Make containers persistent, recreate them only when needed

launcher-image/src/run-mirror-update

@@ -26,6 +26,9 @@ trap finish EXIT
 volume_prefix=cloner
 clone_prefix=cloner-runner
 
+# last version of image
+last_version=$(docker images $mirror_image --no-trunc --quiet)
+
 name=${1:-}
 [ -n "$name" ] || die "No volume specified"
 
@@ -47,21 +50,28 @@ then
 fi
 unset lines
 
-# does it exist?
+# check if volume does exist?
-docker ps --quiet -a --no-trunc --filter name=^/$container_name$ > $scratch/existing
-lines=$(wc -l $scratch/existing | cut -d' ' -f1)
-
-if ! [ $lines -eq 0 ] 
-then
-	log "Conflicting container exists, removing.."
-	docker rm $(cat $scratch/existing)
-fi
-
-unset lines
-
-# does volume exist?
 docker volume inspect $name > /dev/null 2>&1 || die "Volume '$name' does not exist - exiting!"
 
+# does it exist?
+image_version=$(docker inspect --format='{{.Image}}' $container_name 2>/dev/null || true)
+
+# do I need to recreate image?
+if ! [ "x$image_version" = "x$last_version" ] 
+then
+	# not empty string - need to delete first
+	if [ -n "$image_version" ] 
+	then		
+		log "Conflicting container exists, removing.."
+		docker rm $container_name
+	fi
+	# create new container
+	log "Creating new version of container.."
+	docker create -v $name:/data --name $container_name $mirror_image
+fi
+
+
 log "Running container of update process..."
-docker run -v $name:/data --name $container_name --rm $mirror_image | while read line; do log "$line"; done
+docker start -a $container_name | while read line; do log "$line"; done
 log "Finished."
+