Where will the Application Metadata be defined

[wonderflow]

Now we have Configuration to combine multiple components together which define an Application instance, but if we want to define multiple applications and there will be some dependency on these applications. So we may need a place (or a concept) to define Application Metadata.

Application Metadata is used to store application level information, such as application logo, providers, maintainers, dependencies, etc. We will be able to launch a set of applications if we have defined the application metadata.

For example, we define this Application Meta

apiVersion: core.hydra.io/v1alpha1
kind: ApplicationMeta
metadata:
  labels:
    version: 1.0.0   
spec:
  appName: edas-console
  maintainer: hydra
  logo: /path/to/logo.svg
  components:
    - name: comp1
      metadata:
        version: 1.0.0
        componentRef: compx
    - name: comp2
      metadata:
        version: 1.2.0
        componentRef: compy 
  dependency: 
    - zookeeper
    - kafka      
  parameters:
    - name: parma1
      value: value1

With ApplicationMeta we will be able to define application relationships.

[technosophos]

Do we need this? Or can we just add a few labels to the OperationalConfiguration and get the same thing?

[vturecek]

We already have the perfect construct in the spec for exactly this scenario: scopes! An "application metadata" scope can easily be defined to handle this, except maybe the dependencies, but I'm not sure what that dependency tracking would do anyway.

Nonetheless, I think an application metadata scope might even be a candidate for a core scope, if we feel strongly enough about it.

[wonderflow]

@vturecek I also think scope maybe a good option to solve this scenario. \cc @resouer

[technosophos]

Is someone working on defining an Application Metadata scope? Currently, only Network and Health scopes are defined.

[mikkelhegn]

I will take a stab as defining this, but I have a few questions:

@wonderflow - can you help me understand the 'dependencies' and 'components' part of your example?

[wonderflow]

@hongchaodeng will give a PR, then we can discuss from that