Planet Ceph

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August 24, 2015

Ceph cluster on Docker for testing

{% img center http://sebastien-han.fr/images/ceph-docker-demo.jpg Ceph cluster on Docker for testing %}

I haven’t advertised this one really much (even if I’ve been using it in some articles).
Since people are still wondering how to quickly get a full Ceph cluster up and running for testing, I believe it deserves its own article so it will get more visibility.
Re-introducing the Ceph demo container.
This is going to be a really short article :).

It is fairly easy to get up and running. Obviously you need to have Docker installed.
Since we will be using --net=host option to directly plug the daemons on the host interface, you will need to select the IP address.

$ ip -4 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    inet 192.168.0.69/24 brd 192.168.0.255 scope global dynamic eth0
       valid_lft 97sec preferred_lft 97sec
3: docker0@NONE: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    inet 172.17.42.1/16 scope global docker0
       valid_lft forever preferred_lft forever

For me, this going to be 192.168.0.69.
Now let’s run the container:

$ sudo docker run -d --net=host -v /etc/ceph:/etc/ceph -e MON_IP=192.168.0.69 -e CEPH_NETWORK=192.168.0.0/24 ceph/demo
d3e4ead6c0ba4606201f9f861bd960f4c6d9376d6686714664489540b2843ce0

Check that the container is up and running:

$ sudo docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
098fa6c045f2        ceph/demo:latest    "/entrypoint.sh"    5 seconds ago       Up 3 seconds                            desperate_yonath

$ sudo docker exec 098fa6c045f2 ceph -s
    cluster d6b3670d-5cb1-4280-bb09-78ffc40afed1
     health HEALTH_OK
     monmap e1: 1 mons at {atomic1=192.168.0.69:6789/0}
            election epoch 2, quorum 0 atomic1
     mdsmap e5: 1/1/1 up {0=0=up:active}
     osdmap e16: 1 osds: 1 up, 1 in
      pgmap v19: 120 pgs, 8 pools, 2810 bytes data, 63 objects
            7081 MB used, 4124 MB / 11206 MB avail
                 120 active+clean
  client io 11271 B/s rd, 1056 B/s wr, 30 op/s

Thanks to this container you will get all the Ceph daemons up and running:

  • 1 monitor
  • 1 object storage daemon
  • 1 metadata server
  • 1 rados gateway

All the ports will automatically get exposed, so you can access all the services really easily.

It looks like you do not have any more excuses now to try out Ceph :-).

Careers