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Section components

components:
- name: external-dns
  source:
    dir: components/external-dns
    git:
      remote: https://github.com/epam/hub-kubeflow-components.git
      ref: main
      subDir: external-dns
  depends:
  - cert-manager

Above you can see external-dns component sources are under ./components/external-dns/ directory.

Section components.source.git section is optional. If not specified then hubctl stack init will not pull the component from git repository if this component does not exist. This operation happens during hubctl stack init

Section components.depends defines dependency between components. This takes effect on the:

  • Components deployment run-list hubctl will schedule component deployment in the order of dependency and then in order of declaration. User can overwrite order by declaring section lifecycle.order in stack manifest.
  • Parameters resolution. Let's say there are two components who output the same parameter. Section depends will tell to hubctl which component parameters must be taken as input.

Component Deployment Hooks

Sometimes before or after a component deployment, User need to perform an action that extends the component and often is environment or context-specific. To achieve that component lifecycle hooks were introduced. This approach allows keeping components KISS and if-less. Please refer to the example below:

components:
- name: external-dns
  source:
    dir: components/external-dns
  hooks:                                # optional
  - file: bin/do-something              # rmandatory, relative to stack manifest file
    brief: Some description of my hook  # optional, brief description for hook
    error: ignore                       # optional, default is `error: fail`
    triggers:                           # mandatory, when hook should be triggered. Accepts wildcards sich as `*-deploy` or `post-*`
    - pre-deploy
    - post-undeploy

There are 2 hooks in the example:

  • File pre-deploy-hook from the .hub directory relative to the directory where the Hub manifest file is located (hub.yaml) will be executed BEFORE external-dns component is deployed. error: ignore means that stack deployment will continue even if there is an error in the hook (it exits with non 0 exit code)
  • File post-deploy-hook from the .hub directory relative to the directory where the Hub manifest file is located (hub.yaml) will be executed AFTER external-dns component is deployed.

Additionally,

  • triggers array also supports regular expressions, such as *-deploy or post-*
  • All hooks matching the expression will be executed, and hook order from the hooks list will be maintained.
Last update: May 1, 2023