IRIS_Containers_Task

• Running Docker-Compose
• Final Running Website
• Running Containers

Steps:

1. Dockerizing the given rails app.

• Dockerfile:

FROM ruby:2.5.1-stretch

RUN mkdir /railsapp

WORKDIR /railsapp
COPY Gemfile /railsapp/Gemfile
COPY Gemfile.lock /railsapp/Gemfile.lock
RUN bundle install
COPY . /railsapp
RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - \
    && apt install -y nodejs

COPY entrypoint.sh /usr/bin/
RUN chmod +x /usr/bin/entrypoint.sh
ENTRYPOINT [ "entrypoint.sh" ]
EXPOSE 3000

CMD ["rails", "server", "-b", "0.0.0.0"]

• Tried building the image sudo docker build -f Dockerfile -t railsappimg .
• Checked using sudo docker run -p 8080:3000 railsappimg

2. Setting up MySQL container and linking

• Used docker-compose to set-up the app
• No port allocation for mysql on host.
• docker-compose.yml

version: "3.8"
services: 
  web1:
      build: .
      command: bash -c "rm -f tmp/pids/server.pid && bundle exec rake db:create && bundle exec rake db:migrate && bundle exec rails s -p 3000 -b '0.0.0.0'"
      depends_on: 
          - db
      volumes:
          - .:/railsapp
      ports: 
          - "8080:3000"
      links:
          - db
      environment: 
          - CONT="web1"
      env_file: 
          - '.env.web'
      restart: always
   db:
      image: library/mysql:5.7
      volumes: 
          - ../databasebackup/data:/var/lib/mysql
      env_file: 
          - '.env.db'
      restart: always
      expose:
          - '3306'

• Change config/database.yml to:

  default: &default
  adapter: mysql2
  encoding: utf8
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  host: db
  username: <%= ENV["DB_USER"] %>
  password: <%= ENV["DB_PWD"] %>

environment variables are defined in .env.db and .env.web

• Tested the setup using sudo docker-compose up

3. Nginx Reverse Proxy

• Used pre-built nginx image
• Changed the config file to match the requirements.
• No port allocation on host for rails app, only accessible from nginx proxy.
• Modified docker-compose.yml to use nginx reverse proxy service

 version: "3.8"
 services: 
   web1:
       build: .
       command: bash -c "rm -f tmp/pids/server.pid && bundle exec rake db:create && bundle exec rake db:migrate && bundle exec rails s -p 3000 -b '0.0.0.0'"
       depends_on: 
           - db
       volumes:
           - .:/railsapp
       expose: 
           - "3000"
       links:
           - db
       environment: 
           - CONT="web1"
       env_file: 
           - '.env.web'
       restart: always
    db:
       image: library/mysql:5.7
       volumes: 
           - ../databasebackup/data:/var/lib/mysql
       env_file: 
           - '.env.db'
       restart: always
       expose:
           - '3306'
     
     rev_proxy:
       image: nginx:latest 
       depends_on: 
           - web1
           - db
       ports:
           - 8080:8080
       links:
           - web1
       volumes: 
           - ../revprx/nginx.conf:/etc/nginx/nginx.conf
       restart: always

• Any http requests to localhost will be passed to web1 service(rails app)
• Set up proper http headers to abide same-origin
• nginx.conf:

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

http {
    server {
        listen 8080;
        server_name localhost 127.0.0.1;
        location / {
            proxy_pass  http://web1:3000;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Host $http_host;
            proxy_set_header X-NginX-Proxy true;
        }
    }
}

4. Launching more rail apps and loadbalancing.

• Added two more web services from docker-compose
• Final docker-compose.yml

version: "3.8"
services: 
  web1:
      build: .
      command: bash -c "rm -f tmp/pids/server.pid && bundle exec rake db:create && bundle exec rake db:migrate && bundle exec rails s -p 3000 -b '0.0.0.0'"
      depends_on: 
          - db
      volumes:
          - .:/railsapp
      expose: 
          - "3000"
      links:
          - db
      environment: 
          - CONT="web1"
      env_file: 
          - '.env.web'
      restart: always
     
  web2:
      build: .
      command: bash -c "rm -f tmp/pids/server.pid && bundle exec rake db:create && bundle exec rake db:migrate && bundle exec rails s -p 3000 -b '0.0.0.0'"
      depends_on: 
          - db
          - web1
      volumes:
          - .:/railsapp
      expose: 
          - "3000"
      links:
          - db
      environment: 
          - CONT="web2"
      env_file: 
          - '.env.web'
      restart: always

  web3:
      build: .
      command: bash -c "rm -f tmp/pids/server.pid && bundle exec rake db:create && bundle exec rake db:migrate && bundle exec rails s -p 3000 -b '0.0.0.0'"
      depends_on: 
          - db
          - web1
          - web2
      volumes:
          - .:/railsapp
      environment: 
          - CONT="web3"
      expose: 
          - "3000"
      links:
          - db
      env_file: 
          - '.env.web'
      restart: always
            
        
  db:
      image: library/mysql:5.7
      volumes: 
          - ../databasebackup/data:/var/lib/mysql
      env_file: 
          - '.env.db'
      restart: always
      expose:
          - '3306'
  
  rev_proxy:
      image: nginx:latest 
      depends_on: 
          - web1
          - web2
          - web3
          - db
      ports:
          - 8080:8080
      links:
          - web1
          - web2
          - web3
      volumes: 
          - ../revprx/nginx.conf:/etc/nginx/nginx.conf
      restart: always

• Used the default Round-Robin Load balancing.
• nginx.conf:

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

http {          
    upstream railapps {
        server web1:3000 weight=1;
        server web2:3000 weight=1;
        server web3:3000 weight=1;
    }
    server {
        listen 8080;
        server_name localhost 127.0.0.1;

        location / {
            proxy_pass  http://railapps;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Host $http_host;
            proxy_set_header X-NginX-Proxy true;
        }
    }
}

5. Data Persistance

• Used volume mounts for both mysql container and nginx container.
• In docker-compose.yml

[...]
   volumes: 
               - ../databasebackup/data:/var/lib/mysql
[...]
   volumes: 
               - ../revprx/nginx.conf:/etc/nginx/nginx.conf

6. Docker-Compose

• All services are properly linked, so can start all of them with docker-compose up

7. Rate Limiting

• Limited the client to have 3 request per second with maximum of 20 in queue(bursts)
• Modified nginx.conf

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

http {
    limit_req_zone $binary_remote_addr zone=one:10m rate=3r/s;
            
    upstream railapps {
        server web1:3000 weight=1;
        server web2:3000 weight=1;
        server web3:3000 weight=1;
    }
    server {
        listen 8080;
        server_name localhost 127.0.0.1;

        location / {
            proxy_pass  http://railapps;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Host $http_host;
            proxy_set_header X-NginX-Proxy true;

            limit_req zone=one burst=20 nodelay;
        }
    }
}

8. Scheduled Database Dump

• Used crontab in the host.
• Accessed mysqldump in the container using docker-compose exec and executed a shell script to dump the database to host machine everyday
• In /etc/crontab:

0 0     * * *   root    /usr/bin/db_dumper

• In /usr/bin/db_dumper

cd /home/sha68/irissys2/Shopping-App-IRIS
sudo docker-compose exec db bash -c 'mysqldump -p$MYSQL_ROOT_PASSWORD --all-databases' > "/home/sha68/irissys2/databasebackup/db_backup_$(date +"%d_%m_%Y")"