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Chapter 2. Embedding Red Hat build of MicroShift in a RHEL for Edge image

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You can embed Red Hat build of MicroShift into a Red Hat Enterprise Linux (RHEL) for Edge 9.2 image. Use this guide to build a RHEL image containing Red Hat build of MicroShift.

Important

Red Hat build of MicroShift is Technology Preview only. This Technology Preview software is not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using Red Hat build of MicroShift in production. Technology Preview provides early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

Red Hat does not support an update path from the Technology Preview version to later versions of Red Hat build of MicroShift. A new installation is necessary.

For more information about the support scope of Red Hat Technology Preview features, read Technology Preview Features Support Scope.

2.1. Preparing for image building

Read Composing, installing, and managing RHEL for Edge images.

Important

Red Hat build of MicroShift 4.13 deployments have only been tested with Red Hat Enterprise Linux (RHEL) for Edge 9.2. Other versions of RHEL are not supported.

To build an Red Hat Enterprise Linux (RHEL) for Edge 9.2 image for a given CPU architecture, you need a RHEL 9.2 build host of the same CPU architecture that meets the Image Builder system requirements.

Follow the instructions in Installing Image Builder to install Image Builder and the composer-cli tool.

2.2. Adding Red Hat build of MicroShift repositories to Image Builder

Use the following procedure to add the Red Hat build of MicroShift repositories to Image Builder on your build host.

Prerequisites

  • Your build host meets the Image Builder system requirements.
  • You have installed and set up Image Builder and the composer-cli tool.
  • You have root-user access to your build host.

Procedure

  1. Create an Image Builder configuration file for adding the rhocp-4.13 RPM repository source required to pull Red Hat build of MicroShift RPMs by running the following command:

    $ cat > rhocp-4.13.toml <<EOF
    id = "rhocp-4.13"
    name = "Red Hat OpenShift Container Platform 4.13 for RHEL 9"
    type = "yum-baseurl"
    url = "https://cdn.redhat.com/content/dist/layered/rhel9/$(uname -m)/rhocp/4.13/os"
    check_gpg = true
    check_ssl = true
    system = false
    rhsm = true
    EOF
  2. Create an Image Builder configuration file for adding the fast-datapath RPM repository by running the following command:

    $ cat > fast-datapath.toml <<EOF
    id = "fast-datapath"
    name = "Fast Datapath for RHEL 9"
    type = "yum-baseurl"
    url = "https://cdn.redhat.com/content/dist/layered/rhel9/$(uname -m)/fast-datapath/os"
    check_gpg = true
    check_ssl = true
    system = false
    rhsm = true
    EOF
  3. Add the sources to the Image Builder by running the following commands:

    $ sudo composer-cli sources add rhocp-4.13.toml
    $ sudo composer-cli sources add fast-datapath.toml

Verification

  • Confirm that the sources were added properly by running the following command:

    $ sudo composer-cli sources list

    Example output

    appstream
    baseos
    fast-datapath
    rhocp-4.13

2.3. Adding the Red Hat build of MicroShift service to a blueprint

Adding the Red Hat build of MicroShift RPM package to an Image Builder blueprint enables the build of a RHEL for Edge image with Red Hat build of MicroShift embedded.

Procedure

  1. Use the following example to create your blueprint:

    Image Builder blueprint example

    $ cat > minimal-microshift.toml <<EOF
    name = "minimal-microshift"
    
    description = ""
    version = "0.0.1"
    modules = []
    groups = []
    
    [[packages]]
    name = "microshift"
    version = "*"
    
    [[packages]]
    name = "microshift-greenboot" 1
    version = "*"
    
    [customizations.services]
    enabled = ["microshift"]
    EOF

    1
    Optional microshift-greenboot RPM. For more information, read the "Greenboot health check" guide in the "Running Applications" section.
    Note

    The wildcard * in the commands uses the latest Red Hat build of MicroShift RPMs. If you need a specific version, substitute the wildcard for the version you want. For example, insert 4.13.1 to download the Red Hat build of MicroShift 4.13.1 RPMs.

