Add AlpineLinux, Add github Action workflow to build images

.github/workflows/README.md

@@ -0,0 +1,26 @@
+# GitHub Actions Workflows
+
+This directory contains GitHub Actions workflows for building Linux images.
+
+## build-linux-images.yml
+
+This workflow builds images for three different Linux distributions:
+- Alpine Linux
+- Arch Linux  
+- Ubuntu 20.04 with kernel 5.15
+
+### Schedule
+- Runs every Monday at 2 AM UTC (weekly)
+- Can also be triggered manually via GitHub UI
+
+### What it does
+1. Checks out the repository
+2. Sets up Packer and QEMU
+3. Builds all three Linux images in sequence
+4. Uploads the resulting qcow2 images as artifacts
+
+### Artifacts
+Each build produces a qcow2 image that is retained for 7 days:
+- `alpine-image`
+- `archlinux-image` 
+- `ubuntu-image`

.github/workflows/build-linux-images.yml

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+name: Build Linux Images
+
+on:
+  schedule:
+    # Run every Monday at 2 AM UTC (weekly)
+    - cron: '0 2 * * 1'
+  workflow_dispatch:
+
+jobs:
+  build-all-images:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Setup Packer
+      uses: hashicorp/setup-packer@v3
+
+    - name: Setup QEMU
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y qemu-system-x86 qemu-utils
+
+    - name: Build Alpine Linux Image
+      run: |
+        cd example_build_alpine
+        packer init .
+        packer build -force alpine.pkr.hcl
+
+    - name: Build Arch Linux Image
+      run: |
+        cd example_build_archlinux
+        packer init .
+        packer build -force archlinux.pkr.hcl
+
+    - name: Build Ubuntu Image
+      run: |
+        cd example_build_ubuntu-20.04-kernel-5.15
+        packer init .
+        packer build -force ubuntu-20.04-kernel-5.15.pkr.hcl
+
+    - name: Upload Alpine Artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: alpine-image
+        path: example_build_alpine/output/*.qcow2
+        retention-days: 7
+
+    - name: Upload Arch Linux Artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: archlinux-image
+        path: example_build_archlinux/output/*.qcow2
+        retention-days: 7
+
+    - name: Upload Ubuntu Artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: ubuntu-image
+        path: example_build_ubuntu-20.04-kernel-5.15/output/*.qcow2
+        retention-days: 7

README.md

@@ -266,3 +266,8 @@ See the [`make_image_bootable.sh`](example_build/files/make_image_bootable.sh) e
 ## Related links
 
 * [Report bugs](https://github.com/ovh/bringyourownlinux/issues)
+
+## Automated Builds
+
+All example images are built automatically on a weekly basis using GitHub Actions.
+See the [.github/workflows](.github/workflows) directory for details.

example_build_alpine/README.md

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+# Alpine Linux Build Example
+
+This directory contains a Packer configuration for building an Alpine Linux image suitable for OVHcloud baremetal servers.
+
+## Files
+
+- `alpine.pkr.hcl` - Main Packer configuration file in HCL format
+- `provision.sh` - Script to prepare the Alpine Linux system for baremetal deployment
+- `make_image_bootable.sh` - Script to make the image bootable on OVHcloud baremetal servers
+
+## Building the Image
+
+To build the image, run:
+
+```bash
+packer build alpine.pkr.hcl
+```
+
+The resulting image will be located in the `output/` directory.
+
+## Configuration Details
+
+This build uses:
+- Alpine Linux v3.20.1 (latest stable release)
+- QEMU builder for virtualization
+- Cloud-init for initial configuration
+- GRUB bootloader configured for baremetal boot
+- Support for RAID, LVM, and various filesystems
+- Intel and AMD microcode support
+
+## Requirements
+
+- Packer 1.7+
+- QEMU/KVM support
+- At least 4GB RAM for building

example_build_alpine/alpine.pkr.hcl

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+packer {
+  required_plugins {
+    qemu = {
+      source  = "github.com/hashicorp/qemu"
+      version = "~> 1"
+    }
+  }
+}
+
+source "qemu" "builder" {
+  # cloud-init will use the CD as datasource, see https://cloudinit.readthedocs.io/en/latest/reference/datasources/nocloud.html#source-2-drive-with-labeled-filesystem
+  cd_label                  = "cidata"
+  cd_content                = {
+    "/meta-data" = ""
+    "/user-data" = <<-EOF
+    #cloud-config
+    ssh_pwauth: true
+    users:
+      - name: packer
+        plain_text_passwd: packer
+        sudo: ALL=(ALL) NOPASSWD:ALL
+        lock_passwd: false
+    EOF
+  }
+  # Enabling this makes the build longer but reduces the image size
+  disk_compression          = true
+  # The source is a disk image, not an ISO file
+  disk_image                = true
+  # Same size as the source image
+  disk_size                 = "2G"
+  format                    = "qcow2"
+  # Do not launch QEMU's GUI
+  headless                  = true
+  iso_checksum              = "file:https://alpinelinux.org/downloads/alpine-v3.20.1-x86_64.iso.sha256"
+  iso_url                   = "https://alpinelinux.org/downloads/alpine-v3.20.1-x86_64.iso"
+  # Allows us to see the VM's console when PACKER_LOG=1 is set
+  qemuargs                  = [["-serial", "stdio"]]
+  # Before shutting down, truncate logs and remove everything linked to the provisioning user
+  shutdown_command          = "sudo sh -c 'find /var/log/ -type f -exec truncate --size 0 {} + && rm -f /etc/sudoers.d/90-cloud-init-users && userdel -fr packer && poweroff'"
+  communicator              = "ssh"
+  ssh_clear_authorized_keys = true
+  ssh_username              = "packer"
+  ssh_password              = "packer"
+  # The resulting image will be written to output/alpine.qcow2
+  output_directory          = "output"
+  vm_name                   = "alpine.qcow2"
+}
+
+build {
+  sources = ["source.qemu.builder"]
+
+  provisioner "shell" {
+    execute_command = "chmod +x {{ .Path }} && sudo {{ .Path }}"
+    script          = "provision.sh"
+  }
+
+  provisioner "file" {
+    destination = "/tmp/make_image_bootable.sh"
+    source      = "make_image_bootable.sh"
+  }
+
+  provisioner "shell" {
+    inline = ["sudo sh -c 'mkdir /root/.ovh/ && mv /tmp/make_image_bootable.sh /root/.ovh/ && chmod -R +x /root/.ovh/'"]
+  }
+}

