Add make target to enable debugger during test run

Signed-off-by: Yevhen Vydolob <[email protected]>

DEVELOPMENT.md

@@ -0,0 +1,46 @@
+### Debugging test
+
+#### MacOS
+
+You could debug test with [Delve](https://github.com/go-delve/delve) debugger.
+Run:
+```shell
+make test-mac-debug
+```
+This command will run build `gvisor` binary with debugger enabled.
+
+>Note: By default it would use `--continue` `dlv` option to not pause `gvisor` execution on start, if debugger is not connected.
+> To pause `gvisor` execution until debugger is connected just remove `"--continue"` parameter from this [line](./test-vfkit/vfkit_suite_test.go#L93) 
+
+And debug server with `2345` port, you could use any `delve` client to interact with debugger
+
+##### CLI Example
+
+Connect to debugger server with:
+```shell
+dlv connect :2345
+```
+Example of usage:
+```shell
+Type 'help' for list of commands.
+(dlv) break main.main
+Breakpoint 1 set at 0xe735776 for main.main() ./work/redhat/gvisor-tap-vsock/cmd/gvproxy/main.go:59
+(dlv) continue
+> [Breakpoint 1] main.main() ./work/redhat/gvisor-tap-vsock/cmd/gvproxy/main.go:59 (hits goroutine(1):1 total:1) (PC: 0xe735776)
+    54:         hostIP      = "192.168.127.254"
+    55:         host        = "host"
+    56:         gateway     = "gateway"
+    57: )
+    58:
+=>  59: func main() {
+    60:         version := types.NewVersion("gvproxy")
+    61:         version.AddFlag()
+    62:         flag.Var(&endpoints, "listen", "control endpoint")
+    63:         flag.BoolVar(&debug, "debug", false, "Print debug info")
+    64:         flag.IntVar(&mtu, "mtu", 1500, "Set the MTU")
+```
+More info about CLI client [here](https://github.com/go-delve/delve/blob/master/Documentation/cli/README.md)
+
+#### Editor integration
+
+For available editor integration look [there](https://github.com/go-delve/delve/blob/master/Documentation/EditorIntegration.md)

Makefile

@@ -78,3 +78,8 @@ test-qemu: gvproxy test-companion
 .PHONY: test-mac
 test-mac: gvproxy
 	go test -timeout 20m  -v ./test-vfkit
+
+.PHONY: test-mac-debug
+test-mac-debug:
+	go test -timeout 20m  -v ./test-vfkit --debug
+	rm -f ./test-vfkit/__debug_bin*

README.md

@@ -207,3 +207,7 @@ This is the same behaviour as [slirp](https://wiki.qemu.org/index.php/Documentat
 2. Each time, a client sends a http request, the process creates and sends the appropriate Ethernet packets to the VM.
 3. The tap device receives the packets and injects them in the kernel.
 4. The http server receives the request and send back the response.
+
+### Development
+
+[Development](./DEVELOPMENT.md)

test-vfkit/vfkit_suite_test.go

@@ -48,6 +48,8 @@ var (
 	ignFile        string
 )
 
+var debugEnabled = flag.Bool("debug", false, "enable debugger")
+
 func init() {
 	flag.StringVar(&tmpDir, "tmpDir", "../tmp", "temporary working directory")
 	flag.StringVar(&binDir, "bin", "../bin", "directory with compiled binaries")
@@ -86,9 +88,17 @@ var _ = ginkgo.BeforeSuite(func() {
 outer:
 	for panics := 0; ; panics++ {
 		_ = os.Remove(sock)
-
-		// #nosec
-		host = exec.Command(filepath.Join(binDir, "gvproxy"), fmt.Sprintf("--ssh-port=%d", sshPort), fmt.Sprintf("--listen=unix://%s", sock), fmt.Sprintf("--listen-vfkit=unixgram://%s", vfkitSock))
+		_ = os.Remove(vfkitSock)
+
+		gvproxyArgs := []string{fmt.Sprintf("--ssh-port=%d", sshPort), fmt.Sprintf("--listen=unix://%s", sock), fmt.Sprintf("--listen-vfkit=unixgram://%s", vfkitSock)}
+		if *debugEnabled {
+			dlvArgs := []string{"debug", "--headless", "--listen=:2345", "--continue", "--api-version=2", "--accept-multiclient", "../cmd/gvproxy", "--"}
+			dlvArgs = append(dlvArgs, gvproxyArgs...)
+			host = exec.Command("dlv", dlvArgs...)
+		} else {
+			// #nosec
+			host = exec.Command(filepath.Join(binDir, "gvproxy"), gvproxyArgs...)
+		}
 
 		host.Stderr = os.Stderr
 		host.Stdout = os.Stdout
@@ -103,7 +113,7 @@ outer:
 		for {
 			_, err := os.Stat(sock)
 			if os.IsNotExist(err) {
-				log.Info("waiting for socket")
+				log.Info("waiting for vfkit-api socket")
 				time.Sleep(100 * time.Millisecond)
 				continue
 			}