etsisi-ccforiot / assignment1

Vagrant and Docker Assignment

Assignment 1

Vagrant and Docker task

2020-2021

INTERNET OF THINGS MASTER DEGREE

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Requirements summary

• MacOS, Windows and Linux (Recommended)
  • Install Virtual Box and Vagrant
  • Use Docker Playground for Docker to avoid Windows world (Hyper-V, WSL, etc...)
  • Registration in Docker Hub

MacOS and Linux users can install Docker with no problems, but Docker Playground is fine enough.

All needed file could be download from Moodle or via GitHub

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Vagrant assignment

Assignment 1 (Part I)

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Software Requirements

• Virtual Box
• Vagrant
  • for Windows
    • disable Hyper-V
  • for Mac
  • for Linux

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• Initialize a directory for usage with Vagrant

vagrant init

• Store the box hashicorp/precise64

vagrant box add hashicorp/precise64

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• Edit the vagrant file

Vagrant.configure("2") do |config|
  config.vm.box = " hashicorp/precise64"
  config.vm.provision :shell, path: "bootstrap.sh"
end

• Edit the bootstrap.sh file (create it if needed)

#!/usr/bin/env bash
apt-get update
apt-get install -y apache2
if ! [ -L /var/www ]; then
    rm -rf /var/www
    ln -fs /vagrant /var/www
fi

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• Start the virtual machine

vagrant up

• SSH into guest machine

vagrant ssh

• Run the following command in the guest machine

vagrant@precise64:~$ wget -qO- 127.0.0.1

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• Modifiy the Vagrantfile

Vagrant.configure("2") do |config|
  config.vm.box = "hashicorp/precise64"
  config.vm.provision :shell, path: "bootstrap.sh"
  config.vm.network :forwarded_port, guest: 80, host: 4567
end

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• Run a vagrant reload or vagrant up so that these changes can take effect.
• Once the machine is running again, load http://127.0.0.1:4567 in the browser of your host machine.

You should see a web page that is being served from the virtual machine that was automatically setup by Vagrant

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Docker assignment

Assignment 1 (Part II)

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Software Requirements

• Docker Playground (Recommended -- via web browser)
• Docker Desktop
  • for Windows
    • enable WSL 2 (Recommended)
    • or enable Hyper-V
  • for Mac
  • for Linux

Account in Docker is required!

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Part I: Docker Images

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• Define a container with Dockerfile (file Dockerfile)

# Use an official Python runtime as a parent image
FROM python:2.7-slim

# Set the working directory to /app
WORKDIR /app

# Copy the current directory contents into the container at /app
ADD . /app

# Install any needed packages specified in requirements.txt
RUN pip install --trusted-host pypi.python.org -r requirements.txt
EXPOSE 80

# Define environment variable
ENV NAME lfmingo

# Run app.py when the container launches
CMD ["python", "app.py"]

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• Create the app (file app.py)

from flask import Flask
from redis import Redis, RedisError 
import os
import socket
   # Connect to Redis
redis = Redis(host="redis", db=0, socket_connect_timeout=2, socket_timeout=2) 
app = Flask(__name__)
@app.route("/")
def hello():
  try:
    visits = redis.incr("counter")
  except RedisError:
    visits = "<i>cannot connect to Redis, counter disabled</i>"
  html = "<h3>Hello {name}!</h3>" \
      "<b>Hostname:</b> {hostname}<br/>" \    
      "<b>Visits:</b> {visits}"
  return html.format(name=os.getenv("NAME", "world"), hostname=socket.gethostname(), visits=visits)
if __name__ == "__main__": 
  app.run(host='0.0.0.0', port=80)

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• Create the file requirements.txt

Flask
Redis

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• Build the app = Create the Docker image

docker image build --tag lfmingo:1.0 .

