Support docker installation via snap, e.g. Ubuntu 22.04

lib/functions.sh

@@ -11,6 +11,22 @@ detectCompose() {
 	fi
 }
 
+# https://unix.stackexchange.com/questions/539147
+systemctl-exists() {
+	[ $(systemctl list-unit-files "${1}*" | wc -l) -gt 3 ]
+}
+
+dockerUnitName() {
+	if systemctl-exists docker.service; then
+		echo "docker.service"
+	elif systemctl-exists snap.docker.dockerd.service; then
+		echo "snap.docker.dockerd.service"
+	else
+		log ERROR "Unable to detect docker systemd unit."
+		fail_and_report 1 "Unable to detect docker systemd unit."
+	fi
+}
+
 exitIfNotRoot() {
   if [ "$EUID" -ne 0 ]; then
     log "ERROR" "Please run as root"

lib/setup-bridgehead-units.sh

@@ -40,6 +40,12 @@ cp -v \
     lib/systemd/bridgehead-update\@.timer \
     /etc/systemd/system/
 
+log INFO "Setting Docker unit ..."
+
+for file in $(find /etc/systemd/system -mindepth 1 -maxdepth 1 -type f -name "bridgehead*"); do
+	sed -i "s/DOCKER_UNIT_NAME/$(dockerUnitName)/g" $file
+done
+
 systemctl daemon-reload
 
 log INFO "Trying to update your bridgehead ..."

lib/systemd/bridgehead@.service

@@ -1,6 +1,6 @@
 [Unit]
 Description=Bridgehead (%i)
-Requires=docker.service
+Requires=DOCKER_UNIT_NAME
 
 [Service]
 User=bridgehead