image prune: support removing external containers

Support removing external containers (e.g., build containers) during
image prune.

Fixes: #11472
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

test/system/040-ps.bats

@@ -92,24 +92,38 @@ load helpers
     # Force a buildah timeout; this leaves a buildah container behind
     PODMAN_TIMEOUT=5 run_podman 124 build -t thiswillneverexist - <<EOF
 FROM $IMAGE
+RUN touch /intermediate.image.to.be.pruned
 RUN sleep 30
 EOF
 
     run_podman ps -a
-    is "${#lines[@]}" "1" "podman ps -a does not see buildah container"
+    is "${#lines[@]}" "1" "podman ps -a does not see buildah containers"
 
     run_podman ps --external -a
-    is "${#lines[@]}" "2" "podman ps -a --external sees buildah container"
+    is "${#lines[@]}" "3" "podman ps -a --external sees buildah containers"
     is "${lines[1]}" \
        "[0-9a-f]\{12\} \+$IMAGE *buildah .* seconds ago .* storage .* ${PODMAN_TEST_IMAGE_NAME}-working-container" \
        "podman ps --external"
 
-    cid="${lines[1]:0:12}"
-
     # 'rm -a' should be a NOP
     run_podman rm -a
     run_podman ps --external -a
-    is "${#lines[@]}" "2" "podman ps -a --external sees buildah container"
+    is "${#lines[@]}" "3" "podman ps -a --external sees buildah containers"
+
+    # Cannot prune intermediate image as it's being used by a buildah
+    # container.
+    run_podman image prune -f
+    is "$output" "" "No image is pruned"
+
+    # --external for removing buildah containers.
+    run_podman image prune -f --external
+    is "${#lines[@]}" "1" "Image used by build container is pruned"
+
+    # One buildah container has been removed.
+    run_podman ps --external -a
+    is "${#lines[@]}" "2" "podman ps -a --external sees buildah containers"
+
+    cid="${lines[1]:0:12}"
 
     # We can't rm it without -f, but podman should issue a helpful message
     run_podman 2 rm "$cid"

test/system/330-corrupt-images.bats

@@ -78,7 +78,7 @@ function _corrupt_image_test() {
 
         # Run the requested command. Confirm it succeeds, with suitable warnings
         run_podman $*
-        is "$output" ".*error determining parent of image.*ignoring the error" \
+        is "$output" ".*Failed to determine parent of image.*ignoring the error" \
            "$* with missing $what_to_rm"
 
         run_podman images -a --noheading