allow linking using ServiceBinding without ServiceBindingOperator

[kadel]

Goal

For developer to be able to link components and applications without the service binding operator having to be installed (self-service)

Acceptance Criteria

• odo link <service-name> should work without having Service Binding Operator installed
• odo link <component-name> should work without having Service Binding Operator installed
• odo unlink should work correctly with links that don't use Service Binding Operator
• odo describe should work correctly (displaying links, evns etc...) with links that don't use Service Binding Operator

Dependencies

Need access to the service binding library in order for this work to begin.

JIRA Epic Tracking

ODO-59

[kadel]

I've done a small POC based on the changes introduced in redhat-developer/service-binding-operator#919

Thanks to the changes in that PR it is possible to easily create binding without an operator.
https://github.com/kadel/odo/blob/f87c8aa3acc3908d093fa5ef8d3f57cd27036295/pkg/odo/cli/component/common_link.go#L322-L334

mgr, _ := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
	Scheme: runtime.NewScheme(),
})
out, _ := json.MarshalIndent(o.serviceBinding, " ", " ")
fmt.Printf("%s\n", string(out))
pipeline := builder.DefaultBuilder.WithContextProvider(context.Provider(o.KClient.DynamicClient, context.ResourceLookup(mgr.GetRESTMapper()))).Build()
repeat, err := pipeline.Process(o.serviceBinding)
// you can read secret name from the passed service binding... Status.Secret
// for unbind the passed service binding instance must have deletetion timestamp set
out2, _ := json.MarshalIndent(o.serviceBinding, " ", " ")
fmt.Printf("%s\n", string(out2))
fmt.Println(repeat)
fmt.Println(err)

[girishramnani]

there is a complexity in writing tests ( we install SBO cluster wide so we cannot write test for testing this feature) so we would expose an env variable to skip the SBO's usage. maybe SKIP_SBO?

[girishramnani]

We can skip SBO installation on minikube and so all tests would use this feature

[dharmit]

• When using the Operator, it provides more features than using it as library
• Other tools can understand Service Binding resources
  • ODC understands and draws it on the UI.
• SBO also provides auto update feature. When annotation of CRD changes, SBO automatically injects it into the Deployment
• Without Operator, you wouldn't be creating a Binding resource on the cluster but injecting the env vars directly into the Deployment.
• odo wants to do it without the Operator as well because installing Operator is admin task and would compel a user to install Operator first.

[kadel]

This was solved only partially.
There is still one big problem #4965