Component lifecycle hooks

[oginskis]

As a DevOps engineer, I assemble stacks from generic components. Sometimes, before or after I deploy a component, I need to perform an action that extends the component and often is environment or context-specific.

An example:

The Grafana component in GCP Support MGMT Stack

Responsibilities of the generic Grafana component:

• Template values.yaml file of the corresponding Helm chart
• Run helm install to deploy the component to Kubernetes
• Run helm delete to undeploy the component from Kubernetes

Responsibilities of the lifecycle hooks:

• Before deploy

  • Prepare Kubernetes context for deployment (the way how to retrieve the context differs from cloud to cloud)

• After deploy

  • Deploy GCP Support data sources and dashboards to Grafana

• Before undeploy

  • Prepare Kubernetes context for deployment (the way how to retrieve the context differs from cloud to cloud)

This approach allows keeping Grafana component KISS, if-less programming, and no cloud or env-specific code in the body of the component.

Agreed on:

- name: mgmt-grafana
  source:
    dir: components/grafana
    git:
      remote: https://github.com/agilestacks/google-components.git
      subDir: grafana
  hooks:
  - brief: Set GKE context
    file: .hub/gke-context
    triggers:
    - pre-*deploy
  - brief: Deploy datasource
    file: .hub/datasource
    triggers:
    - post-deploy      
  - brief: Deploy dashboard
    file: .hub/dashboard
    triggers:
    - post-deploy    

To do:

• document hub CLI local setup
• development
• unit test
• release
• on error fail flag
• print env vars of hooks
• if file not found - fail

[akranga]

Shema should be also updated schema

[akranga]

Closing this issue due to inactivity