  2. Add the blueprint to the Image Builder by running the following command:

    $ sudo composer-cli blueprints push minimal-microshift.toml

Verification

  1. Verify the Image Builder configuration listing only Red Hat build of MicroShift packages by running the following command:

    $ sudo composer-cli blueprints depsolve minimal-microshift | grep microshift

    Example output

    blueprint: minimal-microshift v0.0.1
        microshift-greenboot-4.13.1-202305250827.p0.g4105d3b.assembly.4.13.1.el9.noarch
        microshift-networking-4.13.1-202305250827.p0.g4105d3b.assembly.4.13.1.el9.x86_64
        microshift-release-info-4.13.1-202305250827.p0.g4105d3b.assembly.4.13.1.el9.noarch
        microshift-4.13.1-202305250827.p0.g4105d3b.assembly.4.13.1.el9.x86_64
        microshift-selinux-4.13.1-202305250827.p0.g4105d3b.assembly.4.13.1.el9.noarch

  2. Optional: Verify the Image Builder configuration listing all components to be installed by running the following command:

    $ sudo composer-cli blueprints depsolve minimal-microshift

2.4. Creating the Red Hat Enterprise Linux (RHEL) for Edge image

Use the following procedure to create the ISO. The RHEL for Edge Installer image pulls the commit from the running container and creates an installable boot ISO with a Kickstart file configured to use the embedded OSTree commit.

Prerequisites

  • Your build host meets the Image Builder system requirements.
  • You have installed and set up Image Builder and the composer-cli tool.
  • You have root-user access to your build host.
  • You have the podman tool.

Procedure

  1. Start an ostree container image build by running the following command:

    $ BUILDID=$(sudo composer-cli compose start-ostree --ref "rhel/9/$(uname -m)/edge" minimal-microshift edge-container | awk '{print $2}')

    This command also returns the identification (ID) of the build for monitoring.

  2. You can check the status of the build periodically by running the following command:

    $ sudo composer-cli compose status

    Example output of a running build

    ID                                     Status     Time                      Blueprint            Version   Type               Size
    cc3377ec-4643-4483-b0e7-6b0ad0ae6332   RUNNING    Wed Jun 7 12:26:23 2023   minimal-microshift   0.0.1     edge-container

    Example output of a completed build

    ID                                     Status     Time                      Blueprint            Version   Type               Size
    cc3377ec-4643-4483-b0e7-6b0ad0ae6332   FINISHED   Wed Jun 7 12:32:37 2023   minimal-microshift   0.0.1     edge-container

    Note

    You can use the watch command to monitor your build if you are familiar with how to start and stop it.

  3. Download the container image using the ID and get the image ready for use by running the following command:

    $ sudo composer-cli compose image ${BUILDID}
  4. Change the ownership of the downloaded container image to the current user by running the following command:

    $ sudo chown $(whoami). ${BUILDID}-container.tar
  5. Add read permissions for the current user to the image by running the following command:

    $ sudo chmod a+r ${BUILDID}-container.tar
  6. Bootstrap a server on port 8085 for the ostree container image to be consumed by the ISO build by completing the following steps:

    1. Get the IMAGEID variable result by running the following command:

      $ IMAGEID=$(cat < "./${BUILDID}-container.tar" | sudo podman load | grep -o -P '(?<=sha256[@:])[a-z0-9]*')
    2. Use the IMAGEID variable result to execute the podman command step by running the following command:

      $ sudo podman run -d --name=minimal-microshift-server -p 8085:8080 ${IMAGEID}

      This command also returns the ID of the container saved in the IMAGEID variable for monitoring.

  7. Generate the installer blueprint file by running the following command:

    $ cat > microshift-installer.toml <<EOF
    name = "microshift-installer"
    
    description = ""
    version = "0.0.0"
    modules = []
    groups = []
    packages = []
    EOF

2.5. Add the blueprint to Image Builder and build the ISO

  1. Add the blueprint to the Image Builder by running the following command:

    $ sudo composer-cli blueprints push microshift-installer.toml
  2. Start the ostree ISO build by running the following command:

    $ BUILDID=$(sudo composer-cli compose start-ostree --url http://localhost:8085/repo/ --ref "rhel/9/$(uname -m)/edge" microshift-installer edge-installer | awk '{print $2}')

    This command also returns the identification (ID) of the build for monitoring.

