Refactor interceptor main package

[savitaashture]

Changes

Fixes: #1441

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Release Notes

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/interceptors/server/server.go	77.7%	57.6%	-20.0

[savitaashture]

The following is the coverage report on the affected files. Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File Old Coverage New Coverage Delta
pkg/interceptors/server/server.go 77.7% 57.6% -20.0

Coverage decreased because in code we are using

secret, err := secretInformer.Get(ctx).Lister().Secrets(system.Namespace()).Get(os.Getenv(interceptorTLSSecretKey))
                        if err != nil {
                                logger.Errorf("failed to fetch secret %v", err)
                                return nil, nil
                        }

and from test even if create secret object informer won't able to get the data
because of that some parts of code is not covered

[khrm]

/approve

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: khrm

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[dibyom]

I think we can refactor the functions a bit and add some tests - we've had a few bugs around this behavior so its not ideal to have not tests for it.

For GetTLSData - we could use a fakesecretinformer + pass in namespace and secret name as arguments to the function
For UpdateCACertToClusterInterceptorCRD we can either extract the code under the go routine into its own function to test or use a fake clock

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/interceptors/server/server.go	77.7%	76.6%	-1.1

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/interceptors/server/server.go	77.7%	77.3%	-0.4

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/interceptors/server/server.go	77.7%	79.3%	1.6

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-triggers-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/interceptors/server/server.go	77.7%	79.3%	1.6

[savitaashture]

@dibyom PR is ready
PTAL
Thank you

[dibyom]

/lgtm

Thank you!

[dibyom]

/lgtm