[Guide + Question] Using livemedia-creator to create an ISO in Github Actions

[Cameronsplaze]

I think I finally have a custom Fedora ISO built from inside Github Actions! There's a couple areas I have questions on. (Fyi it takes ~40-50min)

My command to create the image so far is:

livemedia-creator --ks Fedora-custom-ks.cfg --no-virt --make-iso --iso-only --iso-name Fedora-custom-39-KDE.iso --project Fedora-custom--volid Fedora-custom-39 --releasever 39

Contents of Fedora-custom-ks.cfg so far

# Keyboard layouts
keyboard 'us'
# Root password
rootpw --iscrypted --lock locked
# System language
lang en_US.UTF-8
# System timezone
timezone US/Eastern
# Network information
network  --bootproto=dhcp --device=link --activate
# Firewall configuration
firewall --enabled # --service=mdns
# Use network installation
url --mirrorlist="https://mirrors.fedoraproject.org/mirrorlist?repo=fedora-$releasever&arch=$basearch"

## System services (UNCOMMENT for example of error)
# services --disabled="sshd,custom-device-pollrates" --enabled="NetworkManager,ModemManager,supergfxd,akmods"

# System bootloader configuration
bootloader --location=none

# Clear the Master Boot Record
zerombr
# Partition clearing information
clearpart --all
# Disk partitioning information
# autopart
part / --size=6144 --fstype="ext4" --grow --asprimary --recommended
part swap --recommended # Is this line not needed for --iso-only?

# Shutdown after installation
shutdown

# Packages to be installed
%packages
# Required for livemedia-creator:
dracut-live
@^kde-desktop-environment
# Everything else:
@virtualization
@anaconda-tools
%end

# pre-installation commands
%pre --erroronfail
# Add pre-installation commands here
%end

# Post-installation commands
%post --erroronfail
# Add post-installation commands here
%end

A working GH action, in case anyone is looking to do the same

name: Build Fedora ISO

on:
  workflow_dispatch: {}

jobs:

  fedora-build:
    runs-on: ubuntu-latest
    container:
      image: fedora:latest
      # --privileged needed for livemedia-creator
      options: --privileged
    steps:
      - uses: actions/checkout@v4

      - name: Install dependencies
        run: |
          # zstd: Lets you use github caching actions inside fedora too
          # lorax lorax-lmc-novirt anaconda pykickstart: To actually build the ISO
          dnf install -y zstd lorax lorax-lmc-novirt anaconda pykickstart

      ## Create the ISO
      - name: Create the custom ISO
        run: |
          cd ./OS-Builder
          livemedia-creator \
            --ks CustomFedora-ks.cfg \
            --no-virt \
            --make-iso \
            --iso-only \
            --iso-name CustomFedora-39-KDE.iso \
            --project CustomFedora \
            --volid CustomFedora-39 \
            --releasever 39 \
            --resultdir ./Results

      - name: Upload ISO
        uses: actions/upload-artifact@v3
        with:
          name: CustomFedora-39-KDE.iso
          path: ./OS-Builder/Results/CustomFedora-39-KDE.iso

      ## Capture debug info if it fails, and logs exist:
      - name: "DEBUG: Print virt-install log"
        if: failure() && hashFiles('./OS-Builder/virt-install.log') != ''
        run: cat ./OS-Builder/virt-install.log

      - name: "DEBUG: Print livemedia log"
        if: failure() && hashFiles('./OS-Builder/livemedia.log') != ''
        run: cat ./OS-Builder/livemedia.log

My main goal is to have a custom ISO with extra packages installed, and (eventually) a custom Desktop Environment added to the iso. I still want users to "install" the iso to their system with setting up partitions themselves, along with the root and user accounts, etc.

---

It seems like with livemedia-creator --make-iso --iso-only --no-virt ..., the part / argument is still required. I can't use autopart either to just ignore it. I want this part to be exactly like the Fedora install setup, where users customize it themselves. Maybe I don't understand what this param does? Or is livemedia-creator not the right tool for what I'm trying to do?

• If part / is setting up the partitions to use after the install, I want this to be completely on the user. Like fedora currently, where you have to select what drives to wipe, then click a button to add a sensible /boot, /, swap, etc. But you still can override and customize that area. Does this just declare what "sensible" is maybe? With --iso-only, I'm hoping users can still customize the install process.
• If this argument is just how to configure the VM when creating it with QEMU, I have --no-virt passed, so it should be doing everything inside the container. No vm needed?
• If it's the size of the ISO, is there a way to make it minimal? I had a size error with --size=1 --grow. Can I just have a placeholder one like above, and ignore this key otherwise?

---

Also I've noticed the longest step is easily when it says Creating a squashfs+ext4 runtime towards the end of the output to the console. Is there anything I could potentially do to speed this up? I'm going to look at adding caching to the dnf install step too, is there another directory I could try to cache too maybe?

[bcl]

The part / is needed because it has to make a disk image to install everything onto. It only effects the iso / filesystem not the final install, that's all handled by anaconda being run after booting the iso. The size of / doesn't actually matter too much, it gets compressed so making it large has a minimal size penalty on the final image. To make things a bit smaller you can use the new --squashfs-only argument and it skips the ext4 wrapped in squashfs step and just makes a squashfs filesystem. It should be slightly faster than the squashfs+ext4 method.

[Cameronsplaze]

Thanks! I simplified the part / section, and the --squashfs-only flag saved ~5 minutes too.

Would you like a PR to add an example livemedia-creator GH action to this repo? I could try pointing it at https://github.com/weldr/lorax/blob/master/docs/fedora-minimized.ks since it's already there, and it uses url= so --no-virt should work. With the trigger as a workflow_dispatch, the action will only run when you want it to. I also added a ksvalidator step to help it error faster if something's wrong.

[bcl]

Thanks! I simplified the part / section, and the --squashfs-only flag saved ~5 minutes too.

Nice!

Would you like a PR to add an example livemedia-creator GH action to this repo?

Sure, PR's always welcome!

[Cameronsplaze]

Thank you for waiting, just got back from a little vacation. I'm working on the PR in #1374. I think you can only link the issue if you're a maintainer? But feel free to close this issue too, I'm just not sure how you like to organize this project.