From 4ce79429c63d8b24138b3433144f68310dd9fac8 Mon Sep 17 00:00:00 2001
From: Michael de Wit <michael@drillster.com>
Date: Wed, 1 Feb 2017 14:42:43 +0100
Subject: [PATCH] Add [NO CACHE] and [CLEAR CACHE] to commit message options to
 control plugin behavior, use separate cache for matrix jobs. Fixes #3

---
 DOCS.md   |  6 ++++++
 README.md |  1 +
 cacher.sh | 26 +++++++++++++++++++-------
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/DOCS.md b/DOCS.md
index bf7f917..becf55d 100644
--- a/DOCS.md
+++ b/DOCS.md
@@ -35,3 +35,9 @@ pipeline:
 ```
 
 The example above illustrates a typical Node.js project Drone configuration. It caches the `./node_modules` directory to a mounted volume on the host system: `/tmp/cache`. This prevents `npm` from downloading and installing the dependencies for every build.
+
+## Clearing Cache
+Should you want to clear the cache for a project, you can do so by including `[CLEAR CACHE]` in the commit message. The entire cache folder for the project will be cleared before it is restored. The rebuilding of cache will proceed as normal.
+
+## Skipping Cache
+If you want to run a build without using cache, put `[NO CACHE]` in the commit message. Both the restoring and rebuilding of cache will be skipped. Your cache will remain intact.
\ No newline at end of file
diff --git a/README.md b/README.md
index da5db5e..90fff45 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,7 @@ docker run --rm \
   -e PLUGIN_MOUNT="./node_modules" \
   -e DRONE_REPO_OWNER="foo" \
   -e DRONE_REPO_NAME="bar" \
+  -e DRONE_JOB_NUMBER=0 \
   -v $(pwd):$(pwd) \
   -v /tmp/cache:/cache \
   -w $(pwd) \
diff --git a/cacher.sh b/cacher.sh
index f14be91..e2f59d3 100644
--- a/cacher.sh
+++ b/cacher.sh
@@ -2,24 +2,36 @@
 
 if [ -z "$PLUGIN_MOUNT" ]; then
     echo "Specify folders to cache in the mount property! Plugin won't do anything!"
-    exit 0;
+    exit 0
+fi
+
+if [[ $DRONE_COMMIT_MESSAGE == *"[CLEAR CACHE]"* && -n "$PLUGIN_RESTORE" && "$PLUGIN_RESTORE" == "true" ]]; then
+    if [ -d "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME" ]; then
+        echo "Found [CLEAR CACHE] in commit message, clearing cache!"
+        rm -rf "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME"
+    fi
+fi
+
+if [[ $DRONE_COMMIT_MESSAGE == *"[NO CACHE]"* ]]; then
+    echo "Found [NO CACHE] in commit message, skipping cache restore and rebuild!"
+    exit 0
 fi
 
 IFS=','; read -ra SOURCES <<< "$PLUGIN_MOUNT"
-if [ -n "$PLUGIN_REBUILD" ]; then
+if [[ -n "$PLUGIN_REBUILD" && "$PLUGIN_REBUILD" == "true" ]]; then
     # Create cache
     for source in "${SOURCES[@]}"; do
         echo "Rebuilding cache for $source..."
-        mkdir -p "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$source" && \
-            rsync -aHAX --delete "$source/" "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$source"
+        mkdir -p "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$DRONE_JOB_NUMBER/$source" && \
+            rsync -aHAX --delete "$source/" "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$DRONE_JOB_NUMBER/$source"
     done
-elif [ -n "$PLUGIN_RESTORE" ]; then
+elif [[ -n "$PLUGIN_RESTORE" && "$PLUGIN_RESTORE" == "true" ]]; then
     # Restore from cache
     for source in "${SOURCES[@]}"; do
-        if [ -d "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$source" ]; then
+        if [ -d "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$DRONE_JOB_NUMBER/$source" ]; then
             echo "Restoring cache for $source..."
             mkdir -p "$source" && \
-                rsync -aHAX --delete "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$source/" "$source"
+                rsync -aHAX --delete "/cache/$DRONE_REPO_OWNER/$DRONE_REPO_NAME/$DRONE_JOB_NUMBER/$source/" "$source"
         else
             echo "No cache for $source"
         fi