overthinkos/bootc-config

bootc-config -- bootc system configuration

Layer Properties

| Property | Value | |----------|-------| | Install files | task:, candy.yml |

Packages

• sway-systemd (RPM) -- Sway systemd integration

What this layer configures

1. tty1 autologin — writes /etc/systemd/system/[email protected]/autologin.conf so the user account logs in automatically on the first virtual console.
2. Default graphical target — systemctl set-default graphical.target so the OS boots into the desktop, not multi-user.
3. Global PipeWire + WirePlumber — enables pipewire.socket and wireplumber.service for every user session via systemctl --global enable.
4. Systemd user supervisord autostart (see next section) — ships /etc/systemd/user/supervisord.service + systemctl --global enable supervisord.service.
5. Linger for user — writes the sentinel file /var/lib/systemd/linger/user so the user's systemd instance starts at boot even without an interactive login.

Each systemctl cmd is suffixed || true because the directives succeed on live systems but may fail harmlessly during offline bootc assembly.

Running supervisord under systemd (bootc desktop autostart)

The selkies-desktop and openclaw metalayers compose supervisord service: fragments for every desktop program (labwc, chrome, swaync, waybar, selkies, traefik, …). On container images that's fine: ENTRYPOINT=supervisord starts the whole tree as PID 1. On bootc images, systemd is PID 1 and nothing wraps supervisord by default — the desktop would never come up.

This layer ships the missing wiring: a systemd user unit at /etc/systemd/user/supervisord.service that runs /usr/bin/supervisord -c /etc/supervisord.conf -n, guarded by ConditionFileIsExecutable=/usr/bin/supervisord + ConditionPathExists=/etc/supervisord.conf so it no-ops on bootc images that don't use supervisord. It's systemctl --global enabled so every user session started via tty1 autologin brings the desktop tier up.

StandardOutput=file:/tmp/supervisord-stdout.log is load-bearing

The unit declares:

StandardOutput=file:/tmp/supervisord-stdout.log
StandardError=file:/tmp/supervisord-stderr.log

These aren't for log collection — they're required for supervisord's per-program stdout_logfile=/dev/fd/1 entries to resolve. Under a systemd user service without this redirect, fd 1 points at the journal pipe; per-program dispatchers call open("/dev/fd/1") on that pipe and get ENXIO: No such device or address, causing every program to enter FATAL with the message unknown error making dispatchers for <name>: ENXIO. Redirecting stdout to a real file makes /dev/fd/1 openable. Also: the supervisord header template was separately changed from logfile=/dev/stdout to logfile=/tmp/supervisord.log for the same reason — see /charly-infrastructure:supervisord.

Linger sentinel file trick

loginctl enable-linger user is the usual way to enable linger, but it requires a running logind — which the offline bootc builder doesn't have. The equivalent effect is writing an empty file at /var/lib/systemd/linger/user. Existence alone enables linger at boot. This layer uses a mkdir: + cmd: touch pair to plant the sentinel (empty content doesn't pass write: validation).

Usage

# box.yml — this layer is included transitively via bootc-base
my-bootc-image:
  base: "quay.io/fedora/fedora-bootc:43"
  bootc: true
  distro: ["fedora:43", fedora]   # external bases need this — see /charly-image:image
  layers:
    - bootc-base
    - <other desktop layers>

Used In Images

Part of the /charly-distros:bootc-base composition layer. Used transitively in every bootc image:

• /charly-distros:bazzite — canonical worked example (exercises every piece of the supervisord + tty1 autologin + graphical target flow end-to-end)
• /charly-distros:aurora

Related Layers

• /charly-distros:bootc-base -- composition that includes this layer + sshd + qemu-guest-agent
• /charly-coder:sshd -- SSH server (also in bootc-base; NOPASSWD-sudo test handles the dual USER=root/1000 context)
• /charly-distros:qemu-guest-agent -- QEMU agent (also in bootc-base)
• /charly-infrastructure:supervisord -- the init system that this layer wires into systemd on bootc
• /charly-selkies:selkies-desktop-layer -- the 19-sublayer desktop metalayer that this autostart brings up

Related Skills

• /charly-vm:vm -- VM lifecycle + the /dev:/dev mount requirement for bootc install to-disk
• /charly-image:image -- the external-base distro: requirement
• /charly-build:generate -- the empty-systemd-services-stage fix that makes bootc images with only packaged systemd units (unified service: entries using use_packaged:) build cleanly
• /charly-eval:eval -- dual-mode USER context authoring gotcha (test #11)
• /charly-image:layer -- layer authoring reference

When to Use This Skill

Use when the user asks about:

• Bootc image autologin configuration
• systemd graphical target setup
• pipewire/wireplumber system service enablement
• tty1 autologin in bootable containers
• How supervisord starts on a bootc image (systemd user service + StandardOutput=file: trick)
• The /var/lib/systemd/linger/user sentinel-file pattern
• Symptoms like unknown error making dispatchers for <name>: ENXIO in supervisord logs