dvdcli

dvdcli

dvdcli is a Docker Volume Driver client CLI. The CLI is used enable any application to call the CLI to perform external Volume Management to a Linux host. This project exposes the Docker Volume Driver eco-system for additional use cases.

Docker Volume Plugins

As of Docker 1.7, there was a Volume Driver API defined that allows Docker to work with external storage providers. The API documentation is available here. As of Docker 1.11.0, the API has seven main features, Create, Remove, Mount, Unmount, Path, List, Get. In order to leverage these features, a Volume Driver is created that manages and orchestrates the API calls to specific storage platforms. It is these Volume Drivers that this project is using in order to enable Volume Management. See official plugins here.

Volume Plugin Compatibility

In order to use dvdcli 0.2.0 or above your Volume Plugin must be able to perform a Get() operation. This functionality only came about with Docker 1.10 so please make sure the plugin that dvdcli is interfacing with has this capability.

Note: This does not mean that Docker is required for dvdcli to function. dvdcli currently shares the Docker Engine 1.11.0 functionality for requesting volumes and talking with volume plugins so the compatibility of dvdcli tracks the specified Docker Engine version. If your plugin supports the necessary Docker Engine version then it will work with dvdcli.

Installation

Installing dvdcli couldn't be easier. The sh - portion can be replaced with sh -s unstable, or sh -s staged as well.

curl -sSL https://dl.bintray.com/emccode/dvdcli/install | sh -s stable

Downloading

There are also pre-built binaries at the following locations:

Repository	Version	Description
unstable		The most up-to-date, bleeding-edge, and often unstable dvdcli binaries.
staged		The most up-to-date, release candidate dvdcli binaries.
stable		The most up-to-date, stable dvdcli binaries.

CLI

The CLI takes advantage of native Docker packages which means the functionality available from the CLI mimics what the Docker daemon does to manage Volumes. In addition, the SPEC relating to how the API communicates, ie looking up socket files or HTTP endpoints, is respected entirely.

A typical command from Docker to take advantages of Volume Drivers would be something like docker run -ti --volume-driver=rexray -v volume:/to busybox.

For dvdcli, the command is very similar. dvdcli mount --volumedriver=rexray --volumename=test. The main difference is that in Docker's case the mount path is specified as a target inside of a container. dvdcli leaves the mount at the host level, and it is then up to the consumer to make the path available in whatever way necessary.

Examples

Mount a volume

If you would like to ensure a mount operation is interpreted solely as a mount the --explicitCreate=true flag can be specified.

dvdcli mount --explicitCreate --volumedriver=rexray --volumename=test123456789

It is possible to issue a mount command which would create a volume if it does not exist as well as mount the volume. This is the default behavior.

dvdcli mount --volumedriver=rexray --volumename=test123456789

Implicit with Options

It is also possible to create implicitly and also specify options for the volume that is created.

dvdcli mount --volumedriver=rexray --volumename=test123456789  \
  --volumeopts=size=5 --volumeopts=iops=150 --volumeopts=volumetype=io1 \
  --volumeopts=newFsType=ext4 --volumeopts=overwritefs=true

Unmount a volume

dvdcli unmount --volumedriver=rexray --volumename=test

Create a volume

dvdcli create --volumedriver=rexray --volumename=test123456789 \
  --volumeopts=size=5 --volumeopts=iops=150 --volumeopts=volumetype=io1 \
  --volumeopts=newFsType=ext4 --volumeopts=overwritefs=true

Remove a volume

dvdcli remove --volumedriver=rexray --volumename=test

Return path of a mounted volume

dvdcli path --volumedriver=rexray --volumename=test

List availabile volumes

dvdcli list --volumedriver=rexray

Get a specific volume or check whether exists or not

dvdcli get --volumedriver=rexray --volumename=test

Extra Options

These options are specific to the interpretation of the Volume Driver that you are invoking. For REX-Ray these would be valid options.

EMC {code} - REX-Ray

The REX-Ray project is a good example of a service that can expose a valid Volume Driver endpoint that can be used and is available here. The options mentioned above are dependent on the Volume Driver. REX-Ray does implement options as listed above.

Licensing

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Support

Please file bugs and issues on the Github issues page for this project. This is to help keep track and document everything related to this repo. For general discussions and further support you can join the EMC {code} Community slack channel. Lastly, for questions asked on Stackoverflow.com please tag them with EMC. The code and documentation are released with no warranties or SLAs and are intended to be supported through a community driven process.