Merge pull request #15 from github/lightstep

Add OpenTelemetry instrumentation

client.go

@@ -5,6 +5,7 @@ import (
 	"crypto/tls"
 	"fmt"
 
+	"github.com/opentracing/opentracing-go"
 	"golang.org/x/crypto/ssh"
 )
 
@@ -52,6 +53,9 @@ func WithTLSConfig(tlsConfig *tls.Config) ClientOption {
 // JoinWorkspace connects the client to the server's Live Share
 // workspace and returns a session representing their connection.
 func (c *Client) JoinWorkspace(ctx context.Context) (*Session, error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "Client.JoinWorkspace")
+	defer span.Finish()
+
 	clientSocket := newSocket(c.connection, c.tlsConfig)
 	if err := clientSocket.connect(ctx); err != nil {
 		return nil, fmt.Errorf("error connecting websocket: %v", err)
@@ -120,6 +124,9 @@ func (s *Session) openStreamingChannel(ctx context.Context, id channelID) (ssh.C
 		return nil, fmt.Errorf("error getting stream id: %v", err)
 	}
 
+	span, ctx := opentracing.StartSpanFromContext(ctx, "Session.OpenChannel+SendRequest")
+	defer span.Finish()
+
 	channel, reqs, err := s.ssh.conn.OpenChannel("session", nil)
 	if err != nil {
 		return nil, fmt.Errorf("error opening ssh channel for transport: %v", err)

port_forwarder.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"io"
 	"net"
+
+	"github.com/opentracing/opentracing-go"
 )
 
 // A PortForwarder forwards TCP traffic over a LiveShare session from a port on a remote
@@ -108,6 +110,9 @@ func awaitError(ctx context.Context, errc <-chan error) error {
 
 // handleConnection handles forwarding for a single accepted connection, then closes it.
 func (fwd *PortForwarder) handleConnection(ctx context.Context, id channelID, conn io.ReadWriteCloser) (err error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "PortForwarder.handleConnection")
+	defer span.Finish()
+
 	defer safeClose(conn, &err)
 
 	channel, err := fwd.session.openStreamingChannel(ctx, id)

rpc.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"sync"
 
+	"github.com/opentracing/opentracing-go"
 	"github.com/sourcegraph/jsonrpc2"
 )
 
@@ -26,6 +27,9 @@ func (r *rpcClient) connect(ctx context.Context) {
 }
 
 func (r *rpcClient) do(ctx context.Context, method string, args, result interface{}) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, method)
+	defer span.Finish()
+
 	waiter, err := r.Conn.DispatchCall(ctx, method, args)
 	if err != nil {
 		return fmt.Errorf("error dispatching %q call: %v", method, err)