[META] Make Jenkins infrastructure setup public

[dblock]

The Jenkins instance that runs CI/CD jobs is setup via CDK. There's no reason why that should not be OSS AFAIK so that anyone can deploy a similar instance.

Work checklist:

• Create base Jenkins CDK codebase
  • Base CDK Project #10
  • Create build and test GHA workflow #12
  • Deploy main jenkins instance
  • Follow security guidance for locking down the instance
  • Add instance health monitoring
  • Create a health dashboard
• Create stack for manual secrets deployment
  • House and deploy certs
  • House and deploy github account credentials
  • Setup Agent node config #23
• Deploy operational instance
  • Install plugins
  • Create access logs S3 buckets #25
  • Setup OpenId Connect for Jenkins Cluster Setup #24
  • Load jenkins system configuration #42
• Release Process
  • Deployment process for Beta #43
  • Config the environment for release to beta #61
  • Data retention for Jenkins #85
  • Config the environment for release to prod
  • Finalize any requirements/features before initial release
• Post Release
  • Add job specific monitors / alarms #87
  • Load saved build scripts from DLS
  • Migrate existing configuration
    • Open-source all CI/CD scripts and configuration that runs in Jenkins  #38
  • Validate deployment
  • Job Canary

Open questions:

• How can we make sure that we can recover from a down jenkins main node?

[peternied]

Major headway on this issue with #26 getting merged

[gaiksaya]

Jenkins is public. Access it here: https://build.ci.opensearch.org/