Docker Swarm & Flocker Driver Integration

Docker Swarm and Flocker are evolving technologies & I was trying to integrate them but there was some lack of documentation efforts & really its challenge to integrate these two technologies. After putting lots of integration efforts I came up with useful configuration steps.

First of all, letâ€™s check the background of these technologies – Docker Swarm is the cluster management tool for the Docker containers. Docker Swarm provides native clustering capabilities to turn a group of Docker engines into a single node.

Flocker is an open-source container data volume manager for your Dockerized applications. Flocker manages Docker containers and data volumes together. Flocker allows you to use external persistent storage and move it between containers using Docker Swarm.

Docker Swarm & Flocker Driver integration Steps

1. Check Status Flocker Node list

root@flockerdev1-virtual-machine:/home/flocker-dev1# flockerctl list-nodes
SERVERÂ Â Â Â  ADDRESS
 
53bbc30eÂ Â  172.17.58.212
 
295aabcdÂ Â  172.17.58.211
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

2. Check Flocker Volume list

root@flockerdev1-virtual-machine:/home/flocker-dev1# flockerctl ls

DATASETÂ Â  SIZEÂ Â  METADATAÂ Â  STATUSÂ Â  SERVER
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

3. Create a Flocker Volume

root@flockerdev1-virtual-machine:/home/flocker-dev1# docker volume create --driver flocker --name yp-pune -o size=1GB

yp-pune
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

4. Now again Check Flocker Volume list

root@flockerdev1-virtual-machine:/home/flocker-dev1# flockerctl ls

/usr/local/bin/flockerctl: 3: read: Illegal option -d
 
DATASETÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  SIZEÂ Â Â  METADATAÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  STATUSÂ Â Â Â Â Â Â Â  SERVER
 
938e66cf-95ef-4131-9c3a-52c0fe5236e5Â Â  1.00GÂ Â  maximum_size=1073741824,name=yp-puneÂ Â  attached âœ…Â Â  295aabcd (172.17.58.211)
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

5. Check the Swarm Cluster Node status

root@flockerdev1-virtual-machine:/home/flocker-dev1# sudo docker node list

IDÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  HOSTNAMEÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  STATUSÂ  AVAILABILITYÂ  MANAGER STATUS
 
3c4w4zvcyzmwhrr0mrxfkc5pf *Â  flockerdev1-virtual-machineÂ  ReadyÂ Â  ActiveÂ Â Â Â Â Â Â  Leader
 
4j8ir0rya0x3nh068xxbct4z6Â Â Â  flockerdev2-virtual-machineÂ  ReadyÂ Â  Active
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

6. Now create a Swarm Service

root@flockerdev1-virtual-machine:/home/flocker-dev1# docker service create --mount type=volume,source=yp-pune,target=/Calsoft --name yogesh centos sh -c 'while true; do touch /Calsoft/$(hostname)-$(date +%F-%T); sleep 5; done'

0pdnne9urig6kp23130hrp285
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

7. Check status of Swarm Service

root@flockerdev1-virtual-machine:/home/flocker-dev1# sudo docker service ls

IDÂ Â Â Â Â Â Â Â Â Â Â  NAMEÂ Â Â  REPLICASÂ  IMAGEÂ Â  COMMAND
 
0pdnne9urig6Â  yogeshÂ  1/1Â Â Â Â Â Â  centosÂ  sh -c while true; do touch /Calsoft/$(hostname)-$(date +%F-%T); sleep 5; done
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

8. Find out on which node service is running

root@flockerdev1-virtual-machine:/home/flocker-dev1# sudo docker service ps yogesh

IDÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  NAMEÂ Â Â Â Â  IMAGEÂ Â  NODEÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  DESIRED STATEÂ  CURRENT STATEÂ Â Â Â Â Â Â Â Â Â Â Â Â Â  ERROR
 
1nowf2k2zmjv79zkdk9m3ewh6Â  yogesh.1Â  centosÂ  flockerdev1-virtual-machineÂ  RunningÂ Â Â Â Â Â Â  Running about a minute ago
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

