CSI NFS

Network File System

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Installation

The plug-in can be installed with the following command:

$ docker plugin install rexray/csi-nfs

Privileges

The plug-in requires the following privileges:

Type	Value
network	host
mount	/dev
allow-all-devices	true
capabilities	CAP_SYS_ADMIN

Configuration

The following environment variables can be used to configure the plug-in:

Environment Variable	Description	Default	Required
X_CSI_NFS_VOLUMES	A list of NFS volume mappings

Examples

To use the csi-nfs plug-in, you must first create a volume using the docker volume create command (unless predefined using X_CSI_NFS_VOLUMES, see Limitations below), specifying both the NFS server host and the exported path:

$ docker volume create -d rexray/csi-nfs -o host=192.168.75.2 -o export=/data test
$ docker volume ls
DRIVER                           VOLUME NAME
rexray/csi-nfs                   test

With the volume created, you can then use it in your containers:

$ docker run -it -v test:/mnt alpine sh
/ # mount | grep nfs
192.168.75.2:/data on /mnt type nfs4 (rw,relatime,vers=4.1,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=10.0.2.15,local_lock=none,addr=192.168.75.2)

Limitations

csi-nfs is an early proof of concept to demonstrate a Docker managed plug-in functioning with CSI. It is not intended to replace Docker's native NFS functionality.

Currently, the plug-in only supports NFSv4, and does not allow for custom options to be passed through to the mount command. In other words, the NFS mount command will always be of the form mount -t nfs {server}:{export} {mountpath}.

When doing a docker volume create command, the csi-nfs plug-in merely creates a reference to an existing NFS volume with the details you have provided. This reference is only persisted across the lifetime of the plug-in, which means if the plug-in is removed and recreated, or upgraded, the volumes previously seen in docker volume ls will disappear. To circumvent this behavior, you can seed the plug-in with the NFS volume definitions using the X_CSI_NFS_VOLUMES env var. For example:

$ docker plugin set rexray/csi-nfs X_CSI_NFS_VOLUMES="vol1=192.168.75.2:/nfsshare vol2=192.168.75.2:/share2"

The env var can be set during plug-in installation, or the plug-in can be disabled, the var set, and then enabled. However, currently only the env var or the persisted volumes from docker volume create can be used, which means if docker volume create is used to define an NFS volume, a later setting of X_CSI_NFS_VOLUMES will be ignored.