Fix antctl trace-packet arguments missing issue

Fix the following error when running `antctl trace-packet`, which is
caused by missing arguments for ovs-appctl command.

```
syntax error at br-int (or the bridge name was omitted)
ovs-appctl: /var/run/openvswitch/ovs-vswitchd.103.ctl: server returned an error
```

Signed-off-by: Lan Luo <luola@vmware.com>

pkg/agent/apiserver/handlers/ovstracing/handler.go

@@ -356,7 +356,7 @@ func validateRequest(r *http.Request) (*request, *handlers.HandlerError) {
 	return &request, nil
 }
 
-// HandleFunc returns the function which can handle API requests to "/ovsflows".
+// HandleFunc returns the function which can handle API requests to "/ovstracing".
 func HandleFunc(aq querier.AgentQuerier) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		var traceReq *ovsctl.TracingRequest

pkg/ovs/ovsctl/appctl.go

@@ -38,6 +38,7 @@ func (r *ovsAppctlRunner) RunAppctlCmd(cmd string, needsBridge bool, args ...str
 	if needsBridge {
 		cmdArgs = append(cmdArgs, r.bridge)
 	}
+	cmdArgs = append(cmdArgs, args...)
 	ovsCmd := exec.CommandContext(context.TODO(), "ovs-appctl", cmdArgs...)
 	out, err := ovsCmd.CombinedOutput()
 	if err != nil {

test/e2e/antctl_test.go

@@ -67,6 +67,7 @@ func TestAntctl(t *testing.T) {
 
 	t.Run("testAntctlAgentLocalAccess", func(t *testing.T) {
 		testAntctlAgentLocalAccess(t, data)
+		testAntctlAgentTracePacket(t, data)
 	})
 	t.Run("testAntctlControllerRemoteAccess", func(t *testing.T) {
 		testAntctlControllerRemoteAccess(t, data, antctlServiceAccountName, antreaImage)
@@ -159,6 +160,30 @@ func testAntctlAgentLocalAccess(t *testing.T, data *TestData) {
 	}
 }
 
+// testAntctlAgentTracePacket ensures antctl trace-packet is runnable in an agent Pod.
+func testAntctlAgentTracePacket(t *testing.T, data *TestData) {
+	podName, err := data.getAntreaPodOnNode(controlPlaneNodeName())
+	if err != nil {
+		t.Fatalf("Error when getting antrea-agent pod name: %v", err)
+	}
+	var args []string
+	if testOptions.enableCoverage {
+		antctlCovArgs := antctlCoverageArgs("antctl-coverage", "")
+		args = append(antctlCovArgs, "trace-packet")
+	} else {
+		args = []string{"antctl", "trace-packet"}
+	}
+	t.Logf("args: %s", args)
+
+	cmd := strings.Join(args, " ")
+	t.Run(cmd, func(t *testing.T) {
+		stdout, stderr, err := runAntctl(podName, args, data)
+		if err != nil && !strings.Contains(stderr, "not enabled\n") {
+			t.Fatalf("Error when running `antctl trace-packet` from %s: %v\n%s", podName, err, antctlOutput(stdout, stderr))
+		}
+	})
+}
+
 func runAntctlPod(t *testing.T, data *TestData, podName string, antctlServiceAccountName string, antctlImage string, covDir string) {
 	b := NewPodBuilder(podName, data.testNamespace, antctlImage).WithServiceAccountName(antctlServiceAccountName).
 		WithContainerName("antctl").WithCommand([]string{"sleep", "3600"}).