Merge pull request #63 from jmarrero/iniramfs

initramfs-module: add example adding a module to the initramfs

.github/workflows/initramfs-module.yml

@@ -0,0 +1,34 @@
+name: "Build image: initramfs-module"
+
+env:
+  IMAGE_NAME: "initramfs-module"
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - initramfs-module/*
+      - .github/workflows/initramfs-module.yml
+  push:
+    branches:
+      - main
+    paths:
+      - initramfs-module/*
+      - .github/workflows/initramfs-module.yml
+
+jobs:
+  build-image:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v3
+
+      - name: Build container image
+        uses: redhat-actions/buildah-build@v2
+        with:
+          context: ${{ env.IMAGE_NAME }}
+          containerfiles: ${{ env.IMAGE_NAME }}/Containerfile
+          image: ${{ env.IMAGE_NAME }}
+          layers: false
+          oci: true

README.md

@@ -18,6 +18,7 @@ functionality.
 - [ansible-firewalld](ansible-firewalld/): Demos using [Ansible](https://github.com/ansible/ansible) to configure [firewalld](https://github.com/firewalld/firewalld)
 - [build-zfs-module](build-zfs-module/): Build the ZFS third party module as rpm and install it
 - [butane](butane/): Demos using https://github.com/coreos/butane
+- [initramfs-module](initramfs-module/): Demos generating a initramfs with specific modules added and omitted.
 - [inject-go-binary](inject-go-binary/): Demos adding building and injecting a Go binary + systemd unit
 - [podman-next](podman-next): Use COPR to install the podman-next package
 - [rsyslog](rsyslog/): Install and configure rsyslog to forward to a remote host

initramfs-module/Containerfile

@@ -0,0 +1,17 @@
+# This examples rebuilds the initramfs adding ostree, iscsi, ifcfg modules
+# omiting the network-legacy and nouveau modules. After the initramfs is built it is moved to
+# /lib/modules/$KERNEL_VERSION/initramfs.img where it will be used on ostree systems.
+FROM quay.io/fedora/fedora-coreos:stable
+USER root
+RUN KERNEL_VERSION=$(rpm -q kernel | cut -c 8-); \
+    # In FCOS we add configuration files for dracut to ensure that the "base image" has its 
+    # initramfs arguments embedded. They can be seen on:
+    # https://github.com/coreos/fedora-coreos-config/tree/testing-devel/overlay.d/05core/usr/lib/dracut
+    # This makes sure that required arguments are reused when running dracut in a container build like this one.
+    # Other distributions like RHCOS might not provide/require the same arguments and will need to be added to the
+    # dracut invocation.
+    # The RCHOS arguments needed can be seen on:
+    # https://github.com/openshift/os/blob/1f2c0eb7e370d2412db15fa28556f419ddf73c5d/common.yaml#L37
+    dracut --reproducible -v --add 'ostree' -f --omit-drivers 'nouveau' \
+    --add 'iscsi' --add 'ifcfg' --omit 'network-legacy' /lib/modules/$KERNEL_VERSION/initramfs.img $KERNEL_VERSION && \
+    ostree container commit