Add docker configuration guide

docs/guides/configuration-guide/services/docker.md

@@ -0,0 +1,34 @@
+---
+sidebar_label: Docker
+---
+
+# Docker
+
+With the `osism.services.docker` role, it is possible to manage Docker.
+
+## Configure logging drivers
+
+Docker documentation: https://docs.docker.com/config/containers/logging/configure/
+
+The role currently supports the following parameters with their respective defaults.
+
+```yaml
+docker_log_driver: "json-file"
+docker_log_level: info
+docker_log_opts:
+  max-size: 10m
+  max-file: 3
+```
+
+The log driver to be used can be configured with `docker_log_driver`. By default,
+`json-file` is used. The log driver writes all logs of a container to a JSON file
+in `/var/lib/docker/containers`. All supported log drivers can be found in the
+[Docker documentation](https://docs.docker.com/config/containers/logging/configure/#supported-logging-drivers).
+
+The log level can be configured via `docker_log_level`.
+
+Parameters for the log driver used can be set with the `docker_log_opts` dictionary.
+By default, the maximum size of a JSON file is set to 10 MByte with `max-size: 10m`.
+If it contains more, the file is rotated.
+
+Furthermore, `max-file: 3` specifies that up to 3 files should be available.