1 files changed, 46 insertions, 0 deletions
diff --git a/global/overlay/usr/local/bin/docker-cleanup b/global/overlay/usr/local/bin/docker-cleanup
new file mode 100755
index 0000000..f46942b
--- /dev/null
+++ b/global/overlay/usr/local/bin/docker-cleanup
@@ -0,0 +1,46 @@
+#!/bin/sh
+# Cleanup docker files: untagged containers and images.
+#
+# Use `docker-cleanup -n` for a dry run to see what would be deleted.
+
+untagged_containers() {
+	# Print containers using untagged images: $1 is used with awk's print: 0=line, 1=column 1.
+	# NOTE: "[0-9a-f]{12}" does not work with GNU Awk 3.1.7 (RHEL6).
+	#       Ref: https://github.com/blueyed/dotfiles/commit/a14f0b4b#commitcomment-6736470
+	docker ps -a | tail -n +2 | awk '$2 ~ "^[0-9a-f]+$" {print $'$1'}'
+}
+
+untagged_images() {
+	# Print untagged images: $1 is used with awk's print: 0=line, 3=column 3.
+	# NOTE: intermediate images (via -a) seem to only cause
+	# "Error: Conflict, foobarid wasn't deleted" messages.
+	# Might be useful sometimes when Docker messed things up?!
+	# docker images -a | awk '$1 == "<none>" {print $'$1'}'
+	docker images | tail -n +2 | awk '$1 == "<none>" {print $'$1'}'
+}
+
+# Dry-run.
+if [ "$1" = "-n" ]; then
+	echo "=== Containers with uncommitted images: ==="
+	untagged_containers 0
+	echo
+
+	echo "=== Uncommitted images: ==="
+	untagged_images 0
+
+	exit
+fi
+if [ -n "$1" ]; then
+	echo "Cleanup docker files: remove untagged containers and images."
+	echo "Usage: ${0##*/} [-n]"
+	echo "   -n: dry run: display what would get removed."
+	exit 1
+fi
+
+# Remove containers with untagged images.
+echo "Removing containers:" >&2
+untagged_containers 1 | xargs --no-run-if-empty docker rm --volumes=true
+
+# Remove untagged images
+echo "Removing images:" >&2
+untagged_images 3 | xargs --no-run-if-empty docker rmi