GoPanic after handling inproperly configured function

[nce]

We raised the below gopanic during development of a new function. I guess we forgot/didn't set the rsp.Desired.Composite.Ready or have some other weirdness in our function. I'll have to investigate on our end what's really causing this, but still, i think the sequencer shouldn't just die bc/ of that.

I suggest a validation before setting the state, but i wouldn't mind if you close this issue, as it's probably a minor issue for you.

What happened?

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x15a837f]

goroutine 50 [running]:
main.(*Function).RunFunction(0xc0005584f0, {0x17a4520?, 0x1695e764a?}, 0xc0001708c0)
    /fn/fn.go:170 +0x199f
github.com/crossplane/function-sdk-go/proto/v1._FunctionRunnerService_RunFunction_Handler.func1({0x1c35d20?, 0xc00048d170?}, {0x18d9dc0?, 0xc0001708c0?})
    /go/pkg/mod/github.com/crossplane/function-sdk-go@v0.5.0/proto/v1/run_function_grpc.pb.go:130 +0xcb
github.com/crossplane/function-sdk-go.Serve.(*ServerMetrics).UnaryServerInterceptor.UnaryServerInterceptor.func5({0x1c35d20, 0xc00048d170}, {0x18d9dc0, 0xc0001708c0}, 0x41d245?, 0xc000010120)
    /go/pkg/mod/github.com/grpc-ecosystem/go-grpc-middleware/v2@v2.3.0/interceptors/server.go:22 +0x275
github.com/crossplane/function-sdk-go/proto/v1._FunctionRunnerService_RunFunction_Handler({0x17a4520, 0xc0005584f0}, {0x1c35d20, 0xc00048d170}, 0xc00024a500, 0xc000010288)
    /go/pkg/mod/github.com/crossplane/function-sdk-go@v0.5.0/proto/v1/run_function_grpc.pb.go:132 +0x143
google.golang.org/grpc.(*Server).processUnaryRPC(0xc00054c908, {0x1c35d20, 0xc0001beff0}, 0xc00024c1a0, 0xc000094ae0, 0x28801f0, 0x0)
    /go/pkg/mod/google.golang.org/grpc@v1.78.0/server.go:1428 +0x1192
google.golang.org/grpc.(*Server).handleStream(0xc00054c908, {0x1c36648, 0xc00054ab60}, 0xc00024c1a0)
    /go/pkg/mod/google.golang.org/grpc@v1.78.0/server.go:1832 +0xdc6
google.golang.org/grpc.(*Server).serveStreams.func2.1()
    /go/pkg/mod/google.golang.org/grpc@v1.78.0/server.go:1063 +0x7f
created by google.golang.org/grpc.(*Server).serveStreams.func2 in goroutine 31
    /go/pkg/mod/google.golang.org/grpc@v1.78.0/server.go:1074 +0x11d

How can we reproduce it?

I'll try to debug what fields we are setting wrong, but can't promise anything.

What environment did it happen in?

Function version: 0.5.0

cloud provider or hardware configuration:

• Kubernetes version: 135
• Kubernetes distribution: eks

[bobh66]

Are you using either the deletion sequencing or reset composite readiness options? Or is this just doing sequencing with no other inputs set?

[nce]

This part of the composition looks like this:

  - step: run-the-template
    functionRef:
      name: function-flux-remote-connection <-- self developed function currently in dev/test
  - step: detect-readiness
    functionRef:
      name: function-auto-ready
  - step: sequence-creation
    functionRef:
      name: function-sequencer
    input:
      apiVersion: sequencer.fn.crossplane.io/v1beta1
      kind: Input
      resetCompositeReadiness: true
      enableDeletionSequencing: true
      replayDeletion: true
      usageVersion: v2
      rules:
      - sequence:
        - accessentry
        - accesspolicyassociation

My current debugging involves these additions - in our function - after which the panic disappears:

...
	desiredComposite, err := request.GetDesiredCompositeResource(req)
	if err != nil {
		response.Fatal(rsp, errors.Wrap(err, "cannot get desired composite resource"))
		return rsp, nil
	}
...
	if err := response.SetDesiredCompositeResource(rsp, desiredComposite); err != nil {
		response.Fatal(rsp, errors.Wrap(err, "cannot set desired composite resource"))
		return rsp, nil
	}

The panic happens after the successful run of our function, which involves the creation of the a few composed resources.
The sequencer pod logs that the accessentry is not ready yet, then dies. Deletion is currently not looked at

[bobh66]

Does the problem go away if you disable resetCompositeReadiness?