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• Run the container

docker run -d -p 8080:80 lfmingo:1.0 -n lfmingo

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• Stop and Run again

docker stop lfmingo
docker start lfmingo

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• Share the image into Docker Hub

docker login
docker image tag lfmingo:1.0 lfmingo/lfmingo:1.0
docker push lfmingo/lfmingo:1.0 

Note that the tag must be in format user/image:number

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• Push the image

docker pull lfmingo/lfmingo:1.0
docker run -d -p 8080:80 lfmingo/lfmingo:1.0 -n lfmingo

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Part II: Docker Compose Services on Swarm

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• Define docker-compose-service.yml file

version: "3" 
services:
    web:    
        image: lfmingo/lfmingo:1.0
        deploy:
            replicas: 5 
            resources:
                limits:
                    cpus: "0.1" 
                    memory: 50M
            restart_policy: 
                condition: on-failure
        ports:
            - "8080:80"
        networks: 
            - webnet

networks: 
    webnet:

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• Run the app as a service on a swarm

docker swarm init
docker stack deploy -c docker-compose-services.yaml webserver

To delete the stack docker stack rm webserver

To leave the swarm docker swarm leave --force

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Part II: Docker Compose Stacks on Swarm

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• Define docker-compose-stack.yml file

version: "3" 
services:
    web:    
        image: lfmingo/lfmingo:1.0
        deploy:
            replicas: 5 
            resources:
                limits:
                    cpus: "0.1" 
                    memory: 50M
            restart_policy: 
                condition: on-failure
        ports:
            - "8080:80"
        networks: 
            - webnet
    visualizer:
        image: dockersamples/visualizer:stable 
        ports:
            - "8090:8080" 
        volumes:
            - "/var/run/docker.sock:/var/run/docker.sock" 
        deploy:
            placement:
                constraints: [node.role == manager]
        networks: 
            - webnet
    redis:
        image: redis:4.0.5-alpine
        command: ["redis", "--appendonly", "yes"]
        hostname: redis
        networks:
            - webnet 
        volumes:
            - redis-data:/data 
networks:
    webnet: 
volumes:
    redis-data:

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• Run the app as a stack on a swarm

docker swarm init
docker stack deploy -c docker-compose-stack.yaml webapp

To remove the stack docker stack rm webapp

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Part III: Docker Swarm

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Install docker-machine

OSX

base=https://github.com/docker/machine/releases/download/v0.16.0 &&
  curl -L $base/docker-machine-$(uname -s)-$(uname -m) >/usr/local/bin/docker-machine &&
  chmod +x /usr/local/bin/docker-machine

Windows with GitBash

base=https://github.com/docker/machine/releases/download/v0.16.0 &&
  mkdir -p "$HOME/bin" &&
  curl -L $base/docker-machine-Windows-x86_64.exe > "$HOME/bin/docker-machine.exe" &&
  chmod +x "$HOME/bin/docker-machine.exe"

See https://docs.docker.com/machine/install-machine/

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MacOS / Linux

• Set up the swarm
  • 1 master (Virtual Machines with docker engine)
  • 2 workers (Virtual Machines with docker engine)

docker-machine create master
docker-machine create worker-1
docker-machine create worker-2

You can ssh to worker with: docker-machine ssh <name>

You can discover IP address with: docker-machine ip <name>

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Windows 10

• Set up the swarm
  • 1 master (Virtual Machines with docker engine)
  • 2 workers (Virtual Machines with docker engine)

Launch Hyper-V Manager

• Click Virtual Switch Manager in the right-hand menu
• Click Create Virtual Switch of type External
• Give it the name myswitch, and check the box to share your host machine’s active network adapter

docker-machine create -d hyperv --hyperv-virtual-switch "myswitch" master
docker-machine create -d hyperv --hyperv-virtual-switch "myswitch" worker-1
docker-machine create -d hyperv --hyperv-virtual-switch "myswitch" worker-2

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Windows, MacOS and Linux

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• Create a cluster

In the manager/master machine run:

docker swarm init <IP>

To reobtain the token run (in the master node)

docker swarm join-token worker

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• Initialize the swarm and add nodes

In the workers run

docker swarm join \
    --token <token-obtained-from-master-machine> \
    <ip-master-machine>:2377`

To check the nodes and roles docker node ls

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• Deploy the app on the swarm

In the host machine: docker-machine env <nombre master> and all following docker commands will be run in >nombre master> machine (to reset docker-machine env --unset)

docker stack deploy -c docker-compose-stack.yaml webapp

Run:

docker node ls
docker stack ps webapp  
docker stack services webapp
docker service ls
docker ps
docker-machine ls

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• Re-scaling

Check services with docker service ls

docker service scale webapp_visualizer=2

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• Cleanup and reboot

In master machine:

docker stack rm webapp

In workers:

docker swarm leave --force