Merge pull request #2315 from tzerber/volume-clarification

Clarify Readme on bind volumes to avoid `apps` / `custom_apps` mishaps

README.md

@@ -87,13 +87,38 @@ If you want to use named volumes for all of these, it would look like this:
 ```console
 $ docker run -d \
 -v nextcloud:/var/www/html \
--v apps:/var/www/html/custom_apps \
+-v custom_apps:/var/www/html/custom_apps \
 -v config:/var/www/html/config \
 -v data:/var/www/html/data \
 -v theme:/var/www/html/themes/<YOUR_CUSTOM_THEME> \
 nextcloud
 ```
 
+If you'd prefer to use bind mounts instead of named volumes, for instance, when working with different device or network mounts for user data files and configuration:
+```console
+$ docker run -d \
+-v /path/on/host/to/folder/nextcloud:/var/www/html \
+-v /path/on/host/to/folder/custom_apps:/var/www/html/custom_apps \
+-v /path/on/host/to/folder/config:/var/www/html/config \
+-v /path/on/host/to/folder/data:/var/www/html/data \
+-v /path/on/host/to/folder/theme:/var/www/html/themes/<YOUR_CUSTOM_THEME> \
+nextcloud
+```
+
+Here’s the same example using Docker's more detailed `--mount`. Note that with `-v` or `--volume`, the specified folders are created automatically if they don't exist. However, when using `--mount` for bind mounts, the directories must already exist on the host, or Docker will return an error.
+```console
+$ docker run -d \
+--mount type=bind,source=/path/on/host/to/folder/nextcloud,target=/var/www/html \
+--mount type=bind,source=/path/on/host/to/folder/custom_apps,target=/var/www/html/custom_apps \
+--mount type=bind,source=/path/on/host/to/folder/config,target=/var/www/html/config \
+--mount type=bind,source=/path/on/host/to/folder/data,target=/var/www/html/data \
+--mount type=bind,source=/path/on/host/to/folder/theme,target=/var/www/html/themes/<YOUR_CUSTOM_THEME> \
+nextcloud
+```
+The examples above use figurative directory `/path/on/host/to/folder/` for bind mounts. Please modify the paths by using either a relative or absolute path.
+
+NOTE: Do not confuse the `apps` and `custom_apps` folders. These folders contain different sets of apps, and mixing them will result in a broken installation. The former contains "shipped" apps, which come with Nextcloud Server. The latter contains apps you install from the App Store.
+
 ### Custom volumes
 
 If mounting additional volumes under `/var/www/html`, you should consider: