Add gRPC auth token helper

go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/smartystreets/assertions v1.0.1
 	github.com/smartystreets/goconvey v1.6.4
 	github.com/stretchr/testify v1.7.0
+	google.golang.org/grpc v1.40.0
 )
 
 require (
@@ -38,7 +39,6 @@ require (
 	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c // indirect
 	golang.org/x/text v0.3.6 // indirect
 	google.golang.org/genproto v0.0.0-20210602131652-f16073e35f0c // indirect
-	google.golang.org/grpc v1.40.0 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )

grpc/auth.go

@@ -0,0 +1,30 @@
+package grpc
+
+import (
+	"context"
+
+	"github.com/signalfx/golib/v3/sfxclient"
+	"google.golang.org/grpc/credentials"
+)
+
+// SignalFxTokenAuth is a credentials.PerRPCCredentials object that sets an auth token on each gRPC request
+// as expected by our ingest service.
+type SignalFxTokenAuth struct {
+	Token string
+	DisableTransportSecurity bool
+}
+
+var _ credentials.PerRPCCredentials = new(SignalFxTokenAuth)
+
+// GetRequestMetadata returns the metadata with the auth token
+func (a *SignalFxTokenAuth) GetRequestMetadata(ctx context.Context, uri ...string) (map[string]string, error) {
+	return map[string]string{
+		sfxclient.TokenHeaderName: a.Token,
+	}, nil
+}
+
+// RequireTransportSecurity determines whether TLS is required or not.  This will return `true`
+// unless DisableTokenSecurity has been overridden to `true`.
+func (a *SignalFxTokenAuth) RequireTransportSecurity() bool {
+	return !a.DisableTransportSecurity
+}

grpc/auth_test.go

@@ -0,0 +1,27 @@
+package grpc
+
+import (
+	"context"
+	"testing"
+
+	"github.com/signalfx/golib/v3/sfxclient"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestGRPCAuth(t *testing.T) {
+	Convey("grpc auth", t, func() {
+		a := &SignalFxTokenAuth{
+			Token: "test",
+			DisableTransportSecurity: false,
+		}
+
+		So(a.RequireTransportSecurity(), ShouldBeTrue)
+
+		md, err := a.GetRequestMetadata(context.Background(), "")
+		So(err, ShouldBeNil)
+		So(md[sfxclient.TokenHeaderName], ShouldEqual, "test")
+
+		a.DisableTransportSecurity = true
+		So(a.RequireTransportSecurity(), ShouldBeFalse)
+	})
+}