Application Template YAML Specification

In order to simplify the management and deployment of distributed applications, iofogctl provides the ApplicationTemplate kind.

Application Templates allow users to specify an Application once and deploy it many times with different variables. Application Templates do this by allowing users to create Template Variables which can be modified every time an Application is deployed.

To deploy Applications from a Template, first an Application Template must be deployed through iofogctl deploy -f template.yaml. An Application Template YAML spec contains an Application spec with Templated Variables.

apiVersion: iofog.org/v2
kind: ApplicationTemplate
metadata:
  name: my-template
spec:
    name: my-template
    description: My app template
    variables:
    - key: agent-name # Templated variable pertaining to value in spec.application.microservices[0].agent.name below
      description: Name of Agent to deploy Microservices to
      defaultValue: zebra-1
    application: # Typical Application kind spec (fields omitted for simplicity)
      routes:
      ...
      microservices:
      - name: heart-rate-viewer
        agent:
          name: "{{agent-name}}" # Templated Variable (quotation marks are required)
        ...
      ...

Templated Application YAML Specification

Once an Application Template has been created, the following Application YAML can be used to deploy an Application from the Template with the requisite variables specified:

apiVersion: iofog.org/v2
kind: Application
metadata:
  name: my-app
spec:
  template:
    name: my-template
    variables:
      - key: agent-name
        value: zebra-2