AWS OpsWorks Stacks (Lifecycle Event)

Overview

• allow to build very fined-grained script to respond to these events
• event comes with stack state JSON (state of the know world: elbs, other instances, rds, etc.)
  • figure out how should my service be configured
  • if instance generates attribute on the fly it is NOT part of stack state

Event Type

• setup
  • trigger
    • instance booted first time, initialization ("user-data on steroids")
    • compare "cloud-init" on normal EC2 instance
  • use cases
    
    • install necessary packages, applications (e.g. Apache, Tomcat)
  • Includes "configure" and "deploy" events
• configure 
  • trigger
    • any instance enters or leaves online state
      • includes newly booted instance
        • e.g. after auto-healing
      • EIP associated/disassociated
      • ELB attached/detached from a layer   
  • use cases
    
    • ELB setup, replication etc.
    • Database adds ACL entry that allows instance to connect to it
    • MongoDB, Cassandra, Kafka - setup replication    
  • There is a new node in the system - "do I need to reconfigure myself?"|
  • Database is gone - "what do I do?"
• deploy
  • trigger
    • explicitly triggering deployment (via UI/API)
  • use cases
    • new version of Java application
      • application server downloads the code
      • restart server
    • generic hook (ssh, rsync)
• undeploy 
  • use cases     
    • large number of PHP "virtual hosts"     
      •  you remove tenant and get rid of his "virtual host"
• shutdown
  • trigger
    • instance is about to be terminated
  • use cases
    • gracefully stop application
    • upload logs
  • configurable timeout