Today I was learning about AWS Elastic Beanstalk, here are the notes:

Elastic Beanstalk

• Is the Heroku of AWS
• CloudFormation templates

Platforms

• Docker
• Multi-docker
• Go, Ruby, Python, Node, PHP, .NET (and frameworks)

Web vs Worker

• Web directly to internet
• Worker for background jobs

Web environments

Load-balanced environment

• Uses ASG and set to scale
• Uses ELB

Single-instance environment

• Uses a Public IP address
• No ELB to reduce costs

Deployent policies availables with Elastic Beanstalk

* rolling requires an ELB

All at once deployment

1. Deploys new app version to all instances at the same time.
2. Takes all insttances out of service while deployment process.
3. Servers become available again.

Fastest but dangerous deployment method. In case of failure: You need to roll-back and redeploy original version.

Rolling deployment

1. Deploys the new app version to a batch of instances at a time.
2. Takes batch’s instances out of services while the deployment process.
3. Reattaches updated instances.
4. Repeat with next batches

In case of failure: You need to perform an aditional rolling update in order to roll-back the changes.

Rolling with aditional batch

1. Launches new instance tha will be used to replace a batch.
2. Deploy update app version to new batch.
3. Attach new batch and terminate the existing batch.

• Rolling with additional batch ensure our capacity is never reduced.
• Important for applications were a reduction on capasity could cause availability issues.

In case of failure: Perform aditional rolling update to roll-back changes.

Inmutable

1. Create a new ASG group with EC2 instances.
2. Deploy the updated version o the new EC2 instances.
3. Point the ELB to the new ASG and delete old ASG (which will terminate old EC2 instances).

• Safest way to deploy critical applications.

In case of failure: Terminate new instances since the existing will remain.

Deployment methods

In-place vs Blue/Green

Elastic Beanstalk by default perform in-place updates.

Elastic Beanstalk configuration files

• .ebextennsions -> hidden folder at the root of the project
• .config -> extension of the files inside .ebextensions

Configuration files can config

1. Option settings
2. Linux / Windows server config
3. Custom resources

Environment manifest

Is a file called env.yml which is stored on the root of the project.

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AWSConfigurationTempalteVersion: 1.1.0.0
EnvironmentName: application-prod
SolutionStack: Ruby
EnvironmentLinks:
  WORKERQUEUE: "worker+"
OptionSettings:
  asw:elb:loadbalancer:
    CrossZone: true

Linux Server Configuration

Packages

Download and install prepackaged applications and components

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packages:
  yum:
    libmemcached: []
    ruby-devel: []

Groups

Create Linux/UNIX groups and to assign group IDs

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groups:
  groupAdmin: {}
  groupDev:
    gid: "12"

Users

Create Linux/UNIX users

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users:
  mijail:
    groups:
      - groupAdmin
    uid: 87
    homeDir: "/home/mijail/"

Files

Create files on the EC2 instance (inline or from URL)

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files:
  "/home/mijail/application.yml":
    mode: "000755"
    owner: root
    group: root
    content: |
      SECRET: RandomSecret

Commands

Execute commands on the EC2 instance before app is setup

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commands:
  1_create_root:
    command: mkdir /var/www/app
  2_link:
    command: ln -s /var/www/app /app

Services

Define which services sould be started or stoped when the instance is lauched.

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services:
  sysvinit:
    nginx:
      enabled: true
      ensureRunning: true

Container Commands

Execute commands that affect your application source code. Not refered to docker containers, just application code.

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container_commands:
  0_migrate:
    command: rake db:migrate
  1_assets:
    command: rake assets:precompile

Elastic Beanstalk CLI

• eb init -> configure your project directory
• eb create -> create env
• eb status -> see current status of env
• eb health -> view health info for the instances and overall env
• eb events -> list of events output by EB
• eb logs -> pull logs from a instance
• eb open -> open env website in a browser
• eb deploy -> once the env is runnig deploy an update
• eb config -> take a look at the configuration options available on the running env
• eb terminate -> delete the environment

Elastic Beanstalk Custom Images

When you crete an EB environment you can specify an AMI to use insted of the standart EB AMI

Configuring RDS

• Inside EB
• Outside EB

Inside EB Env

• Generally for development envs
• When the EB env is terminated the DB is also terminated

Outside EB env

• Intended for production environments
• Create the db form RDS separate from EB
• When de EB env is termitaded the DB will remain

Elastic Beanstalk cheat sheet

• Handles deployment from capacity provisioning, load balancing, auto-scaling to application health monitoring.
• When you want to run a web-application but you don’t want to have think about the underlying infrastructure.
• It cost nothing to use Elastic Beanstalk (only resources it provisions eg. RDS, ELB, EC2)
• Recommended for test or development apps. Not recommended for production use (super large enterprises)
• You can choose from the following preconfigured platforms: Java, .NET, PHP, Node, Python, Ruby, Go and Docker.
• You can run containers on EB either in Single-container or Multi-container, thes containers are running on ECS instead of EC2.
• You can launch either a Web Environment or a Worker Environment.
  • Web Environments comes in two types Single-Instance or Load Balanced.
    • Single-Instance env launches a single EC2 instance, an EIP is assigned to the EC2.
    • Load Balanced Env launch EC2s behind an ELB managed by an ASG.
  • Worker environments creates an SQS queue, install the SQS deamon on the EC2 instances, and has ASG scaling policy which will add or remove instances based on the queue size.
• EB has the following deployment policies:
  • All at once takes all sercers out of service, applies changes, put the servers back in service, fast, has downtime.
  • Rolling updates servers in batches, reduced capacity based on batch size.
  • Rolling with additional batch adds new servers in batches to replace old, never reduces capacity.
  • Inmutable creates the same amount of servers, and switches all at once to new servers, removing old servers.
• Rolling deployment policies require an ELB so cannot be used with Single-Instance Web environments.
• In-Place deployment is when deployment occurs within the environment, all deployment policies are In-Place.
• Blue/Green is when deployment swaps environments (outside an environment), When you have external resources such as RDS which cannot be destroyet its suited for Blue/Green.
• .ebextensions is a folder which contains all configuration files.
• With EB you can provide a Custom Image which can imporve provisioning times.
• If you let EB create the RDS instance, that means when you delete your environment it will delete the database. This setup is intended for development and test environments.
• Dockerrun.aws.json is similar to a ECS task definition files and defines multicontainer configuration.