docker-swarm

docker node inspect self --pretty

Intro to DockerSwarm Setup the cluster using the Vagrant and initialised the swarm

To see how to connect your Docker Client to the Docker Engine running on this virtual machine, run: docker-machine env master01
 gopinathjayabalan@IND-CHN-gopinath  ~/code  docker-machine env master01
export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://192.168.99.100:2376"
export DOCKER_CERT_PATH="/Users/gopinathjayabalan/.docker/machine/machines/master01"
export DOCKER_MACHINE_NAME="master01"
# Run this command to configure your shell:
# eval $(docker-machine env master01)
 gopinathjayabalan@IND-CHN-gopinath  ~/code  eval $(docker-machine env master01)
 gopinathjayabalan@IND-CHN-gopinath  ~/code 

Connect to swarm master - Docker-Machine environment

docker-machine ssh master01

Initialize Docker Swarm master

docker swarm init --advertise-addr 192.168.99.100

#####Dockerfile

#EXAMPLE-1
#simple web server
FROM centos:latest

LABEL maintainer="Sri/Gopi"

RUN yum install -y httpd

RUN echo "Our Container Website >> /var/www/html/index.html"

EXPOSE 80

ENTRYPOINT apachectl -DFOREGROUND

#######To build image using dockerfile

docker build -t <image-name> -f dockerfile .

docker ps

docker exec -it <container-name> sh

ls

#####Docker-compose file Demo-01 ######note: Run this compose file where the Dockerfile need to be present.

version: "3"

services:
  webapi:
    image: sixeyed/password-web:v1
    ports:
      - "81:80"
    environment:
      - PasswordApi:Url=http://password-api:5001
    deploy:
      replicas: 2
  password-api:
    image: sixeyed/password-api:v1
    deploy:
      replicas: 4

Start the Docker-compose

docker compose up

docker compose down

docker ps

#######To set up the docker swarm

docker-machine create --driver virtualbox master01
docker-machine create --driver virtualbox worker01
docker-machine create --driver virtualbox worker02
docker-machine create --driver virtualbox worker03

To setup the environment variables

docker-machine ssh master01

docker-machine ssh worker01

docker-machine ssh worker02

docker-machine ssh worker03

####### Initialize Docker Swarm master

docker swarm init --advertise-addr 192.168.99.100

Get the swarm token from the master

docker swarm join-token worker

Put the token generated in the worker

Create a network in the master

docker network create -d overlay  development

docker network ls

Create a secret in the master

printf "test" | docker secret create dev_env_appdb01 -

docker secret ls

Create a config in the master

docker config create dev-config config.js 

docker config ls

Start the Docker-stack using the same compose file

docker stack deploy -c 01-db-demo.yml development

docker stack deploy -c 02-ui-demo.yml development

docker stack deploy -c 01-api-demo.yml development

docker stack ls

docker service ls

docker service ps <service-id>

docker ps

docker exec -it <container-id> bash

Ping from api container

ping api

To show the output in browser

192.168.99.100:8080

Stack File Demo-02

version: "3"

services:
  webapi:
    image: sixeyed/password-web:v1
    ports:
      - "81:80"
    environment:
      - PasswordApi:Url=http://password-api:5001
    deploy:
      replicas: 5
  password-api:
    image: sixeyed/password-api:v1
    deploy:
      replicas: 10

######Stack File Demo-03

version: "3.5"

services:
  webapi:
    image: sixeyed/password-web:v1
    ports:
      - "81:80"
    environment:
      - PasswordApi:Url=http://password-api:5001
    deploy:
      replicas: 2
  password-api:
    image: sixeyed/password-api:v2
    deploy:
      replicas: 3

######Command EXAMPLES

docker service update --publish-add 8080:80 <service-name>

update the service and see the output progress in console

docker service update --detach=false replicas=3

CPU and Memory limit - soft and hard limit

NOTE: Applying the CPU and Memory limit restart.

docker service update --limit-cpu=.5 --reserve-cpu=.5 --limit-memory=64m --reserve-memory=128m --detach=true service-name

There are a couple of ways to handle scaling in a running service.

Replicas:

######Docker scale up only on replicated mode Global and Replicated

docker service create --name myserice -p 8080:80 --mode global --detach=false nginx

docker service create --name testweb -p 8080:80 httpd

update the replicas for service in single command. "In docker update replica=3 service1 service2" its not possible

Hence use docker scale command

docker service scale --detach=false service-1=3 service-2=5

Node Constraints

docker service creat --name name-given-node-constraints -p 8080:80 --constraint 'node.labels.mynode == testnode' --replica 5 httpd

Troubleshoot: Active Internet connections Active UNIX domain sockets

netstat tulp

READ THIS FOR REFERENCE

https://medium.com/devopsion/solving-the-routing-mess-for-services-in-docker-73492c37b335

https://upcloud.com/community/tutorials/docker-swarm-orchestration/

Docker Documentation

https://docs.docker.com/v17.09/develop/
SWARM Service
https://docs.docker.com/v17.09/get-started/part4/#restarting-docker-machines
Simple Python App TO get the container ID
https://docs.docker.com/v17.09/get-started/part2/#run-the-app

ENSURE If we you created in Replica mode.. Can you change to Global ? and Viseversa

######personal reference Remove Later From here

#Example App NodeJs to deploy in Docker Swarm
https://github.com/docker/labs/tree/master/developer-tools/nodejs/porting/

#Best Refer for 12 factor
https://github.com/docker/labs/tree/master/12factor

#Docker Compose Refer
https://docs.docker.com/compose/samples-for-compose/

#Voting App
https://github.com/dockersamples/example-voting-app

#NodeJs Docker Webapp
https://nodejs.org/de/docs/guides/nodejs-docker-webapp/

Best full Stack App Refer
https://medium.com/@carminezaccagnino/top-4-cool-projects-to-build-to-enrich-your-full-stack-web-development-skills-8cbdd3673f43

saigopi/docker-swarm