cli blueprints push repo-local-rpmbuild.toml

7. At this point, you can either run Image Builder to create the ISO, or embed the container images for offline use.

   1. To create the ISO, start Image Builder by running the following command:

      $ sudo composer-cli compose start-ostree repo-local-rpmbuild edge-commit