Script that checks if a container needs package update.

tools/containers_check_update_rebuild_switch.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+set -euxv
+
+echo "$@"
+
+function fail_one()
+{
+    echo >&2 "FAILURE when processing $CONTAINER_ID ($NAME_OF_CONTAINER), step: " "$@"
+    RC=1
+}
+
+
+RC=0
+
+for CONTAINER_ID
+do
+
+    echo "Processing $CONTAINER_ID"
+    TMPFILE=$(mktemp)
+    docker exec -u root $CONTAINER_ID bash -c "export LC_ALL=C ; apt-get update ; apt-get upgrade --dry-run" | tee $TMPFILE
+    trap "rm $TMPFILE" EXIT
+    if grep "0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded." $TMPFILE
+    then
+	echo "No update needed."
+	continue
+    fi
+
+    PATH_OF_CONTAINER="$( docker inspect --format='{{ index .Config.Labels "com.docker.compose.project.working_dir" }}' $CONTAINER_ID )"
+    NAME_OF_CONTAINER="$( docker inspect --format='{{ .Name }}' $CONTAINER_ID )"
+    cd $PATH_OF_CONTAINER
+    docker-compose pull || { fail_one "pull" ; continue ; }
+    docker-compose build || { fail_one "build" ; continue ; }
+    docker-compose up -d || { fail_one "switch to newly built container" ; continue ; }
+
+done