# Elastic Beanstalk (EB)  
    PaaS for DevOps; app container; handles all underlying AWS infrastructure configuration, requirements, and deployment; (capacity provisioning, load balancing, auto-scaling, application health monitoring); can upload/update code; EB is sort of a GUI version of CloudFormation   

    alt: Heroku  https://www.heroku.com/ ; BlueMix (IBM)   

    - Precursor of ECS (Docker) and OpsWorks (Chef/Puppet).  
    - Utilizes ECS if Environment is Docker 
    
    - Apps are updatable  
    - Apps can be modularized into multiple EB apps  
    - Apps can have multiple environments; Prod, Staging, Dev, V1, V2, ...
    - Environments can be single instance or scalable  
    - Environments can be web server or worker  
        @ Worker environment: on-demand workloads or scheduled tasks; msg per SQS/POST   
    - Apps are uploaded as .zip or .war file  

    - PLATFORMS available:  
        - Preconfigured    
            Node.js (Nginx|Apache), PHP (Apache), Python (Apache), Ruby (Passenger|Puma), Tomcat (Java), .NET (IIS), Java, Go, Packer    
        - Preconfigured - Docker    
            GlassFish (Java EE App Server), Go, Python    
        - Generic    
            Docker  
            Multi-container Docker  

    - DEBUGGING 
        @ EB Dashboard > Logs > Request Logs 
            > "Last 100 lines" | "Full Logs"  (downloadable)  
    
    - SHUTDOWN 
        @ EB > {appname} > Actions (menu) > Delete application > Delete (button)  
        @ RDS > Instances > {name} > Delete (button)  
        @ ElastiCache > Redis > {name} (select the CLUSTER) 
            > Delete (button) > Backup: no > Delete  
        @ VPC > Security Groups > ... delete ...
        
        - SECURE :: Prevent credentialed User, e.g., Travis-CI bot, 
          from programmatic (automatic) access ...
            @ IAM > User > Security credentials 
                > Access Key > "Make inactive"

    - @ EB > Create ...  
        Application information  
            Application name:  
        Base configuration  
            Platform (dropdown-menu)
                - Preconfigured    
                - Preconfigured - Docker    
                - Generic    
            Application code: 
                - Sample application (check-box)  
                - Upload your code   (check-box)  
        > Configure more options | Create application  (buttons)  
        > Configure more options  
            Configuration presets  
                - Low cost (Free Tier eligible)  (check-box)
                - High availability  (check-box)
                - Custom confguration  (check-box)

            Change platform configuration 
            (Also available @ EB Dashboard, post-creation)
               Tags, Software, Capacity, Load balancer, Security, Monitoring, Instances, Rolling updates and deployments, Notifications

    - @ EB > Configuration
        > Security
            - Service role
            - Virtual machine permissions
                EC2 key pair: (add key-pair for SSH access)
                IAM instance profile: (default)

        > Rolling updates and deployments: 
            Deployment policy:   "all at once" | immutable  
            Rolling update type: "all at once" | immutable  
        
        > Database  
            AWS Recommendation: Provision separately (@ RDS), 
            then connect to EB, else deleting EB app deletes database too.    

    - SSH into per normal EC2 method 
        ssh ec2-user@IP_ADDR -i ~/.ssh/KEYNAME.pem  

    - AWS EB CLI  
        DevGuide  https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/eb-cli3-install.html  
        Ref       https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/eb3-cmd-commands.html  

        - awsebcli; is NOT aws-cli (separate app)
        - Requires Python 2.7/3.4
            $ pip install awsebcli --upgrade --user

            $ mkdir HelloWorld
            $ cd HelloWorld
            $ eb init -p PHP
            $ echo "Hello World" > index.html
            $ eb create dev-env
            $ eb open
            $ eb deploy ENVIRONMENT_NAME  # deploy

# Docker @ EB 
# ===========
"11 Multi-Container Deployments to AWS"

    @ AWS > EB > "Create New Application" (button)  
        Application Name: multi-docker  
             Description: 
        > "Create one now" (button)  
        > "Web server environment" (check-box)  
            Create a web server environment  
                Environment information  
                    Application name: multi-docker     (auto-filled)  
                    Environment name: MultiDocker-env  (auto-generated)  
                              Domain: (leave-blank).us-east-1.elasticbeanstalk.com  
                         Description:  
                Base configuration  
                            Platform: "Preconfigured platform" (check-box)  
                                          "Multi-container Docker" (select; dropdown-menu)  
                    Application Code: "Sample application" (check-box; default)  
                
                > Create environment (button)