name : run-snapd-from-snap #!/bin/bash # # This script will try to find a suiteable snapd snap and start # snapd and its associated services from it. set -eux # run_on_unseeded will run snapd on an unseeded system. The snapd snap # is expected to have been mounted and current link is expected to # have been created by the initramfs. run_on_unseeded() { SNAPD_BASE_DIR="/snap/snapd/current" if ! mountpoint -q "$SNAPD_BASE_DIR"; then # Compatibility with old way where we had a duplicated mount in /run # and "current" link was not created by initramfs. SNAPD_BASE_DIR="/run/mnt/snapd" # We need to initialize /snap/snapd/current symlink so that the # dynamic linker # /snap/snapd/current/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 # is available to run snapd. mkdir -p /snap/snapd ln -sf "${SNAPD_BASE_DIR}" /snap/snapd/current fi # snapd will write all its needed snapd.{service,socket} # units and restart once it seeded the snapd snap. We create # a systemd socket unit so that systemd owns the socket, otherwise # the socket file would be removed by snapd on exit and the snapd.seeded # service will fail because it has nothing to talk to anymore. socket_args=() while IFS= read -r socket; do socket_args+=(--socket-property) socket_args+=("$socket") done < <(grep -E '^ListenStream=.+' /snap/snapd/current/lib/systemd/system/snapd.socket) systemd-run --unit=snapd-seeding --service-type=notify \ "${socket_args[@]}" \ --property KeyringMode=inherit "$SNAPD_BASE_DIR"/usr/lib/snapd/snapd # we need to start the snapd service from above explicitly, systemd-run # only enables the socket but does not start the service. systemctl start --wait snapd-seeding.service # at this point the snapd.socket is available systemctl stop snapd-seeding.socket # At this point snap is available and seeding is at the point where # were snapd is installed and restarted successfully. Show progress # now. Even without showing progress we *must* wait here until # seeding is done to ensure that console-conf is only started # after this script has finished. # (redirect stdin because that is what snap checks for pty) /usr/bin/snap watch --last=seed < /dev/console | tee -a /dev/console } # Unseeded systems need to be seeded first, this will start snapd # and snapd will restart itself after the seeding. # systemctl status returns exit code 4 for missing services, and 3 for # non-running services snapdExists=0 systemctl status snapd.service || snapdExists=$? if [ ! -e /var/lib/snapd/state.json ] || [ $snapdExists -eq 4 ] ; then if ! run_on_unseeded; then echo "cannot run snapd from the seed" exit 1 fi exit 0 fi