Prepare for auto-pruning

lib/tasks/mrsk/images.rake

@@ -0,0 +1,10 @@
+require_relative "setup"
+
+namespace :mrsk do
+  namespace :images do
+    desc "Prune unused images older than 30 days"
+    task :prune do
+      on(MRSK_CONFIG.servers) { execute "docker image prune -f --filter 'until=720h'" }
+    end
+  end
+end