example_build_alpine/make_image_bootable.sh

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+#!/bin/sh
+
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this
+# file except in compliance with the License. You may obtain a copy of the License at
+# http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software distributed under
+# the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific language
+# governing permissions and limitations under the License.
+
+# This script makes an Alpine Linux image bootable on OVHcloud baremetal servers
+
+set -eo pipefail
+
+configure_console() {
+    echo "Getting console parameters from the cmdline"
+    # Get the right console parameters (including SOL if available) from the
+    # rescue's cmdline - PUBM-16534
+    console_parameters="$(grep -Po '\bconsole=\S+' /proc/cmdline | paste -s -d" ")"
+    if ! grep -qF "$console_parameters" /etc/default/grub; then
+        sed -i "s/GRUB_CMDLINE_LINUX=\"\"/GRUB_CMDLINE_LINUX=\"$console_parameters\"/" /etc/default/grub
+    fi
+
+    # Also pass these parameters to GRUB
+    parameters=$(sed -nE "s/.*\bconsole=ttyS([0-9]),([0-9]+)([noe])([0-9]+)\b.*/\1 \2 \3 \4/p" /proc/cmdline)
+    if [ -z "$parameters" ]; then
+        # No SOL, nothing to do
+        return
+    fi
+    read -r unit speed parity bits <<< "$parameters"
+    declare -A parities=([o]=odd [e]=even [n]=no)
+    parity="${parities["$parity"]}"
+    serial_command="serial --unit=$unit --speed=$speed --parity=$parity --word=$bits"
+
+    if grep -qFx 'GRUB_TERMINAL="console serial"' /etc/default/grub; then
+        # Configuration already applied
+        return
+    fi
+
+    sed -i \
+        -e "/^# Uncomment to disable graphical terminal/d" \
+        -e "s/^#GRUB_TERMINAL=.*/GRUB_TERMINAL=\"console serial\"\nGRUB_SERIAL_COMMAND=\"$serial_command\"/" \
+        /etc/default/grub
+}
+
+# Detect boot mode and install GRUB
+if [ -d /sys/firmware/efi ]; then
+    echo "INFO - GRUB will be configured for UEFI boot"
+    # Pass --no-nvram to avoid changing the boot order, the server needs to boot via PXE
+    grub-install --target=x86_64-efi --no-nvram
+else
+    echo "INFO - GRUB will be configured for legacy boot"
+    bootDevice="$(findmnt -A -c -e -l -n -T /boot/ -o SOURCE)"
+    realBootDevices="$(lsblk -n -p -b -l -o TYPE,NAME $bootDevice -s | awk '$1 == "disk" && !seen[$2]++ {print $2}')"
+    # realBootDevices are disks at this point
+    for realBootDevice in $realBootDevices; do
+        echo "INFO - GRUB will be configured on disk ${realBootDevice}"
+        # realBootDevice is the boot disk device canonical path
+        grub-install --target=i386-pc --force "$realBootDevice"
+    done
+fi
+
+# Configure SOL console
+configure_console
+
+# Generate unique machine-id
+systemd-machine-id-setup
+
+# Generate GRUB config
+grub-mkconfig -o /boot/grub/grub.cfg
+
+# Regenerate initramfs to include e.g. mdadm.conf and required kernel modules
+mkinitfs -b
+
+# Cleanup
+rm -fr /root/.ovh/

example_build_alpine/provision.sh

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+#!/bin/sh
+# This script prepares an Alpine Linux cloud image for OVHcloud baremetal servers
+
+set -euo pipefail
+
+# Update the system
+apk update && apk upgrade
+
+# Install useful packages for baremetal (RAID/LVM/filesystems/microcodes)
+# We need to install packages that support hardware components commonly found in OVH baremetal servers
+apk add --no-cache \
+    mdadm \
+    lvm2 \
+    btrfs-progs \
+    dosfstools \
+    xfsprogs \
+    linux-firmware-intel \
+    intel-ucode \
+    amd-ucode \
+    openrc
+
+# Remove Network configuration
+rm -f /etc/network/interfaces
+
+# Configure GRUB for proper boot on baremetal
+# Alpine uses OpenRC instead of systemd, so we need to adjust accordingly
+# Set default GRUB parameters
+echo 'GRUB_CMDLINE_LINUX_DEFAULT=""' > /etc/default/grub
+echo 'GRUB_CMDLINE_LINUX="nomodeset"' >> /etc/default/grub
+echo 'GRUB_GFXPAYLOAD_LINUX="text"' >> /etc/default/grub
+
+# Add mdadm, LVM and net hooks to the initramfs
+# In Alpine, we need to ensure the right modules are included
+echo 'MODULES="mdraid lvm2"' > /etc/mkinitfs/modules
+echo 'HOOKS="mount rootfs"' > /etc/mkinitfs/hooks
+
+# Remove machine-id, it is regenerated during OS installation
+rm -f /etc/machine-id
+
+# Clean package cache
+apk cache clean