Creating a simple Docker container for Keystone trunk

Big shoutout to Rob Rati, he had some excellent advice and a great blog post that gave me inspiration for this simple example.

Recently I have been doing some work with Swift and Keystone as they relate to the Sahara project. I had been creating virtual machines to host the Keystone and Swift servers because I wanted to gain greater control over running them from Devstack.

After a few rounds of messing with virtual machines through libvirt, I decided to give Docker a try to see if it made the process a tad more light weight. I think it mostly did, but I have not had to do any networking outside of my machine so that might add to my successes.

Here is a small breakdown of the procedure I used on my Fedora 20 machine to install Docker and work through the process of getting a container running with a trunk version of Keystone.

Install Docker

# yum install -y docker-io

Start Docker

# systemctl start docker

Get Fedora images

# docker pull fedora

Create a Dockerfile for Keystone

Build an image from it

# docker build -t testing/keystone - < Dockerfile

Start a container with Keystone running

# docker run -d -p 5000:5000 -p 35357:35357 --name keystone1 testing/keystone

Test(using httpie instead of curl)

$ http localhost:5000
HTTP/1.1 300 Multiple Choices
Content-Length: 753
Content-Type: application/json
Date: Fri, 06 Jun 2014 19:35:05 GMT
Vary: X-Auth-Token

{
    "versions": {
        "values": [
            {
                "id": "v3.0", 
                "links": [
                    {
                        "href": "http://localhost:5000/v3/", 
                        "rel": "self"
                    }
                ], 
                "media-types": [
                    {
                        "base": "application/json", 
                        "type": "application/vnd.openstack.identity-v3+json"
                    }, 
                    {
                        "base": "application/xml", 
                        "type": "application/vnd.openstack.identity-v3+xml"
                    }
                ], 
                "status": "stable", 
                "updated": "2013-03-06T00:00:00Z"
            }, 
            {
                "id": "v2.0", 
                "links": [
                    {
                        "href": "http://localhost:5000/v2.0/", 
                        "rel": "self"
                    }, 
                    {
                        "href": "http://docs.openstack.org/", 
                        "rel": "describedby", 
                    "type": "text/html"
                }
                ], 
                "media-types": [
                    {
                        "base": "application/json", 
                        "type": "application/vnd.openstack.identity-v2.0+json"
                    }, 
                    {
                        "base": "application/xml", 
                        "type": "application/vnd.openstack.identity-v2.0+xml"
                    }
                ], 
                "status": "stable", 
                "updated": "2014-04-17T00:00:00Z"
            }
        ]
    }
}

And presto! a working Keystone instance in a container. At this point it is only configured as a basic server, to get further I will most likely need to attach to the container and setup some users.

All in all a fairly painless process, getting the Dockerfile correct took me the most time but it wasn’t difficult to debug given the way docker outputs to stdout.