04.12 update lesson-6.md

Clear the Cache and Cache path

Author: JavaScriptonit

Course/lesson-6.md

@@ -43,3 +43,16 @@
  * `cache_dir = "/cache"` - add same location to cache as volume directory
  * `:wq` - Save the file
 
+### Clear the Cache:
+* Manually with button "Clear runner caches"
+ * The old cache is not deleted
+ * Cache name will be updated and used instead
+ * Have to delete manually files from the Runner storage
+ * Format "cache-index", index is incremented by one
+* Change the value for the cache key in yml file
+
+* `$ docker volume ls` - reference to the physical location on this machine where cache is stored
+* `$ runner-ieinwck3-project-40450508-concurrent-0-cache-3c3f060a0374fc8bc39395164f415a70` - the location "/var/lib/docker/volumes/runner-ieinwck3-project-40450508-concurrent-0-cache-3c3f060a0374fc8bc39395164f415a70/_data"
+* `sudo ls /var/lib/docker/volumes/runner-ieinwck3-project-40450508-concurrent-0-cache-3c3f060a0374fc8bc39395164f415a70/_data/JavaScriptonit/mynodeapp-cicd-project` - path of the cache
+* [Where the caches are stored](https://docs.gitlab.com/ee/ci/caching/) - for Shell, Docker and Docker Machine
+*