[NiFiDataflowTest] Extends Operator to manage Flow test validation

[juldrixx]

From nifikop created by erdrix: Orange-OpenSource/nifikop#115

Feature Request

Is your feature request related to a problem? Please describe.

There is no way to automate NiFi datafllow validation test.

Describe the solution you'd like to see

Define a resource like NifiDataflowFunctionalTest to define a list of test to play. Something like :

nifiDataflowTest:
  nifiDataflowRef: NifiDataflowSpec
  inputsData:
    - content: string
      attributes: map[string]string
      injectComponentRef: string
  checkAssertions:
    - connectionRef: string
      content: 
        kind: [exactlyMatch | regexMatch]
        value: string
      attributes: map[string]{kind: [exactlyMatch | regexMatch], value: string}
  disableComponentRefs: list(string)

With a logic :

• Deploy the nifi flow specified in the nifiDataflowTest.nifiDataflowRef ,
• Disable all components referenced in nifiDataflowTest.disableComponentRefs ,
• Stop all components with an incoming connection listed in nifiDataflowTest.checkAssertions[*].connectionRef ,
• Create a GenerateFlowfile for each elements of nifiDataflowTest.inputsData and create a connection to the component referenced in nifiDataflowTest.inputsData[*].injectComponentRef
• Then start all the other components,
• check, for all elements of nifiDataflowTest.checkAssertions[*].connectionRef,if the connection contains an element, if so, compare the content and attributes of the flowfile with the associated. assertion If it doesn't match = Test failed, if it does match, start the output component of the connection. And this until one assertion fails or all assertions have