06 - Docker Swarm - Container Orchestration

 Docker Swarm - Container Orchestration

• Create Cluster
• Build & Deployment automated
• Rolling Deployment
• Update Version

• Docker Swarm is clustering for Docker
• It turns several Docker hosts into a single virtual Docker host
• The Swarm is controlled by Swarm Manager
• Each Docker code communicates with the manager
• It can be installed manually or by using Docker Machine

• Scheduler
• Service Discover
• Consul -> provide DNS
• Zookeeper - configuration management tools

Cheat Sheet => https://lzone.de/cheat-sheet/Docker%20Swarm

LAB

mkdir DockerSwarm

cd DockerSwarm

mkdir manager vm1 vm2 

*** Manager Node ****

cd manager

vagrant ssh

sudo su -

hostnamectrl set-hostname managernode.unix.in

bash

vi /etc/hosts

192.168.33.14 managernode.unix.in

192.168.33.15 workernode1.unix.in

192.168.33.16 workernode1.unix.in

## Install Docker C

curl -fsSL get.docker.com | sh

## Add user Vagrant in Docker group

sudo usermod -aG docker vagrant

id vagrant

## Start Docker Service

systemctl start docker

systemctl enable docker

## Initialize docker swarm cluster - Become Manager node

docker swarm init --advertise-addr 192.168.33.14

## save token after initialized in token.txt

docker swarm join --token xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 192.168.33.14:2377

docker node ls

** 1 *** Go to nodes and run "docker swarm join xxx"

## create service

docker service create --replicas 1 --name helloworld alpin ping docker.com

docker service ls

docker service inspect --pretty helloworld

docker ps

docker service ps helloworld

# Scale service in Nodes for high availability

docker service scale helloworld=2

docker ps

docker service scale helloworld=3

docker ps

# Perform Rolling deployment 

# create 3 redis container

docker service create --replicas 3 --name redis redis:3.0.6

docker service inspect --preety redis

docker service ps redis

=> Now Update my servie 

docker service update --image redis:3.0.7 redis

=> you monitoring updating redis service

docker service ps redis

# Stop one container - Docker swarm dedected and start again

docker stop <container>

docker ps

*** Worker Node 1 ****

cd vm1

vagrant ssh

sudo su -

hostnamectrl set-hostname workernode1.unix.in

bash

vi /etc/hosts

192.168.33.14 managernode.unix.in

192.168.33.15 workernode1.unix.in

192.168.33.16 workernode1.unix.in

curl -fsSL get.docker.com | sh

sudo usermod -aG docker vagrant

id vagrant

systemctl start docker

systemctl enable docker

*** 1 ***

docker swarm join --token xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 192.168.33.14:2377

This node joined a swarm as a worker

*** Worker Node 2 ****

cd vm2

vagrant ssh

sudo su -

hostnamectrl set-hostname workernode2.unix.in

bash

vi /etc/hosts

192.168.33.14 managernode.unix.in

192.168.33.15 workernode1.unix.in

192.168.33.16 workernode1.unix.in

curl -fsSL get.docker.com | sh

sudo usermod -aG docker vagrant

id vagrant

systemctl start docker

systemctl enable docker

*** 1 ***

docker swarm join --token xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 192.168.33.14:2377

This node joined a swarm as a worker