tonyjames/demo-rfe

RHEL for Edge Demo

This presents a demonstration of RHEL for Edge that includes:

• atomic upgrade of the underlying operating system
• greenboot to control whether the atomic upgrade succeeds
• hosting container workloads that can be independently updated

Setup

Start with a minimal install of RHEL 8.3+. Make sure this repository is on the host using either git or scp this directly. Make sure the demo.conf script has your Red Hat Subscription Manager (RHSM) credentials to login to the customer support portal and pull updated content. Also, make sure the IP addresses in the demo.conf file match both your build server and your intended edge host. Use the following scripts to build the needed environment.

cd ~/demo-rfe
sudo ./01-setup-rhel8.sh
reboot
sudo ./02-config-image-builder.sh
sudo ./03-config-registry.sh
./04-build-containers.sh

The above scripts do the following:

• subscribe to Red Hat for updates
• enable virtualization
• install and enable the web console and image builder
• enable a local insecure registry on the host
• build two versions of a container app and push both to the local registry

Compose the os-tree images

Next, use the composer-cli tool to create the initial os-tree repository. Inspect the provided blueprint file which defines a default user and enables port 8080 in the firewall.

cat RFE.toml

Next, push the blueprint file to the image builder server:

composer-cli blueprints push RFE.toml

Launch an image build:

composer-cli compose start RFE rhel-edge-commit

The image will take between five and ten minutes to build. You can check the status using:

composer-cli compose status

When the image has a status of FINISHED, create a directory to hold the expanded content as well as the needed kickstart file. Use command completion by just pressing the TAB key to make the appropriate IMAGE_UUID appear in the below composer-cli command.

mkdir -p ~/0.0.1
cd ~/0.0.1
composer-cli compose image IMAGE_UUID

Link the edge.ks file to the new directory and extract the tar file for the image.

ln -s ../demo-rfe/edge.ks .
tar xf  *.tar

After the content is expanded, the directory will have a compose.json file in addition to the ostree repository. Review the JSON file and copy the ostree-commit value to the clipboard. You'll use that when creating an image derived from this one in the web console.

jq '.' compose.json

The list of rpm packages included in the commit can be listed via:

rpm-ostree db list rhel/8/x86_64/edge --repo=repo

Create the second image using the web console. Browse to https://YOUR-HOST-NAME:9090 and log in as a user with admin privileges (or at least a member of the weldr group). Once you're logged in, select "Image Builder" in the navigation bar in the left hand side.

Click the link to the right of the RFE blueprint labeled Edit Packages. Under "Available Components", type strace in the box with text "Filter By Name..." and then press ENTER.

Click the "+" to the right of the strace package to add it to the blueprint components on the right hand side. Select the "Commit" button to update the version number and commit this change to the blueprint.

You'll be asked to confirm the commit so just select "Commit" again. Next, select "Create Image" to kickoff a build of the image. In the dialog, select RHEL for Edge Commit (.tar) for the Type field and paste the ostree-commit value you copied into the clipboard into the Parent commit field. Select the "Create" button to kick off the image build.

The build will take between five and ten minutes to complete. Once it's finished, list the image UUIDs on the command line using:

composer-cli compose status

The output will look something like this:

149b153b-82a8-4adb-8f36-27481ac2d0f2 FINISHED Mon Dec  7 14:17:32 2020 RFE
       0.0.1 rhel-edge-commit
12a775e4-1300-428f-a62c-505042948616 FINISHED Mon Dec  7 14:54:19 2020 RFE
       0.0.2 rhel-edge-commit 2147483648

We want to work with the UUID matching the 0.0.2 version of the image build. For the composer-cli compose image command below, use command completion by just pressing the TAB key and selecting the UUID matching version 0.0.2 as shown above.

mkdir -p ~/0.0.2
cd ~/0.0.2
composer-cli compose image IMAGE_UUID

Link the edge.ks file to the new directory and extract the tar file for the image.

ln -s ../demo-rfe/edge.ks .
tar xf  *.tar

The list of rpm packages included in the commit can be listed via:

rpm-ostree db list rhel/8/x86_64/edge --repo=repo

Demo

You're now ready to demonstrate this capability. On the server where you've built the images, go to the 0.0.1 folder which holds the initial build and run a simple web server to offer that content to clients:

cd ~/0.0.1
ln -s ../demo-rfe/main.go .
go run main.go

Download the RHEL 8.3 Boot ISO and place it in the same directory as this repository.

Launch a separate terminal and then create a guest VM using the rhel-8.3-x86_64-boot.iso file.

cd ~/demo-rfe
./05-launch-edge-guest.sh

and then press tab at the installation screen to customize the installation. Append the following to the end of the command line:

inst.ks=http://BUILD-HOST-IP:8000/edge.ks ip.method=dhcp

where BUILD-HOST-IP matches the address of your build server with the ostree content.