add test for 'subnet' flag

test/integration/kic_custom_network_test.go

@@ -75,7 +75,7 @@ func TestKicExistingNetwork(t *testing.T) {
 	}
 	// create custom network
 	networkName := "existing-network"
-	if _, err := oci.CreateNetwork(oci.Docker, networkName); err != nil {
+	if _, err := oci.CreateNetwork(oci.Docker, networkName, ""); err != nil {
 		t.Fatalf("error creating network: %v", err)
 	}
 	defer func() {
@@ -97,6 +97,27 @@ func TestKicExistingNetwork(t *testing.T) {
 	}
 }
 
+// TestKicCustomSubnet verifies the docker/podman driver works with a custom subnet
+func TestKicCustomSubnet(t *testing.T) {
+	if !KicDriver() {
+		t.Skip("only runs with docker/podman driver")
+	}
+
+	profile := UniqueProfileName("custom-subnet")
+	ctx, cancel := context.WithTimeout(context.Background(), Minutes(5))
+	defer Cleanup(t, profile, cancel)
+
+	subnet := "192.168.60.0/24"
+	startArgs := []string{"start", "-p", profile, fmt.Sprintf("--subnet=%s", subnet)}
+	c := exec.CommandContext(ctx, Target(), startArgs...)
+	rr, err := Run(t, c)
+	if err != nil {
+		t.Fatalf("%v failed: %v\n%v", rr.Command(), err, rr.Output())
+	}
+
+	verifySubnet(ctx, t, profile, subnet)
+}
+
 func verifyNetworkExists(ctx context.Context, t *testing.T, networkName string) {
 	c := exec.CommandContext(ctx, "docker", "network", "ls", "--format", "{{.Name}}")
 	rr, err := Run(t, c)
@@ -107,3 +128,15 @@ func verifyNetworkExists(ctx context.Context, t *testing.T, networkName string)
 		t.Fatalf("%s network is not listed by [%v]: %v", networkName, c.Args, output)
 	}
 }
+
+func verifySubnet(ctx context.Context, t *testing.T, network, subnet string) {
+	c := exec.CommandContext(ctx, "docker", "network", "inspect", network, "--format", "{{(index .IPAM.Config 0).Subnet}}")
+	rr, err := Run(t, c)
+	if err != nil {
+		t.Fatalf("%v failed: %v\n%v", rr.Command(), err, rr.Output())
+	}
+
+	if output := strings.TrimSpace(rr.Output()); !strings.Contains(output, subnet) {
+		t.Fatalf("%s subnet not match to %v", subnet, output)
+	}
+}