Listing workflows by hardware without any workflows returns GRPC error

[invidian]

Expected Behaviour

When listing workflows by hardware, which do not have any workflows assigned, empty list of workflows should be returned.

Current Behaviour

Currently server logs the following error and returns error to the client, when given hardware ID does not have any associated workflows:

tink-server_1  | ERROR: 2020/12/14 13:52:48 grpc: server failed to encode response: rpc error: code = Internal desc = grpc: error while marshaling: proto: Marshal called with nil

    main_test.go:38: listing workflows should succeed, got: rpc error: code = Internal desc = grpc: error while marshaling: proto: Marshal called with nil

Steps to Reproduce (for bugs)

1. go mod init foo
2. Create file called main_test.go with the following content:

package main

import (
  "context"
  "os"
  "testing"

  "github.com/google/uuid"
  "github.com/tinkerbell/tink/client"
  "github.com/tinkerbell/tink/protos/workflow"
)

func listWorkflowsByHardwareID(t *testing.T, hardwareID string) *workflow.WorkflowContextList {
  if hardwareID == "" {
    t.Fatalf("Hardware ID can't be empty")
  }

  envVars := map[string]string{
    "TINKERBELL_GRPC_AUTHORITY": "127.0.0.1:42113",
    "TINKERBELL_CERT_URL":       "http://127.0.0.1:42114/cert",
  }

  for k, v := range envVars {
    if err := os.Setenv(k, v); err != nil {
      t.Fatalf("setting %q environment variable: %v", k, err)
    }
  }

  conn, err := client.GetConnection()
  if err != nil {
    t.Fatalf("getting Tinkerbell connection: %v", err)
  }

  c := workflow.NewWorkflowSvcClient(conn)

  list, err := c.GetWorkflowContextList(context.TODO(), &workflow.WorkflowContextRequest{WorkerId: hardwareID})
  if err != nil {
    t.Fatalf("listing workflows should succeed, got: %v", err)
  }

  return list
}

func Test_Listing_workflows_by_non_existent_hardware_ID_does_return_empty_list(t *testing.T) {
  listWorkflowsByHardwareID(t, uuid.New().String())
}

func Test_Listing_workflows_for_existing_hardware_ID_does_return_empty_list(t *testing.T) {
  l := listWorkflowsByHardwareID(t, "9ef087c3-4d9f-16ed-777a-ae7583fc5030")

  if len(l.GetWorkflowContexts()) == 0 {
    t.Fatalf("list should not be empty")
  }
}

3. Make sure values for env variables and hardware ID in Test_Listing_workflows_for_existing_hardware_ID_does_return_empty_list test are set correctly.
4. Run go test -v.

Context

While working on https://github.com/tinkerbell/cluster-api-provider-tink, we want to find hardware IDs which do not have any workflows associated, to select them
as "available" workers.

Your Environment

Tinkerbell version 9c52cca.

[tstromberg]

Thank you for the detailed test case. This sounds like a fairly trivial issue to fix. Any volunteers?

[chrisdoherty4]

The Tink CLI has been deprecated and removed in #654. This issue is now obsolete.