  3. You can check the status of the build periodically by running the following command:

    $ sudo composer-cli compose status

    Example output for a running build

    ID                                     Status     Time                      Blueprint              Version   Type               Size
    c793c24f-ca2c-4c79-b5b7-ba36f5078e8d   RUNNING    Wed Jun 7 13:22:20 2023   microshift-installer   0.0.0     edge-installer

    Example output for a completed build

    ID                                     Status     Time                      Blueprint              Version   Type               Size
    c793c24f-ca2c-4c79-b5b7-ba36f5078e8d   FINISHED   Wed Jun 7 13:34:49 2023   microshift-installer   0.0.0     edge-installer

2.6. Download the ISO and prepare it for use

  1. Download the ISO using the ID by running the following command:

    $ sudo composer-cli compose image ${BUILDID}
  2. Change the ownership of the downloaded container image to the current user by running the following command:

    $ sudo chown $(whoami). ${BUILDID}-installer.iso
  3. Add read permissions for the current user to the image by running the following command:

    $ sudo chmod a+r ${BUILDID}-installer.iso

2.7. Provisioning a machine for Red Hat build of MicroShift

Provision a machine with your RHEL for Edge image by using the procedures from the RHEL for Edge documentation.

To use Red Hat build of MicroShift, you must provision the system so that it meets the following requirements:

  • The machine you are provisioning must meet the system requirements for installing Red Hat build of MicroShift.
  • The file system must have a logical volume manager (LVM) volume group (VG) with sufficient capacity for the persistent volumes (PVs) of your workload.
  • A pull secret from the Red Hat Hybrid Cloud Console must be present as /etc/crio/openshift-pull-secret and have root user-only read/write permissions.
  • The firewall must be configured with Red Hat build of MicroShift’s required firewall settings.
Note

If you are using a Kickstart such as the RHEL for Edge Installer (ISO) image, you can update your Kickstart file to meet the provisioning requirements.

Prerequisites

  1. You have created an RHEL for Edge Installer (ISO) image containing your RHEL for Edge commit with Red Hat build of MicroShift.

    1. This requirement includes the steps of composing an RFE Container image, creating the RFE Installer blueprint, starting the RFE container, and composing the RFE Installer image.
  2. Create a Kickstart file or use an existing one. In the Kickstart file, you must include:

    1. Detailed instructions about how to create a user.
    2. How to fetch and deploy the RHEL for Edge image.

For more information, read "Additional resources."

Procedure

  1. In the main section of the Kickstart file, update the setup of the filesystem such that it contains an LVM volume group called rhel with at least 10GB system root. Leave free space for the LVMS CSI driver to use for storing the data for your workloads.

    Example kickstart snippet for configuring the filesystem

    # Partition disk such that it contains an LVM volume group called `rhel` with a
    # 10GB+ system root but leaving free space for the LVMS CSI driver for storing data.
    #
    # For example, a 20GB disk would be partitioned in the following way:
    #
    # NAME          MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
    # sda             8:0    0  20G  0 disk
    # ├─sda1          8:1    0 200M  0 part /boot/efi
    # ├─sda1          8:1    0 800M  0 part /boot
    # └─sda2          8:2    0  19G  0 part
    #  └─rhel-root  253:0    0  10G  0 lvm  /sysroot
    #
    ostreesetup --nogpg --osname=rhel --remote=edge \
    --url=file:///run/install/repo/ostree/repo --ref=rhel/<RHEL VERSION NUMBER>/x86_64/edge
    zerombr
    clearpart --all --initlabel
    part /boot/efi --fstype=efi --size=200
    part /boot --fstype=xfs --asprimary --size=800
    # Uncomment this line to add a SWAP partition of the recommended size
    #part swap --fstype=swap --recommended
    part pv.01 --grow
    volgroup rhel pv.01
    logvol / --vgname=rhel --fstype=xfs --size=10000 --name=root
    # To add users, use a line such as the following
    user --name=<YOUR_USER_NAME> \
    --password=<YOUR_HASHED_PASSWORD> \
    --iscrypted --groups=<YOUR_USER_GROUPS>

  2. In the %post section of the Kickstart file, add your pull secret and the mandatory firewall rules.

    Example Kickstart snippet for adding the pull secret and firewall rules

    %post --log=/var/log/anaconda/post-install.log --erroronfail
    
    # Add the pull secret to CRI-O and set root user-only read/write permissions
    cat > /etc/crio/openshift-pull-secret << EOF
    YOUR_OPENSHIFT_PULL_SECRET_HERE
    EOF
    chmod 600 /etc/crio/openshift-pull-secret
    
