AWS CodeDeploy

Application

• Logical container for revision, deployment configuration and deployment groups (target instances)
• Has Name
  
  • e.g. "All", "PaymentService"

Application Revision

• Archive containing
  • Source files, binary objects, etc.
  • AppSpec file 
• Storage (Repository)
  
  • S3 - identified by S3 object Key/ETAG
    • command: "aws deploy push"
  • GitHub - commitId
  • BitBucket
• Target Revision
  • Most recent revision
• Not every application revision must be deployed

AppSpec

• YAML file
• Maps source files to the destination
• Specifies custom permissions
• Specify scripts to be run at various stages
  • Series of lifecycle events (hooks)
  • Agent retrieves the lists of scripts, executes them and logs output
• At the root directory
• Maps sources files to their destination on disk
• Defines hook scripts
• Template
  • os [linux, windows]
  • files
  • permissions (linux only)
  • hooks
    • Specify: location, timeout, runas
    • types
      • ApplicationStop
      • BeforeInstall
      • AfterInstall
      • ApplicationStart
      • ValidateService

Deployment Group

• Individual instances
  • Individually tagged (union of all tags)
  • On-premise
• AutoScaling Group
  • deployment triggered when new instance is launched
  • do not associate multiple Deployment Groups with the same ASG
    • multiple deployments will be started at once on the same instance 

Security

• IAM Instance Profile
  • agent can access S3/GitHub
• Service Role
  • AWS CodeDeploy can read instance tags/ASG groups

Deployment Configuration

• Predefined
  • One at a time
  • Half at a time
  • All at once
• MinimumHealthyHosts 
  • healthy hosts must be available during deployment
  • determine if overall deployment suceeded
  • e.g. Fleet = 9, MinimumHealthyHosts = 6, Deploys to max 3 at a time
  • specified as Absolute or Percentage

CodeDeploy Agent

• Runs on machine
• Configuration
  • log_aws_wire = detailed wire logs
  • wait_between_runs = default 1 second

On-premise deployment

• Create IAM user for each instance (instead of instance profile)
• Register instance with CodeDeploy (instead of Tag)
• Cannot participate in ELB/ASG
• Additional cost

Health 

• CodeDeploy determines the health status
• Factors
  • RevisionHealth
    • Current - revision matches last successful deployment
    • Old - revision matches old version
    • Unknown - revision not installed successfuly 
  • InstanceHealth
    • Healthy - was last deployment successful
    • Unhealthy - deployment failure, or not attempted
• It does not have any healthcheck (like ELB)
• The ValidateApplication can be used for InstanceHealth
  • fail deployment if fails
• Health status in DeploymentGroup is monitored
• Deployment fails if healthy instances count < MinimumHealthyHosts
• Deployment Order
  • InstanceHealth: Unhealthy
  • RevisionHealth: Unknown
  • RevisionHealth: Old
  • RevisionHealth: Current

   

Misc

• Performs AZ striping to minimize risk
• Based on Amazon internal tool: Apollo

Events

• Lifecycle events
  • DeploymentStart
  • DeploymentSuccess
  • DeploymentFailure
  • InstanceStart
  • InstanceSuccess
  • InstanceFailure
• Target
  • SNS