Setup Docker Swarm with Ansible.
In this setup I have a client node, which will be my jump box, as it will be used to ssh with the docker user to my swarm nodes with passwordless ssh access.
Hosts file:
$ cat /etc/hosts
10.0.8.2 client
192.168.1.10 swarm-manager
192.168.1.11 swarm-worker-1
192.168.1.12 swarm-worker-2
SSH Config:
$ cat ~/.ssh/config
Host client
Hostname client
User root
IdentityFile /tmp/key.pem
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
Host swarm-manager
Hostname swarm-manager
User root
IdentityFile /tmp/key.pem
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
Host swarm-worker-1
Hostname swarm-worker-1
User root
IdentityFile /tmp/key.pem
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
Host swarm-worker-2
Hostname swarm-worker-2
User root
IdentityFile /tmp/key.pem
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
Install Ansible:
$ apt install python-setuptools -y
$ easy_install pip
$ pip install ansible
Ensure passwordless ssh is working:
$ ansible -i inventory.ini -u root -m ping all
client | SUCCESS => {
"changed": false,
"ping": "pong"
}
swarm-manager | SUCCESS => {
"changed": false,
"ping": "pong"
}
swarm-worker-2 | SUCCESS => {
"changed": false,
"ping": "pong"
}
swarm-worker-1 | SUCCESS => {
"changed": false,
"ping": "pong"
}
$ ansible-playbook -i inventory.ini -u root deploy-swarm.yml
PLAY RECAP
client : ok=11 changed=3 unreachable=0 failed=0
swarm-manager : ok=18 changed=4 unreachable=0 failed=0
swarm-worker-1 : ok=15 changed=1 unreachable=0 failed=0
swarm-worker-2 : ok=15 changed=1 unreachable=0 failed=0
SSH to the Swarm Manager and List the Nodes:
$ docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
0ead0jshzkpyrw7livudrzq9o * swarm-manager Ready Active Leader 18.03.1-ce
iwyp6t3wcjdww0r797kwwkvvy swarm-worker-1 Ready Active 18.03.1-ce
ytcc86ixi0kuuw5mq5xxqamt1 swarm-worker-2 Ready Active 18.03.1-ce
Create a Nginx Demo Service:
$ docker network create --driver overlay appnet
$ docker service create --name nginx --publish 80:80 --network appnet --replicas 6 nginx
$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
k3vwvhmiqbfk nginx replicated 6/6 nginx:latest *:80->80/tcp
$ docker service ps nginx
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
tspsypgis3qe nginx.1 nginx:latest swarm-manager Running Running 34 seconds ago
g2f0ytwb2jjg nginx.2 nginx:latest swarm-worker-1 Running Running 34 seconds ago
clcmew8bcvom nginx.3 nginx:latest swarm-manager Running Running 34 seconds ago
q293r8zwu692 nginx.4 nginx:latest swarm-worker-2 Running Running 34 seconds ago
sv7bqa5e08zw nginx.5 nginx:latest swarm-worker-1 Running Running 34 seconds ago
r7qg9nk0a9o2 nginx.6 nginx:latest swarm-worker-2 Running Running 34 seconds ago
Test the Application:
$ curl -i http://192.168.1.10
HTTP/1.1 200 OK
Server: nginx/1.15.0
Date: Thu, 14 Jun 2018 10:01:34 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 05 Jun 2018 12:00:18 GMT
Connection: keep-alive
ETag: "5b167b52-264"
Accept-Ranges: bytes
$ ansible-playbook -i inventory.ini -u root delete-swarm.yml
PLAY RECAP
swarm-manager : ok=2 changed=1 unreachable=0 failed=0
swarm-worker-1 : ok=2 changed=1 unreachable=0 failed=0
swarm-worker-2 : ok=2 changed=1 unreachable=0 failed=0
Ensure the Nodes is removed from the Swarm, SSH to your Swarm Manager:
$ docker node ls
Error response from daemon: This node is not a swarm manager. Use "docker swarm init" or "docker swarm join" to connect this node to swarm and try again.
Thanks a lot to lucj, make sure to checkout his repo.
