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ctx.component

The ctx.component value is the component handle for the component in scope: the component a custom command declares, or the component a lifecycle hook runs for. It has the same attributes as the handle returned by components.get.

Usage​

ctx.component.name
ctx.component.stack
ctx.component.vars["region"]
ctx.component.exec(["./smoke-test"])

Returns​

A read-only component handle, or None when no component is in scope. The handle exposes name, type, stack, implementation, path, vars, settings, metadata, env, config, and the exec method.

Entry pointctx.component
Custom command that declares component:The command's component. Atmos resolves it on first attribute access, so a script that never reads it never pays for the lookup.
Custom command without component:None
Lifecycle hookThe hook's component, built from the hook runner's snapshot, which includes inherited settings. It does not re-resolve the stack or fetch Terraform outputs.
Aggregate hook without a component bindingNone
Workflow or standalone scriptNone

Steps inside parallel and matrix groups inherit the component of the step that contains them.

Reading an attribute of None, for example ctx.component.stack in a workflow, fails with NoneType has no .stack field or method. Check the value first, or resolve the component explicitly with components.get.

Lazy resolution uses the script's invocation deadline. To bound a lookup with a task timeout, call components.get inside the task. Read the reference fields you need from ctx.component before starting parallel tasks.

Examples​

Deploy a command's component and its peers​

commands:
  - name: deploy-peers
    arguments:
      - name: component
        provides: component
        required: true
    flags:
      - name: stack
        shorthand: s
        provides: stack
        required: true
    component:
      type: application
    steps:
      - name: deploy
        type: script
        interpreter: starlark
        script: |
          stack = ctx.component.stack

          def deploy(name, stack):
              peer = components.get(name = name, stack = stack, type = "application")
              return peer.exec(["./deploy"]).stdout

          output = steps.parallel(
              tasks = [
                  steps.task(name = n, function = deploy, args = [n, stack], timeout = "5m")
                  for n in ["api", "worker"]
              ],
              max_concurrency = 2,
          )

Guard for a missing component​

if ctx.component == None:
    fail("run this script from a command or hook that has a component")
ui.info("Checking {} in {}".format(ctx.component.name, ctx.component.stack))

Use inherited settings in a hook​

def post_apply():
    policy = ctx.component.settings.get("post_apply", {})
    if not policy.get("enabled", False):
        return
    ctx.component.exec(policy.get("command", ["./smoke-test"]))

post_apply()

Related​