Add dracut-module example

- [x] Add dracut-module example Containerfile and readme
- [x] Add dracut-module example to main readme
- [x] Add dracut-module github workflow file
- [x] Test build dracut-module example

.github/workflows/dracut-module.yml

@@ -0,0 +1,34 @@
+name: "Build image: dracut-module"
+
+env:
+  IMAGE_NAME: "dracut-module"
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - dracut-module/*
+      - .github/workflows/dracut-module.yml
+  push:
+    branches:
+      - main
+    paths:
+      - dracut-module/*
+      - .github/workflows/dracut-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

@@ -19,6 +19,7 @@ functionality.
 - [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
 - [convert-ubuntu-package](convert-ubuntu-package/): Convert an Ubuntu package to rpm using [alien](https://wiki.debian.org/Alien) and install it.
+- [dracut-module](dracut-module): Install and run a dracut module
 - [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

convert-ubuntu-package/README.md

@@ -1,5 +1,5 @@
 # Convert an Ubuntu Package and Install It
 
-This example converts an Ubuntu package into an rpm using [alien](https://wiki.debian.org/Alien) an then installs it using `rpm-ostree`.
+This example converts an Ubuntu package into an rpm using [alien](https://wiki.debian.org/Alien) and then installs it using `rpm-ostree`.
 
 This is useful for packages that are present in Ubuntu, but not in Fedora. This example installs Ubuntu's latest packaged version of gocryptfs, which is [no longer maintained in Fedora](https://discussion.fedoraproject.org/t/gocryptfs-not-available-on-fedora-36).

dracut-module/Containerfile

@@ -0,0 +1,25 @@
+# Install and run a dracut module
+FROM quay.io/fedora/fedora-coreos:stable
+
+# Install dracut module requirements
+RUN rpm-ostree install busybox rng-tools pcsc-tools bluez && \
+    ostree container commit
+
+# Add dracut module files
+COPY files/ /usr/lib/dracut/modules.d/10systemd-echo-here/
+
+# Run dracut to build a new initrd
+RUN stock_arguments=$(lsinitrd /lib/modules/6.4.7-200.fc38.x86_64/initramfs.img  | grep '^Arguments: ' | sed 's/^Arguments: //') && \
+    mkdir -p /tmp/dracut /var/roothome && \
+    bash <(/usr/bin/echo "dracut $stock_arguments") && \
+    rm -rf /var/* /tmp/*  && \
+    ostree container commit
+
+# Move the new initrd into place while keeping the stock initrd in the image for reference.
+RUN export KERNEL_VERSION="$(rpm -qa kernel --queryformat '%{VERSION}-%{RELEASE}.%{ARCH}')" && \
+    mv -v "/lib/modules/${KERNEL_VERSION}/initramfs.img" "/lib/modules/${KERNEL_VERSION}/initramfs.stock.img" && \
+    mv -v /boot/initramfs*.img "/lib/modules/${KERNEL_VERSION}/initramfs.img" && \
+    ostree container commit
+
+# Show that the initrd includes the echo-here service:
+RUN lsinitrd /lib/modules/*/initramfs.img | grep echo-here

dracut-module/README.md

@@ -0,0 +1,7 @@
+# Install and run a dracut module
+
+This example adds a dracut module to the container and calls dracut to build a new initrd using this module.
+
+This is useful when something needs to run inside of the initrd, which is very early in the boot process.
+
+This specific example registers a systemd service that prints out when it was executed.

dracut-module/files/echo-here.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Service to Echo Here During initrd Startup
+DefaultDependencies=no
+ConditionVirtualization=!container
+
+Requires=systemd-udev-settle.service
+After=systemd-udev-settle.service
+Before=cryptsetup.target
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/echo --------------------HERE--------------------
+

dracut-module/files/module-setup.sh

@@ -0,0 +1,9 @@
+depends() {
+    echo systemd
+    return 0
+}
+
+install() {                                                                     
+    inst_simple "${moddir}/echo-here.service" "${systemdsystemunitdir}/echo-here.service"
+    $SYSTEMCTL -q --root "$initdir" add-wants cryptsetup.target echo-here.service
+}