9. Check the IO on the Flocker volume

root@flockerdev1-virtual-machine:/home/flocker-dev1# ls /flocker/938e66cf-95ef-4131-9c3a-52c0fe5236e5

c8e89ca73b93-2016-09-22-09:59:53Â  c8e89ca73b93-2016-09-22-10:00:38Â  c8e89ca73b93-2016-09-22-10:01:24Â  c8e89ca73b93-2016-09-22-10:02:09
 
c8e89ca73b93-2016-09-22-09:59:58Â  c8e89ca73b93-2016-09-22-10:00:43Â  c8e89ca73b93-2016-09-22-10:01:29Â  c8e89ca73b93-2016-09-22-10:02:14
 
c8e89ca73b93-2016-09-22-10:00:08Â  c8e89ca73b93-2016-09-22-10:00:54Â  c8e89ca73b93-2016-09-22-10:01:39
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

10. Now trigger the failure on the active Swarm Node

root@flockerdev1-virtual-machine:/home/flocker-dev1# sudo docker node update --availability drain flockerdev1-virtual-machine

flockerdev1-virtual-machine
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

11. Now Check the Swarm Node status

root@flockerdev1-virtual-machine:/home/flocker-dev1# sudo docker node list

IDÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  HOSTNAMEÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  STATUSÂ  AVAILABILITYÂ  MANAGER STATUS
 
3c4w4zvcyzmwhrr0mrxfkc5pf *Â  flockerdev1-virtual-machineÂ  ReadyÂ Â  DrainÂ Â Â Â Â Â Â Â  Leader
 
4j8ir0rya0x3nh068xxbct4z6Â Â Â  flockerdev2-virtual-machineÂ  ReadyÂ Â  Active
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

12. Now Check the Swarm Service Status

root@flockerdev1-virtual-machine:/home/flocker-dev1# sudo docker service ps yogesh

IDÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  NAMEÂ Â Â Â Â Â Â Â Â  IMAGEÂ Â  NODEÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  DESIRED STATEÂ  CURRENT STATEÂ Â Â Â Â Â Â Â Â Â Â  ERROR
 
0kb2mmgmzvmiqyx2krigo2j09Â  yogesh.1Â Â Â Â Â  centosÂ  flockerdev2-virtual-machineÂ  RunningÂ Â Â Â Â  Â Â Starting 52 seconds ago
 
1nowf2k2zmjv79zkdk9m3ewh6Â Â  \_ yogesh.1Â  centosÂ  flockerdev1-virtual-machineÂ  ShutdownÂ Â Â Â Â Â  Shutdown 55 seconds ago
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

14. Now Check the volume status in flockerctl [Volume & Containers are automatically migrated to other active node]

root@flockerdev1-virtual-machine:/home/flocker-dev1# flockerctl ls

/usr/local/bin/flockerctl: 3: read: Illegal option -d
 
DATASETÂ Â Â Â Â Â Â Â Â Â Â Â Â  Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â SIZEÂ Â Â  METADATAÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  STATUSÂ Â Â Â Â Â Â Â  SERVER
 
938e66cf-95ef-4131-9c3a-52c0fe5236e5Â Â  1.00GÂ Â  maximum_size=1073741824,name=yp-puneÂ Â  attached âœ…Â Â  53bbc30e (172.17.58.212)
 
root@flockerdev1-virtual-machine:/home/flocker-dev1#

15. Now Check IO on the Flocker volume [IO is continued from the other active node on the same Flocker volume]

root@flockerdev2-virtual-machine:/home/flocker-dev1# ls /flocker/938e66cf-95ef-4131-9c3a-52c0fe5236e5

c8e89ca73b93-2016-09-22-09:59:53Â  c8e89ca73b93-2016-09-22-10:00:38Â  c8e89ca73b93-2016-09-22-10:01:24Â  c8e89ca73b93-2016-09-22-10:02:09
 
c8e89ca73b93-2016-09-22-09:59:58Â  c8e89ca73b93-2016-09-22-10:00:43Â  c8e89ca73b93-2016-09-22-10:01:29Â  c8e89ca73b93-2016-09-22-10:02:14
 
5cc6b2b33d59-2016-09-22-10:10:10Â  c8e89ca73b93-2016-09-22-10:00:23Â  c8e89ca73b93-2016-09-22-10:01:44Â  c8e89ca73b93-2016-09-22-10:03:04
 
5cc6b2b33d59-2016-09-22-10:10:19Â  c8e89ca73b93-2016-09-22-10:00:28Â  c8e89ca73b93-2016-09-22-10:01:49Â  c8e89ca73b93-2016-09-22-10:03:09

Using these steps we can easily access Flocker Volumes in the Swarm Docker Cluster. Hope this document will helps you.

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