Use existing VPP instance if given

Signed-off-by: Vladimir Popov <[email protected]>

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/antonfisher/nested-logrus-formatter v1.3.0
 	github.com/edwarnicke/debug v1.0.0
 	github.com/edwarnicke/grpcfd v0.1.0
-	github.com/edwarnicke/vpphelper v0.0.0-20210225052320-b4f1f1aff45d
+	github.com/edwarnicke/vpphelper v0.0.0-20210512223648-f914b171f679
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/networkservicemesh/api v1.0.1-0.20210811070028-10403c0f20c8
 	github.com/networkservicemesh/sdk v0.5.1-0.20210823074050-b1370083e4e1

go.sum

@@ -45,8 +45,8 @@ github.com/edwarnicke/log v1.0.0/go.mod h1:eWsQQlQ0IU5wHlJvyXFH3dS8s2g9GzN7JnXod
 github.com/edwarnicke/serialize v0.0.0-20200705214914-ebc43080eecf/go.mod h1:XvbCO/QGsl3X8RzjBMoRpkm54FIAZH5ChK2j+aox7pw=
 github.com/edwarnicke/serialize v1.0.7 h1:geX8vmyu8Ij2S5fFIXjy9gBDkKxXnrMIzMoDvV0Ddac=
 github.com/edwarnicke/serialize v1.0.7/go.mod h1:y79KgU2P7ALH/4j37uTSIdNavHFNttqN7pzO6Y8B2aw=
-github.com/edwarnicke/vpphelper v0.0.0-20210225052320-b4f1f1aff45d h1:Okg1uazbTBFvNTrWP5AbTLgG/xMsnZNIobxJYpyvyK8=
-github.com/edwarnicke/vpphelper v0.0.0-20210225052320-b4f1f1aff45d/go.mod h1:2KXgJqOUUCh9S4Zs2jAycQLqAcRGge3q+GXV2rN55ZQ=
+github.com/edwarnicke/vpphelper v0.0.0-20210512223648-f914b171f679 h1:TQGpOyiM1EZtGzKN5vwN5RLHc0Mskk9uh+aNsdynb1k=
+github.com/edwarnicke/vpphelper v0.0.0-20210512223648-f914b171f679/go.mod h1:2KXgJqOUUCh9S4Zs2jAycQLqAcRGge3q+GXV2rN55ZQ=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=

main.go

@@ -53,14 +53,15 @@ import (
 	"github.com/networkservicemesh/sdk/pkg/tools/token"
 )
 
-// Config - configuration for cmd-forwarder-vpp
+// Config - configuration for cmd-nsc-vpp
 type Config struct {
 	Name             string        `default:"cmd-nsc-vpp" desc:"Name of Endpoint"`
 	DialTimeout      time.Duration `default:"5s" desc:"timeout to dial NSMgr" split_words:"true"`
 	RequestTimeout   time.Duration `default:"15s" desc:"timeout to request NSE" split_words:"true"`
 	ConnectTo        url.URL       `default:"unix:///var/lib/networkservicemesh/nsm.io.sock" desc:"url to connect to" split_words:"true"`
 	MaxTokenLifetime time.Duration `default:"10m" desc:"maximum lifetime of tokens" split_words:"true"`
 	NetworkServices  []url.URL     `default:"" desc:"A list of Network Service Requests" split_words:"true"`
+	VppAPISocket     string        `default:"" desc:"filename of socket to connect to existing VPP instance. If empty a VPP instance is run in client" split_words:"true"`
 }
 
 func main() {
@@ -115,8 +116,17 @@ func main() {
 	// ********************************************************************************
 	now = time.Now()
 
-	vppConn, vppErrCh := vpphelper.StartAndDialContext(ctx)
-	exitOnErrCh(ctx, cancel, vppErrCh)
+	var vppConn vpphelper.Connection
+	var vppErrCh <-chan error
+	if config.VppAPISocket != "" { // If we have a VppAPISocket, use that
+		vppConn = vpphelper.DialContext(ctx, config.VppAPISocket)
+		errCh := make(chan error)
+		close(errCh)
+		vppErrCh = errCh
+	} else { // If we don't have a VPPAPISocket, start VPP and use that
+		vppConn, vppErrCh = vpphelper.StartAndDialContext(ctx)
+		exitOnErrCh(ctx, cancel, vppErrCh)
+	}
 
 	defer func() {
 		cancel()