Update docker.md

docs/docker.md

@@ -202,6 +202,63 @@ docker rm -f onedrive
 
 ## Advanced Usage
 
+### Run OneDrive with custom CLI arguments.
+
+Inside the Docker image, the entrypoint always starts the client with the arguments:
+```
+--confdir /onedrive/conf --syncdir /onedrive/data
+```
+
+If you want to add custom CLI arguments to the inner `onedrive` process of the container, you can do it like this or equivalently (notice `--other-custom-args` after the image name):
+
+```
+docker run \
+  -it \
+  --name onedrive \
+  --userns host \
+  -v ${ONEDRIVE_DIR}/conf:/onedrive/conf \
+  -v ${ONEDRIVE_DIR}/data:/onedrive/data \
+  -v ${ONEDRIVE_DIR}/logs:/onedrive/logs \
+  -l io.containers.autoupdate=image \
+  --restart unless-stopped \
+  --health-cmd "sh -c '[ -s /onedrive/conf/items.sqlite3-wal ]'" \
+  --health-interval 60s \
+  --health-retries 2 \
+  --health-timeout 5s \
+  docker.io/driveone/onedrive:latest \
+  --other-custom-args
+```
+
+> [!IMPORTANT]
+> Command-line flags override anything in the config file, so if you set `sync_dir` in the config, it will be superseded by the CLI flag. 
+> Moreover, if you override the container’s command and forget to include those arguments, the client will not have any information regarding the `sync_dir` and `conf_dir` location and thus it will fall back to `~/OneDrive` inside the container, which will look like it is “ignoring” your setting.
+
+So, if you use custom CLI arguments on the inner Docker process, you are skipping the automated inclusion of arguments `--confdir /onedrive/conf --syncdir /onedrive/data`, so you will probably need to explicitly add them again to your `docker run` command. The previous example would look like this if you apply these best practices:
+
+
+```
+docker run \
+  -it \
+  --name onedrive \
+  --userns host \
+  -v ${ONEDRIVE_DIR}/conf:/onedrive/conf \
+  -v ${ONEDRIVE_DIR}/data:/onedrive/data \
+  -v ${ONEDRIVE_DIR}/logs:/onedrive/logs \
+  -l io.containers.autoupdate=image \
+  --restart unless-stopped \
+  --health-cmd "sh -c '[ -s /onedrive/conf/items.sqlite3-wal ]'" \
+  --health-interval 60s \
+  --health-retries 2 \
+  --health-timeout 5s \
+  docker.io/driveone/onedrive:latest \
+  --other-custom-args \
+  --sync-dir "/onedrive/data" \
+  --conf-dir "/onedrive/conf" 
+```
+
+Notice the explicit inclusion of `--sync-dir "/onedrive/data"` `--conf-dir "/onedrive/conf"` after the image name. 
+
+
 ### How to use Docker-compose
 You can utilise `docker-compose` if available on your platform if you are able to use docker compose schemas > 3.
 
@@ -432,4 +489,4 @@ RUN echo "ja_JP.UTF-8 UTF-8" > /etc/locale.gen && \
 
 ENV LC_ALL ja_JP.UTF-8
 ```
-The above example changes the Docker container to support Japanese. To support your local language, change `ja_JP.UTF-8` to the required entry.
+The above example changes the Docker container to support Japanese. To support your local language, change `ja_JP.UTF-8` to the required entry.