semaphore: switch to Ubuntu LTS to get back coverage

As Ubuntu's autopkgtest cloud infra is disabled, we are lacking coverage for
Ubuntu's tests, which is problematic as regressions there are costly,
especially as the plan for Resolute is to upload stable point releases.
Switch the Semaphore job to cover it. It will give approximate coverage
for Debian which is sufficient, and mkosi's tests provide the rest.

.semaphore/semaphore-runner.sh

@@ -4,8 +4,8 @@
 set -eux
 set -o pipefail
 
-DISTRO="${DISTRO:-debian}"
-RELEASE="${RELEASE:-trixie}"
+DISTRO="${DISTRO:-ubuntu}"
+RELEASE="${RELEASE:-resolute}"
 SALSA_URL="${SALSA_URL:-https://salsa.debian.org/systemd-team/systemd.git}"
 BRANCH="${BRANCH:-debian/master}"
 ARCH="${ARCH:-amd64}"
@@ -32,35 +32,40 @@ create_container() {
 lxc.apparmor.profile = unconfined
 lxc.mount.auto =
 lxc.mount.auto = proc:mixed sys:mixed
-lxc.init.cmd = /sbin/init systemd.unified_cgroup_hierarchy=1
+lxc.init.cmd = /sbin/init systemd.unified_cgroup_hierarchy=1 systemd.mask=netplan-configure.service
 EOF
 
     sudo lxc-start -n "$CONTAINER" --define "lxc.include=/var/lib/lxc/$CONTAINER/config.systemd_upstream"
 
-    # enable source repositories so that apt-get build-dep works
     sudo lxc-attach -n "$CONTAINER" -- sh -ex <<EOF
+# enable source repositories so that apt-get build-dep works
 sed 's/^deb/deb-src/' /etc/apt/sources.list >>/etc/apt/sources.list.d/sources.list
-echo "deb http://deb.debian.org/debian $RELEASE-backports main" >/etc/apt/sources.list.d/backports.list
 # We might attach the console too soon
 until systemctl --quiet --wait is-system-running; do sleep 1; done
+# LXC uses a veth
+mkdir -p /etc/systemd/network/
+cat >/etc/systemd/network/10-eth0.network <<NETWORK
+[Match]
+Name=eth0
+[Network]
+DHCP=yes
+KeepConfiguration=yes
+NETWORK
+systemctl unmask systemd-networkd
+systemctl enable --now systemd-networkd
+networkctl reload
+/usr/lib/systemd/systemd-networkd-wait-online --interface=eth0:routable --ipv4 --timeout=60
 # Manpages database trigger takes a lot of time and is not useful in a CI
 echo 'man-db man-db/auto-update boolean false' | debconf-set-selections
 # Speed up dpkg, image is thrown away after the test
 mkdir -p /etc/dpkg/dpkg.cfg.d/
 echo 'force-unsafe-io' >/etc/dpkg/dpkg.cfg.d/unsafe_io
-# For some reason, it is necessary to run this manually or the interface won't be configured
-# Note that we avoid networkd, as some of the tests will break it later on
-dhclient
 apt-get -q --allow-releaseinfo-change update
 apt-get -y dist-upgrade
 apt-get install -y eatmydata
-# The following four are needed as long as these deps are not covered by Debian's own packaging
-apt-get install -y tree libpwquality-dev rpm libcurl4-openssl-dev libarchive-dev
-# autopkgtest doesn't consider backports
-apt-get install -y -t $RELEASE-backports debhelper
+# The following are needed as long as these deps are not covered by Debian's own packaging
+apt-get install -y tree rpm
 apt-get purge --auto-remove -y unattended-upgrades
-systemctl unmask systemd-networkd
-systemctl enable systemd-networkd
 EOF
     sudo lxc-stop -n "$CONTAINER"
 }

.semaphore/semaphore.yml

@@ -3,7 +3,7 @@
 # vi: ts=2 sw=2 et:
 
 version: v1.0
-name: Debian autopkgtest (LXC)
+name: autopkgtest (LXC)
 agent:
   machine:
     type: e1-standard-2
@@ -21,7 +21,7 @@ blocks:
   - name: "Setup & test"
     task:
       jobs:
-        - name: "Install dependencies & run the Debian autopkgtest"
+        - name: "Install dependencies & run the autopkgtest"
           commands:
             - checkout --use-cache
             - .semaphore/semaphore-runner.sh SETUP