Deploying a simple Rails application with AWS Elastic Beanstalk

rails-elasticbean.txt

Deploying a simple Rails application with AWS Elastic Beanstalk by Julien SIMON, Principal Technical Evangelist @ Amazon Web Services

18/02/2016   
http://www.slideshare.net/JulienSIMON5/deploying-a-simple-rails-application-with-aws-elastic-beanstalk
    
    1. . Create a Git repository with AWS CodeCommit 
      $ aws codecommit create-repository --repository-name blog --region us-east-1 --repository-description "ElasticBeanstalk demo" 
      $ git clone ssh://git-codecommit.us- east-1.amazonaws.com/v1/repos/blog
    
    2. Create a new Rails application
       $ rails new blog 
       $ cd blog 
       $ git add . 
       $ git commit -m "Initial version"
    
    3. Add a ‘post’ resource to the application 
      $ rails generate scaffold post title:string body:text 
      $ bundle exec rake db:migrate $ git add . 
      $ git commit -m "Add post resource" 
      $ rails server
      $ open http://localhost:3000/posts
    
    4. Initialize a Ruby application in Elastic Beanstalk
      $ eb init blog -p Ruby -r eu-west-1 
      $ git add .gitignore 
      $ git commit -m "Ignore .elasticbeantalk directory"
      
    5. Create a ‘blog-dev’ environment 
      Single instance (no auto-scaling, no load balancing), t2.micro instance size (default value) 
        $ eb create blog-dev --single --keyname aws-eb --envvars SECRET_KEY_BASE=`rake secret`
    
    6. Update the code and redeploy on ‘blog-dev’ 
        $ vi app/views/posts/index.html.erb --> "Blog de dev" 
        $ git add app/views/posts/index.html.erb 
        $ eb deploy blog-dev --staged 
        $ git commit -m "Add message on post page" 
        $ eb deploy blog-dev
    
    7. Create a production branch for the blog
       $ git branch prod
       $ git checkout prod 
       Now we have to modify 3 files to add support for Postgres: 
         Gemfile 
         config/database.yml 
         .ebextensions/packages.config
    
    8. Gemfile 
        group :development, :test do 
           # Use sqlite3 as the database for Active Record 
           gem 'sqlite3’ 
        end 
        
        group :production do 
          # Use PostgreSQL as the database for Active Record 
          gem 'pg', '~> 0.18.1’ 
        end
    9. config/database.yml 
         production: 
           <<: *default 
           adapter: postgresql 
           encoding: unicode 
           database: <%= ENV['RDS_DB_NAME'] %> 
           username: <%= ENV['RDS_USERNAME'] %> 
           password: <%= ENV['RDS_PASSWORD'] %> 
           host: <%= ENV['RDS_HOSTNAME'] %> 
           port: <%= ENV['RDS_PORT'] %> 
           These environment variables will be automatically declared by Elastic Beanstalk when we create an RDS instance
           
    10. .ebextensions/packages.config 
          packages:
              yum: 
                postgresql94-devel: [] 
        This directive will install the postgres94-devel package on your instances. It is required to install the ‘pg’ Ruby gem. 
        .ebextensions provides lots of options to configure and customize your Elastic Beansltalk applications.
        The documentation is your friend J https://docs.aws.amazon.com/fr_fr/elasticbeanstalk/latest/dg/ebextensions.html

    11. Commit these changes to the production branch 
          $ git add Gemfile config/database.yml .ebextensions 
          $ git commit -m "Use Postgres for production” 
          $ git push 
    Now let’s create a proper production environment : running in a VPC, auto-scaled, load-balanced, with larger instances and backed by RDS Postgres. Ready? J
    
    11. Create a ‘blog-prod’ environment 
        $ aws ec2 describe-subnets 
        $ export VPC_SUBNETS=subnet-63715206,subnet-cbf5bdbc,subnet-59395b00 
        $ eb create blog-prod -k aws-eb --vpc.id=vpc-def884bb --vpc.elbpublic --vpc.publicip --vpc.elbsubnets 
        $VPC_SUBNETS --vpc.ec2subnets $VPC_SUBNETS --vpc.dbsubnets 
        $VPC_SUBNETS --instance_type m4.large --database.engine postgres --database.version 9.4.5    --database.instance db.m4.large --database.size 5 --database.username YOUR_USERNAME --database.password YOUR_PASSWORD --envvars SECRET_KEY_BASE=`rake secret`
    
    13. Connect on ‘blog-prod’ instances 
          $ ssh -i ~/.ssh/aws-eb ec2-user@IP_ADDRESS 
          $ psql -h RDS_INSTANCE -p 5432 -U YOUR_USERNAME -d ebdb 
          Describe tables: dt 
          Show posts: select * from posts
          
    14. Terminate environments 
        $ eb terminate blog-dev --force
        $ eb terminate blog-prod --force