    # Configure the firewall with the mandatory rules for MicroShift
    firewall-offline-cmd --zone=trusted --add-source=10.42.0.0/16
    firewall-offline-cmd --zone=trusted --add-source=169.254.169.1
    
    %end

  3. Install the mkksiso tool by running the following command:

    $ sudo yum install -y lorax
  4. Update the Kickstart file in the ISO with your new Kickstart file by running the following command:

    $ sudo mkksiso <your_kickstart>.ks <your_installer>.iso <updated_installer>.iso

2.8. How to access the Red Hat build of MicroShift cluster

Use the procedures in this section to access the Red Hat build of MicroShift cluster, either from the same machine running the Red Hat build of MicroShift service or remotely from a workstation. You can use this access to observe and administrate workloads. When using these steps, choose the kubeconfig file that contains the host name or IP address you want to connect with and place it in the relevant directory. As listed in each procedure, you use the OpenShift Container Platform CLI tool (oc) for cluster activities.

2.8.1. Accessing the Red Hat build of MicroShift cluster locally

Use the following procedure to access the Red Hat build of MicroShift cluster locally by using a kubeconfig file.

Prerequisites

  • You have installed the oc binary.

Procedure

  1. Optional: to create a ~/.kube/ folder if your RHEL machine does not have one, run the following command:

    $ mkdir -p ~/.kube/
  2. Copy the generated local access kubeconfig file to the ~/.kube/ directory by running the following command:

    $ sudo cat /var/lib/microshift/resources/kubeadmin/kubeconfig > ~/.kube/config
  3. Update the permissions on your ~/.kube/config file by running the following command:

    $ chmod go-r ~/.kube/config

Verification

  • Verify that Red Hat build of MicroShift is running by entering the following command:

    $ oc get all -A

2.8.2. Opening the firewall for remote access to the Red Hat build of MicroShift cluster

Use the following procedure to open the firewall so that a remote user can access the Red Hat build of MicroShift cluster. This procedure must be completed before a workstation user can access the cluster remotely.

For this procedure, user@microshift is the user on the Red Hat build of MicroShift host machine and is responsible for setting up that machine so that it can be accessed by a remote user on a separate workstation.

Prerequisites

  • You have installed the oc binary.
  • Your account has cluster administration privileges.

Procedure

  • As user@microshift on the Red Hat build of MicroShift host, open the firewall port for the Kubernetes API server (6443/tcp) by running the following command:

    [user@microshift]$ sudo firewall-cmd --permanent --zone=public --add-port=6443/tcp && sudo firewall-cmd --reload

Verification

  • As user@microshift, verify that Red Hat build of MicroShift is running by entering the following command:

    [user@microshift]$ oc get all -A

2.8.3. Accessing the Red Hat build of MicroShift cluster remotely

Use the following procedure to access the Red Hat build of MicroShift cluster from a remote workstation by using a kubeconfig file.

The user@workstation login is used to access the host machine remotely. The <user> value in the procedure is the name of the user that user@workstation logs in with to the Red Hat build of MicroShift host.

Prerequisites

  • You have installed the oc binary.
  • The @user@microshift has opened the firewall from the local host.

Procedure

  1. As user@workstation, create a ~/.kube/ folder if your RHEL machine does not have one by running the following command:

    [user@workstation]$ mkdir -p ~/.kube/
  2. As user@workstation, set a variable for the hostname of your Red Hat build of MicroShift host by running the following command:

    [user@workstation]$ MICROSHIFT_MACHINE=<name or IP address of Red Hat build of MicroShift machine>
  3. As user@workstation, copy the generated kubeconfig file that contains the host name or IP address you want to connect with from the RHEL machine running Red Hat build of MicroShift to your local machine by running the following command:

    [user@workstation]$ ssh <user>@$MICROSHIFT_MACHINE "sudo cat /var/lib/microshift/resources/kubeadmin/$MICROSHIFT_MACHINE/kubeconfig" > ~/.kube/config
  4. As user@workstation, update the permissions on your ~/.kube/config file by running the following command:

    $ chmod go-r ~/.kube/config

Verification

  • As user@workstation, verify that Red Hat build of MicroShift is running by entering the following command:

    [user@workstation]$ oc get all -A
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