Add static website to caddy

docker/runner/README.md

@@ -0,0 +1,19 @@
+# runner
+
+After installation, individual runners must still be registered, e.g.:
+
+```
+docker run --rm -it -v gitlab_runner_config:/etc/gitlab-runner gitlab/gitlab-runner register --name <name>
+```
+
+An issue I encountered when trying to cache stuff between builds was the following warning in the runner logs:
+
+```
+ERROR: Could not create cache adapter               error=cache factory not found: factory for cache adapter "" was not registered
+```
+
+In order to make the runner able to create caches, register it like so:
+
+```
+docker run --rm -it -v gitlab_runner_config:/etc/gitlab-runner gitlab/gitlab-runner register --name <name> --docker-disable-cache=false -docker-cache-dir /cache --docker-volumes gitlab_runner_cache:/cache
+```