feat: allow config var for slug override

README.md

@@ -34,6 +34,7 @@ Plus, In addition to tarball & rsync, we also do not re-create another tarball f
   - [Adjust compression level](#adjust-compression-level)
   - [Continue to cache on failed builds](#continue-to-cache-on-failed-builds)
   - [Multi-threaded compression](#multi-threaded-compression)
+  - [Sharing caches between pipelines](#sharing-caches-between-pipelines)
   - [Auto deletion old caches](#auto-deletion-old-caches)
   - [Globs on paths](#globs-on-paths)
 - [Roadmap](#roadmap)
@@ -466,6 +467,31 @@ steps:
         compress-program: pigz # tar will use `pigz` to compress and benefit multithreading...
 ```
 
+## Sharing caches between pipelines
+
+If you have multiple pipelines that can benefit from referencing the same cache, you can use the `pipeline-slug-override` option:
+
+```yaml
+steps:
+  - name: ':jest: Run tests'
+    key: jest
+    command: yarn test --runInBand
+    plugins:
+      - gencer/cache#v2.4.11:
+        id: ruby # or ruby-3.0
+        backend: s3
+        key: "v1-cache-{{ id }}-{{ runner.os }}-{{ checksum 'Gemfile.lock' }}"
+        restore-keys:
+          - 'v1-cache-{{ id }}-{{ runner.os }}-'
+          - 'v1-cache-{{ id }}-'
+        compress: 2 # fast compression.
+        s3:
+          bucket: s3-bucket
+        paths:
+          - bundle/vendor
+        pipeline-slug-override: "other-pipeline" # other-pipeline references the same Gemfile.lock
+```
+
 ## Auto deletion old caches
 
 For tarballs, To keep caches and delete them in _for example_ 7 days, use `max: 7`.

lib/backends/rsync.bash

@@ -14,14 +14,14 @@ if [ -n "${BUILDKITE_PLUGIN_CACHE_RSYNC_PATH:-}" ]; then
 fi
 
 function restore() {
-  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/${BUILDKITE_PIPELINE_SLUG}"
+  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/$(pipeline_slug)"
 
   mkdir -p "${CACHE_PREFIX}/${CACHE_KEY}"
   rsync -a "$RSYNC_ARGS" "${CACHE_PREFIX}/${CACHE_KEY}/" .
 }
 
 function cache() {
-  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/${BUILDKITE_PIPELINE_SLUG}"
+  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/$(pipeline_slug)"
   mkdir -p "${CACHE_PREFIX}/${CACHE_KEY}/"
 
   if [ "${#paths[@]}" -eq 1 ]; then

lib/backends/s3.bash

@@ -65,7 +65,7 @@ fi
 
 function restore() {
   TAR_FILE="${CACHE_KEY}.${BK_TAR_EXTENSION}"
-  TKEY="${BUILDKITE_ORGANIZATION_SLUG}/${BUILDKITE_PIPELINE_SLUG}"
+  TKEY="${BUILDKITE_ORGANIZATION_SLUG}/$(pipeline_slug)"
   BUCKET="${BUILDKITE_PLUGIN_CACHE_S3_BUCKET}/${TKEY}"
   BK_AWS_FOUND=false
 
@@ -111,7 +111,7 @@ function restore() {
 
 function cache() {
   TAR_FILE="${CACHE_KEY}.${BK_TAR_EXTENSION}"
-  BUCKET="${BUILDKITE_PLUGIN_CACHE_S3_BUCKET}/${BUILDKITE_ORGANIZATION_SLUG}/${BUILDKITE_PIPELINE_SLUG}"
+  BUCKET="${BUILDKITE_PLUGIN_CACHE_S3_BUCKET}/${BUILDKITE_ORGANIZATION_SLUG}/$(pipeline_slug)"
   TAR_TARGETS=""
 
   if [ "${#paths[@]}" -eq 1 ]; then

lib/backends/tarball.bash

@@ -45,8 +45,8 @@ else
 fi
 
 function restore() {
-  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/${BUILDKITE_PIPELINE_SLUG}"
-  mkdir -p "${CACHE_PREFIX}/${BUILDKITE_PIPELINE_SLUG}"
+  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/$(pipeline_slug)"
+  mkdir -p "${CACHE_PREFIX}/$(pipeline_slug)"
   TAR_FILE="${CACHE_PREFIX}/${CACHE_KEY}.${BK_TAR_EXTENSION}"
   BK_TAR_FOUND=false
 
@@ -88,7 +88,7 @@ function restore() {
 }
 
 function cache() {
-  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/${BUILDKITE_PIPELINE_SLUG}"
+  CACHE_PREFIX="${BK_BASE_DIR}/${BUILDKITE_ORGANIZATION_SLUG}/$(pipeline_slug)"
 
   mkdir -p "${CACHE_PREFIX}"
   DAYS="${BUILDKITE_PLUGIN_CACHE_TARBALL_MAX:-}"

lib/shared.bash

@@ -88,3 +88,10 @@ function source_locating() {
 function cache_locating() {
   echo -e "${BK_LOG_PREFIX}🔍 Locating cache: $1"
 }
+
+# Value to be used as the pipeline slug
+# Returns:
+#   - String
+function pipeline_slug() {
+  echo ${BUILDKITE_PLUGIN_CACHE_PIPELINE_SLUG_OVERRIDE:-${BUILDKITE_PIPELINE_SLUG}}
+}