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ready

Check if a Kubernetes object exists and is ready.

Usage example

In the following example, the ready task checks if a deployment named httpbin-prod exists and its availability condition is set to true, and a service named httpbin exists.

iter8 k launch \
--set "tasks={ready,http}" \
--set ready.deploy=httpbin-prod \
--set ready.service=httpbin \
--set http.url=http://httpbin.default/get \
--set runner=job

Parameters

Name Type Description
deploy string Name of a Kubernetes deployment. The task checks if the deployment exists and its Available condition is set to true.
service string Name of a Kubernetes service. The task checks if the service exists.
ksvc string Name of a Knative service. The task checks if the service exists and its Ready condition is set to true.
timeout string Timeout for readiness check to succeed. Default value is 60s.
namespace string The namespace under which to look for the Kubernetes objects. For experiments that run inside a Kubernetes cluster, the default value of this field is the namespace of the Iter8 experiment; for experiments that run in the local environment, it is the default namespace.

Extensions

Iter8 can be easily extended to support readiness checks for any type of Kubernetes object (including objects with custom resource types). Please consider submitting a pull request for such extensions. Readiness checking in Iter8 involves two templates, namely, task.ready and k.role. Extending the readiness checks to new resource types involves modifying these templates.

Example

Consider the Knative extension for this task; this extension enables Iter8 experiment authors to define readiness check for Knative services. In the following example, the ready task succeed if the Knative service named httpbin exists, and has its Ready condition set to true.

iter8 k launch \
--set "tasks={ready,http}" \
--set ready.ksvc=httpbin \
--set http.url=http://httpbin.default/get \
--set runner=job

The task.ready and k.role were changed in the following ways to create this extension.

The group/version/resource (GVR) and the condition that should be checked for a Knative Service are defined in this template.

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{{- if .Values.ready.ksvc }}
# task: determine if Knative Service exists and is ready
- task: ready
  with:
    name: {{ .Values.ready.ksvc | quote }}
    group: serving.knative.dev
    version: v1
    resource: services
    condition: Ready
{{- include "task.ready.tn" . }}
{{- end }}

The role named {{ .Release.Name }}-ready is extended with the Knative apiGroup.

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{{- if .Values.ready.ksvc }}
- apiGroups: ["serving.knative.dev"]
  resourceNames: [{{ .Values.ready.ksvc | quote }}]
  resources: ["services"]
  verbs: ["get"]
{{- end }}
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