tcwg-cleanup-stale-containers: Reword removal of unused images

... to avoid spurious warning from removing untagged images
that are used by non-running containers.

Change-Id: I6d8f665c2c1559cd7826236cbfac16cbc48e1f31

1 files changed, 14 insertions, 5 deletions

diff --git a/tcwg-cleanup-stale-containers.sh b/tcwg-cleanup-stale-containers.sh
index 97fd3f9c..d69c8c1d 100755
--- a/tcwg-cleanup-stale-containers.sh
+++ b/tcwg-cleanup-stale-containers.sh
@@ -75,13 +75,22 @@ if [ x"$(docker volume ls -q -f dangling=true)" != x"" ]; then
     fi
 fi
 
-if [ x"$(docker images -q -f dangling=true)" != x"" ]; then
-    echo "Removing untagged images"
-    echo "Increasing exit code by 4 to indicate untagged images"
+rm_images=()
+for image in $(docker images -q -f dangling=true); do
+    if ! docker ps -a --format "{{.Image}}" | grep -q $image; then
+	rm_images=("${rm_images[@]}" $image)
+    fi
+done
+
+if [ ${#rm_images[@]} != 0 ]; then
+    echo "Removing unused images"
+    echo "Increasing exit code by 4 to indicate unused images"
     status="$(($status+4))"
     if ! $dry_run; then
-	docker images -q -f dangling=true | xargs -i@ docker rmi @ | cat
-	echo "xargs docker rmi exit status: ${PIPESTATUS[3]}"
+	for image in "${rm_images[@]}"; do
+	    docker rmi $image | cat
+	    echo "docker rmi exit status: ${PIPESTATUS[0]}"
+	done
     else
         echo "DRY_RUN: NOT REMOVING UNTAGGED IMAGES"
     fi