chore: refactor sending telemetry (#15345)

Implements a tailnet API Telemetry controller by refactoring from `workspacesdk`.

chore re: #14729

tailnet/controllers_test.go

@@ -13,6 +13,8 @@ import (
 	"github.com/stretchr/testify/require"
 	"go.uber.org/mock/gomock"
 	"golang.org/x/xerrors"
+	"storj.io/drpc"
+	"storj.io/drpc/drpcerr"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
 
@@ -351,3 +353,157 @@ func (f fakeDERPClient) Recv() (*tailcfg.DERPMap, error) {
 	}
 	return nil, io.EOF
 }
+
+func TestBasicTelemetryController_Success(t *testing.T) {
+	t.Parallel()
+	ctx := testutil.Context(t, testutil.WaitShort)
+	logger := slogtest.Make(t, nil).Leveled(slog.LevelDebug)
+
+	uut := tailnet.NewBasicTelemetryController(logger)
+	ft := newFakeTelemetryClient()
+	uut.New(ft)
+
+	sendDone := make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{
+			Id: []byte("test event"),
+		})
+	}()
+
+	call := testutil.RequireRecvCtx(ctx, t, ft.calls)
+	require.Len(t, call.req.GetEvents(), 1)
+	require.Equal(t, call.req.GetEvents()[0].GetId(), []byte("test event"))
+
+	testutil.RequireSendCtx(ctx, t, call.errCh, nil)
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+}
+
+func TestBasicTelemetryController_Unimplemented(t *testing.T) {
+	t.Parallel()
+	ctx := testutil.Context(t, testutil.WaitShort)
+	logger := slogtest.Make(t, nil).Leveled(slog.LevelDebug)
+
+	ft := newFakeTelemetryClient()
+
+	uut := tailnet.NewBasicTelemetryController(logger)
+	uut.New(ft)
+
+	// bad code, doesn't count
+	telemetryError := drpcerr.WithCode(xerrors.New("Unimplemented"), 0)
+
+	sendDone := make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{})
+	}()
+
+	call := testutil.RequireRecvCtx(ctx, t, ft.calls)
+	testutil.RequireSendCtx(ctx, t, call.errCh, telemetryError)
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+
+	sendDone = make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{})
+	}()
+
+	// we get another call since it wasn't really the Unimplemented error
+	call = testutil.RequireRecvCtx(ctx, t, ft.calls)
+
+	// for real this time
+	telemetryError = drpcerr.WithCode(xerrors.New("Unimplemented"), drpcerr.Unimplemented)
+	testutil.RequireSendCtx(ctx, t, call.errCh, telemetryError)
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+
+	// now this returns immediately without a call, because unimplemented error disables calling
+	sendDone = make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{})
+	}()
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+
+	// getting a "new" client resets
+	uut.New(ft)
+	sendDone = make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{})
+	}()
+	call = testutil.RequireRecvCtx(ctx, t, ft.calls)
+	testutil.RequireSendCtx(ctx, t, call.errCh, nil)
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+}
+
+func TestBasicTelemetryController_NotRecognised(t *testing.T) {
+	t.Parallel()
+	ctx := testutil.Context(t, testutil.WaitShort)
+	logger := slogtest.Make(t, nil).Leveled(slog.LevelDebug)
+	ft := newFakeTelemetryClient()
+	uut := tailnet.NewBasicTelemetryController(logger)
+	uut.New(ft)
+
+	sendDone := make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{})
+	}()
+	// returning generic protocol error doesn't trigger unknown rpc logic
+	call := testutil.RequireRecvCtx(ctx, t, ft.calls)
+	testutil.RequireSendCtx(ctx, t, call.errCh, drpc.ProtocolError.New("Protocol Error"))
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+
+	sendDone = make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{})
+	}()
+	call = testutil.RequireRecvCtx(ctx, t, ft.calls)
+	// return the expected protocol error this time
+	testutil.RequireSendCtx(ctx, t, call.errCh,
+		drpc.ProtocolError.New("unknown rpc: /coder.tailnet.v2.Tailnet/PostTelemetry"))
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+
+	// now this returns immediately without a call, because unimplemented error disables calling
+	sendDone = make(chan struct{})
+	go func() {
+		defer close(sendDone)
+		uut.SendTelemetryEvent(&proto.TelemetryEvent{})
+	}()
+	testutil.RequireRecvCtx(ctx, t, sendDone)
+}
+
+type fakeTelemetryClient struct {
+	calls chan *fakeTelemetryCall
+}
+
+var _ tailnet.TelemetryClient = &fakeTelemetryClient{}
+
+func newFakeTelemetryClient() *fakeTelemetryClient {
+	return &fakeTelemetryClient{
+		calls: make(chan *fakeTelemetryCall),
+	}
+}
+
+// PostTelemetry implements tailnet.TelemetryClient
+func (f *fakeTelemetryClient) PostTelemetry(ctx context.Context, req *proto.TelemetryRequest) (*proto.TelemetryResponse, error) {
+	fr := &fakeTelemetryCall{req: req, errCh: make(chan error)}
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case f.calls <- fr:
+		// OK
+	}
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case err := <-fr.errCh:
+		return &proto.TelemetryResponse{}, err
+	}
+}
+
+type fakeTelemetryCall struct {
+	req   *proto.TelemetryRequest
+	errCh chan error
+}