/rclone_serve_docker

title: "rclone serve docker"
description: "Serve any remote on docker's volume plugin API."
versionIntroduced: v1.56
# autogenerated - DO NOT EDIT, instead edit the source code in cmd/serve/docker/ and as part of making a release run "make commanddocs"

> **Official documentation:** [https://rclone.org/commands/rclone_serve_docker/](https://rclone.org/commands/rclone_serve_docker/)

rclone serve docker

Serve any remote on docker's volume plugin API.

Synopsis

This command implements the Docker volume plugin API allowing docker to use rclone as a data storage mechanism for various cloud providers. rclone provides [docker volume plugin](/docker) based on it.

To create a docker plugin, one must create a Unix or TCP socket that Docker will look for when you use the plugin and then it listens for commands from docker daemon and runs the corresponding code when necessary. Docker plugins can run as a managed plugin under control of the docker daemon or as an independent native service. For testing, you can just run it directly from the command line, for example:

sudo rclone serve docker --base-dir /tmp/rclone-volumes --socket-addr localhost:8787 -vv

Running `rclone serve docker` will create the said socket, listening for commands from Docker to create the necessary Volumes. Normally you need not give the `--socket-addr` flag. The API will listen on the unix domain socket at `/run/docker/plugins/rclone.sock`. In the example above rclone will create a TCP socket and a small file `/etc/docker/plugins/rclone.spec` containing the socket address. We use `sudo` because both paths are writeable only by the root user.

If you later decide to change listening socket, the docker daemon must be restarted to reconnect to `/run/docker/plugins/rclone.sock` or parse new `/etc/docker/plugins/rclone.spec`. Until you restart, any volume related docker commands will timeout trying to access the old socket. Running directly is supported on **Linux only**, not on Windows or MacOS. This is not a problem with managed plugin mode described in details in the [full documentation](https://rclone.org/docker).

The command will create volume mounts under the path given by `--base-dir` (by default `/var/lib/docker-volumes/rclone` available only to root) and maintain the JSON formatted file `docker-plugin.state` in the rclone cache directory with book-keeping records of created and mounted volumes.

All mount and VFS options are submitted by the docker daemon via API, but you can also provide defaults on the command line as well as set path to the config file and cache directory or adjust logging verbosity.

VFS - Virtual File System

This command uses the VFS layer. This adapts the cloud storage objects that rclone uses into something which looks much more like a disk filing system.

Cloud storage objects have lots of properties which aren't like disk files - you can't extend them or write to the middle of them, so the VFS layer has to deal with that. Because there is no one right way of doing this there are various options explained below.

The VFS layer also implements a directory cache - this caches info about files and directories (but not the data) in memory.

VFS Directory Cache

Using the `--dir-cache-time` flag, you can control how long a directory should be considered up to date and not refreshed from the backend. Changes made through the VFS will appear immediately or invalidate the cache.

    --dir-cache-time duration   Time to cache directory entries for (default 5m0s)
    --poll-interval duration    Time to wait between polling for changes. Must be smaller than dir-cache-time. Only on supported remotes. Set to 0 to disable (default 1m0s)

However, changes made directly on the cloud storage by the web interface or a different copy of rclone will only be picked up once the directory cache expires if the backend configured does not support polling for changes. If the backend supports polling, changes will be picked up within the polling interval.

You can send a `SIGHUP` signal to rclone for it to flush all directory caches, regardless of how old they are. Assuming only one rclone instance is running, you can reset the cache like this:

kill -SIGHUP $(pidof rclone)

If you configure rclone with a [remote control](/rc) then you can use rclone rc to flush the whole directory cache:

rclone rc vfs/forget

Or individual files or directories:

rclone rc vfs/forget file=path/to/file dir=path/to/dir

VFS File Buffering

The `--buffer-size` flag determines the amount of memory, that will be used to buffer data in advance.

Each open file will try to keep the specified amount of data in memory at all times. The buffered data is bound to one open file and won't be shared.

This flag is a upper limit for the used memory per open file. The buffer will only use memory for data that is downloaded but not not yet read. If the buffer is empty, only a small amount of memory will be used.

The maximum memory used by rclone for buffering can be up to `--buffer-size * open files`.

VFS File Caching

These flags control the VFS file caching options. File caching is necessary to make the VFS layer appear compatible with a normal file system. It can be disabled at the cost of some compatibility.

For example you'll need to enable VFS caching if you want to read and write simultaneously to a file. See below for more details.

Note that the VFS cache is separate from the cache backend and you may find that you need one or the other or both.

    --cache-dir string                     Directory rclone will use for caching.
    --vfs-cache-mode CacheMode             Cache mode off|minimal|writes|full (default off)
    --vfs-cache-max-age duration           Max time since last access of objects in the cache (default 1h0m0s)
    --vfs-cache-max-size SizeSuffix        Max total size of objects in the cache (default off)
    --vfs-cac