openstorage

README

Current Build Status

About Open Storage

OpenStorage is a clustered implementation of the Open Storage specification and relies on the Docker runtime. It allows you to run stateful services in Docker in a multi-host environment. It plugs into Docker volumes to provide storage to a container and plugs into Swarm to operate in a clustered environment.

What you get from using Open Storage

When you install openstorage on a Linux host, you will automatically get a stateful storage layer that integrates with the Docker runtime and operates in a multi host environment. It starts an Open Storage Daemon - OSD that currently supports Docker and will support any Linux container runtime that conforms to the OCI.

Scheduler integration

OSD will work with any distributed scheduler that is compatible with the Docker remote API.

Docker Volumes

OSD integrates with Docker Volumes and provisions storage to a container on behalf of any third party OSD driver and ensures the volumes are available in a multi host environment.

Graph Driver

OpenStorage provides support for the Graph Driver in addition to Docker Volumes. When used as a graph driver, the container's layers will be stored on a volume provided by the OSD.

An example usage

The diagram below shows OSD integrated with Docker and Swarm to allow for provisioning of storage to containers in a multi node environment.

There are default drivers built-in for NFS, AWS and BTRFS. By using openstorage, you can get container granular, stateful storage provisioning to Linux containers with the backends supported by openstorage. We are working with the storage ecosystem to add more drivers for various storage providers.

Providers that support a multi-node environment, such as AWS or NFS to name a few, can provide highly available storage to linux containers across multiple hosts.

Installing Dependencies

libopenstorage is written in the Go programming language. If you haven't set up a Go development environment, please follow these instructions to install golang and set up GOPATH. Your version of Go must be at least 1.5 - we use the golang 1.5 vendor experiment https://golang.org/s/go15vendor. Note that the version of Go in package repositories of some operating systems is outdated, so please download the latest version.

After setting up Go, you should be able to go get libopenstorage as expected (we use -d to only download):

$ GO15VENDOREXPERIMENT=1 go get -d github.com/libopenstorage/openstorage/...

Building from Source

At this point you can build openstorage from the source folder:

$ cd $GOPATH/src/github.com/libopenstorage/openstorage 
$ make install

or run only unit tests:

$ cd $GOPATH/src/github.com/libopenstorage/openstorage 
$ make test

Starting OSD

OSD is both the openstorage daemon and the CLI. When run as a daemon, the OSD is ready to receive RESTful commands to operate on volumes and attach them to a Docker container. It works with the Docker volumes plugin interface will communicate with Docker version 1.7 and later. When this daemon is running, Docker will automatically commincate with the daemon to manage a container's volumes.

To start the OSD in daemon mode:

osd -d -f etc/config/config.yaml

where, config.yaml is the daemon's configuiration file and it's format is explained below.

To use the OSD cli, see the CLI help menu:

NAME:
   osd - Open Storage CLI

USAGE:
   osd [global options] command [command options] [arguments...]

VERSION:
   0.3

COMMANDS:
   driver, d    Manage drivers
   aws, v       Manage aws volumes
   nfs, v       Manage nfs volumes
   help, h      Shows a list of commands or help for one command
   
GLOBAL OPTIONS:
   --json, -j                                   output in json
   --daemon, -d                                 Start OSD in daemon mode
   --driver [--driver option --driver option]   driver name and options: name=btrfs,root_vol=/var/openstorage/btrfs
   --file, -f                                   file to read the OSD configuration from.
   --help, -h                                   show help
   --version, -v                                print the version

OSD config file

The OSD daemon loads a YAML configuration file that tells the daemon what drivers to load and the driver specific attributes. Here is an example of config.yaml:

osd:
  drivers:
      nfs:
        server: "171.30.0.20"
        path: "/nfs"
      btrfs:
      aws:
        aws_access_key_id: your_aws_access_key_id
        aws_secret_access_key: your_aws_secret_access_key
      coprhd:
	restUrl: coprhd_rest_url
	user: rest_user_name
	password: rest_user_password
	consistency_group: consistency_group_id
        project: project_id
	varray: varray_id
	vpool: vpool_id
	
  graphdrivers:
     proxy:
     layer0:

The above example initializes the OSD with three drivers: NFS, BTRFS and AWS. Each have their own configuration sections.

Adding your volume driver

Adding a driver is fairly straightforward:

1. Add your driver decleration in volumes/drivers.go

2. Add your driver mydriver implementation in the volumes/drivers/mydriver directory. The driver must implement the VolumeDriver interface specified in volumes/volume.go. This interface is an implementation of the specification available [here] (http://api.openstorage.org/).

3. You're driver must be a File Volume driver or a Block Volume driver. A File Volume driver will not implement a few low level primatives, such as Format, Attach and Detach.

Here is an example of drivers.go:

// To add a provider to openstorage, declare the provider here.
package drivers

import (
    "github.com/libopenstorage/openstorage/volume/drivers/aws"
    "github.com/libopenstorage/openstorage/volume/drivers/btrfs"
    "github.com/libopenstorage/openstorage/volume/drivers/nfs"
    "github.com/libopenstorage/openstorage/volume"
)           
            
type Driver struct {
    providerType volume.ProviderType
    name         string
}       
            
var (       
    providers = []Driver{
        // AWS provider. This provisions storage from EBS.
        {providerType: volume.Block,
            name: aws.Name},
        // NFS provider. This provisions storage from an NFS server.
        {providerType: volume.File,
            name: nfs.Name},
        // BTRFS provider. This provisions storage from local btrfs fs.
        {providerType: volume.File,
            name: btrfs.Name},
    }
)

That's pretty much it. At this point, when you start the OSD, your driver will be loaded.

Testing

make test # test on your local machine
make docker-test # test within a docker container

Assuming you are using the NFS driver, to create a volume with a default size of 1GB and attach it to a Docker container, you can do the following

$ docker volume create -d nfs
9ccb7280-918b-464f-8a34-34e73e9214d2
$ docker run -v 9ccb7280-918b-464f-8a34-34e73e9214d2:/root --volume-driver=nfs -ti busybox

Updating to latest Source

To update the source folder and all dependencies:

$GOPATH/src/github.com/libopenstorage/openstorage $ make update-test-deps

However note that all dependencies are vendored in the vendor directory, so this is not necessary in general as long as you have GO15VENDOREXPERIMENT set:

export GO15VENDOREXPERIMENT=1

Building a Docker image

OSD can run inside of Docker:

make docker-build-osd

This builds a Docker image called openstorage/osd. You can then run the image:

make launch

OSD on the Docker registry

Pre-built Docker images of the OSD are available at https://hub.docker.com/r/openstorage/osd/

Using openstorage with systemd

[Unit]
Description=Open Storage

[Service]
CPUQuota=200%
MemoryLimit=1536M
ExecStart=/usr/local/bin/osd
Restart=on-failure

[Install]
WantedBy=multi-user.target

Contributing

The specification and code is licensed under the Apache 2.0 license found in the LICENSE file of this repository.

Sign your work

The sign-off is a simple line at the end of the explanation for the patch, which certifies that you wrote it or otherwise have the right to pass it on as an open-source patch. The rules are pretty simple: if you can certify the below (from developercertificate.org):

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
660 York Street, Suite 102,
San Francisco, CA 94110 USA

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.


Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified
    it.

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

then you just add a line to every git commit message:

Signed-off-by: Joe Smith <joe@gmail.com>

using your real name (sorry, no pseudonyms or anonymous contributions.)

You can add the sign off when creating the git commit via git commit -s.