From 45892f99bc723a269d476c8b41059586ca169351 Mon Sep 17 00:00:00 2001
From: Tom Stockton <tom@stocktons.org.uk>
Date: Thu, 14 Jul 2016 11:16:00 +0100
Subject: [PATCH] Add flag to not garbage collect any containers.

---
 README.md |  7 +++++++
 docker-gc | 13 ++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index ed050d0..9a3bbcc 100644
--- a/README.md
+++ b/README.md
@@ -96,6 +96,13 @@ mariadb-data
 drunk_goodall
 ```
 
+If you would prefer to not garbage collect any containers at all then
+you can do this by setting the environment variable below:
+
+```
+REMOVE_CONTAINERS=0 docker-gc
+```
+
 ### Forcing deletion of images that have multiple tags
 
 By default, docker will not remove an image if it is tagged in multiple
diff --git a/docker-gc b/docker-gc
index 735d4f0..284a7b0 100755
--- a/docker-gc
+++ b/docker-gc
@@ -44,6 +44,7 @@ set -o errexit
 
 GRACE_PERIOD_SECONDS=${GRACE_PERIOD_SECONDS:=3600}
 STATE_DIR=${STATE_DIR:=/var/lib/docker-gc}
+REMOVE_CONTAINERS=${REMOVE_CONTAINERS:=1}
 FORCE_CONTAINER_REMOVAL=${FORCE_CONTAINER_REMOVAL:=0}
 FORCE_IMAGE_REMOVAL=${FORCE_IMAGE_REMOVAL:=0}
 DOCKER=${DOCKER:=docker}
@@ -252,11 +253,13 @@ if [[ $FORCE_CONTAINER_REMOVAL -gt 0 ]]; then
     FORCE_CONTAINER_FLAG="-f"
 fi
 # Reap containers.
-if [[ $DRY_RUN -gt 0 ]]; then
-    container_log "The following container would have been removed" containers.reap
-else
-    container_log "Removing containers" containers.reap
-    xargs -n 1 $DOCKER rm $FORCE_CONTAINER_FLAG --volumes=true < containers.reap &>/dev/null || true
+if [[ $REMOVE_CONTAINERS -gt 0 ]]; then
+  if [[ $DRY_RUN -gt 0 ]]; then
+      container_log "The following container would have been removed" containers.reap
+  else
+      container_log "Removing containers" containers.reap
+      xargs -n 1 $DOCKER rm $FORCE_CONTAINER_FLAG --volumes=true < containers.reap &>/dev/null || true
+  fi
 fi
 
 # Use -f flag on docker rmi command; forces removal of images that have multiple tags