Docker1.12 on AWS : 10 command(ment)s to manage Swarm cluster

Atharva Chauthaiwale 5:02 AM No comments

Introduction


 In July 2016,  Docker Inc. released 1.12 version with many great features including Swarm Mode ( built-in orchestration ).  Latest Swarm Mode along with docker-machine tool greatly simplifies the the job of creating/managing a cluster of docker containers on different cloud providers.   In this blog post, I am going to explain how to create/manage a 3 node Swarm Cluster on AWS using docker-machine.
Note :  These steps are only applicable to docker 1.12 and above !

Pre-requisite Steps

a]  Install docker-machine on your Linux machine or Mac. 
b] Create AWS account ( If don't have already ) and configure AWS credentials for docker machine. See details here.
c] In AWS EC2 console, create a security group called "docker-machine".  Add following inbound policies to the security group. Following ports are required for swarm cluster communication. See this video for the details


Once we have all the requisites in place, we are ready to deploy Swarm cluster on AWS using our 10 command (ment )s.

 1. You  shall  use 'docker-machine create' to bring up new VMs 

 This command creates EC2 instance and installs docker 1.12 on it.

docker-machine create --driver amazonec2  swarm-manager

docker-machine create --driver amazonec2  swarm-worker-1

docker-machine create --driver amazonec2  swarm-worker-2

 Verify the status of the machines using 


docker-machine ls 

2.  You shall use 'docker swarm init' to configure Swarm manager

This command initializes Swarm manager on the VM.  To use this, first get IP address of swarm manager machine followed by swarm init command. 
MANAGER_IP=`docker-machine inspect --format '{{ .Driver.PrivateIPAddress}}' swarm-manager`
docker-machine ssh swarm-manager sudo docker swarm init --advertise-addr "$MANAGER_IP":2377

3. You shall use 'docker swarm join' to configure Swarm workers.

 Swarm worker nodes (worker-1, worker-2) can join swarm cluster using this command. 
First get the token from swarm manager. 
TOKEN=`docker-machine ssh swarm-manager sudo docker swarm join-token -q worker`

 Join worker-1 


docker-machine ssh swarm-worker-1 sudo docker swarm join --token "$TOKEN" "$MANAGER_IP":2377


Join worker-2

docker-machine ssh swarm-worker-2 sudo docker swarm join --token "$TOKEN" "$MANAGER_IP":2377


4. You shall use 'node ls' & 'node inspect' to verify status of Swarm cluster


Get status of Swarm cluster by running this command on Swarm Manager.

docker-machine ssh swarm-manager sudo docker node ls

User Inspect command to  get status of both manager and worker. 

docker-machine ssh swarm-manager sudo docker node inspect swarm-worker-1

docker-machine ssh swarm-manager sudo docker node inspect swarm-manager

5. You shall use 'docker service create'  to deploy service on Swarm cluster


Service create command deploys one more containers on the Swarm cluster. 

   docker-machine ssh swarm-manager sudo docker service create --name myredis --replicas=1 redis:3.0.6
6. You shall use 'service ps' and 'service inspect' to verify status of deployed service
docker-machine ssh swarm-manager sudo docker service ps myredis 

docker-machine ssh swarm-manager sudo docker service inspect myredis

7. You shall use 'docker service scale' to scale up/down the service
docker-machine ssh swarm-manager sudo docker service scale myredis=2

8. You shall use 'docker service update' for rolling updates 

E.g. update redis image to version 3.0.7. 
docker-machine ssh swarm-manager sudo docker service update --image redis:3.0.7 myredis

 9. You shall use 'docker service rm' to undeploy service
docker-machine ssh swarm-manager sudo docker service rm myredis

 10. You shall use 'docker-machine stop' and 'docker-machine rm' to delete VMs

 Stop/Delete EC2 instances using stop and rm command.


docker-machine stop swarm-worker-1
docker-machine stop swarm-worker-2
docker-machine stop swarm-manager

docker-machine rm swarm-worker-1
docker-machine rm swarm-worker-2
docker-machine rm swarm-manager


References:

1. Docker Swarm Mode :  https://docs.docker.com/engine/swarm/
2. Docker machine : https://github.com/docker/machine

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