test: a lab that runs a real desktop where no VM can exist

The development host is a VM without /dev/kvm, so a candidate desktop cannot be given a virtual machine here. It gets a systemd container instead, with the session nested inside a headless sway so that grim can photograph it and sway's IPC can aim a real pointer at it. Plasma 6.3.6 comes up in it, software-rendered, at 1920x1080. Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-10 07:59:46 -05:00
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+# Classroom v2 test lab: a full Debian 13 Plasma 6 desktop, running under
+# systemd, inside a container. It exists because the development host is
+# itself a VM with no /dev/kvm, so a real virtual machine cannot be created
+# here. See docs/classroom-v2-experiment.md.
+#
+#   docker build -f tools/lab/Dockerfile.plasma -t classroom-v2-lab:plasma .
+#   tools/lab/lab up
+#
+FROM debian:trixie
+
+ENV DEBIAN_FRONTEND=noninteractive
+ENV container=docker
+
+# systemd, so the session is supervised the way it would be on a real machine
+RUN apt-get update && apt-get install -y systemd systemd-sysv dbus dbus-user-session \
+ && rm -rf /var/lib/apt/lists/*
+
+# The desktop under test.
+RUN apt-get update && apt-get install -y \
+      plasma-desktop plasma-workspace kwin-wayland \
+      plasma-nm plasma-pa \
+ && rm -rf /var/lib/apt/lists/*
+
+# Software rendering, X11 apps, fonts, and the tools the lab drives it with.
+RUN apt-get update && apt-get install -y --no-install-recommends \
+      libgl1-mesa-dri libglx-mesa0 mesa-utils-bin libegl-mesa0 \
+      xwayland \
+      fonts-noto-core fonts-dejavu-core fonts-liberation \
+      kde-cli-tools qdbus-qt6 \
+      sway swaybg grim wtype foot \
+      python3 python3-gi gir1.2-gtk-3.0 \
+      curl ca-certificates gnupg procps psmisc less vim-tiny socat jq \
+ && rm -rf /var/lib/apt/lists/*
+
+RUN useradd -m -u 1000 -s /bin/bash classroom \
+ && usermod -aG video,render,audio classroom \
+ && passwd -d classroom \
+ && mkdir -p /run/user/1000 && chown classroom:classroom /run/user/1000 \
+ && systemctl enable systemd-logind
+
+# Linger so the classroom user's systemd instance starts with the container,
+# which is exactly how the appliance would run.
+RUN mkdir -p /var/lib/systemd/linger && touch /var/lib/systemd/linger/classroom
+
+STOPSIGNAL SIGRTMIN+3
+CMD ["/sbin/init"]
+
+# Screenshots. KWin's org.kde.KWin.ScreenShot2 only answers callers it
+# recognises by path, and Spectacle is one of them, so this is the
+# sanctioned way to capture a KWin session that has no outer compositor.
+RUN apt-get update && apt-get install -y --no-install-recommends kde-spectacle \
+ && rm -rf /var/lib/apt/lists/*