Print info for users to stderr when socket files are missing

[govpp.git] / adapter / socketclient / socketclient.go

diff --git a/adapter/socketclient/socketclient.go b/adapter/socketclient/socketclient.go
index 96f23e6..2144d24 100644 (file)
--- a/adapter/socketclient/socketclient.go
+++ b/adapter/socketclient/socketclient.go
@@ -40,6 +40,20 @@ const (
        DefaultSocketName = adapter.DefaultBinapiSocket
 )
 
+const socketMissing = `
+------------------------------------------------------------
+ VPP binary API socket file %s is missing!
+
+  - is VPP running with socket for binapi enabled?
+  - is the correct socket name configured?
+
+ To enable it add following section to your VPP config:
+   socksvr {
+     default
+   }
+------------------------------------------------------------
+`
+
 var (
        // DefaultConnectTimeout is default timeout for connecting
        DefaultConnectTimeout = time.Second * 3
@@ -165,7 +179,13 @@ func (c *vppClient) SetMsgCallback(cb adapter.MsgCallback) {
 }
 
 func (c *vppClient) Connect() error {
-       Log.Debugf("Connecting to: %v", c.sockAddr)
+       // check if socket exists
+       if _, err := os.Stat(c.sockAddr); os.IsNotExist(err) {
+               fmt.Fprintf(os.Stderr, socketMissing, c.sockAddr)
+               return fmt.Errorf("VPP API socket file %s does not exist", c.sockAddr)
+       } else if err != nil {
+               return fmt.Errorf("VPP API socket error: %v", err)
+       }
 
        if err := c.connect(c.sockAddr); err != nil {
                return err
@@ -212,12 +232,14 @@ func (c *vppClient) Disconnect() error {
 func (c *vppClient) connect(sockAddr string) error {
        addr := &net.UnixAddr{Name: sockAddr, Net: "unix"}
 
+       Log.Debugf("Connecting to: %v", c.sockAddr)
+
        conn, err := net.DialUnix("unix", nil, addr)
        if err != nil {
                // we try different type of socket for backwards compatbility with VPP<=19.04
                if strings.Contains(err.Error(), "wrong type for socket") {
                        addr.Net = "unixpacket"
-                       Log.Warnf("%s, retrying connect with type unixpacket", err)
+                       Log.Debugf("%s, retrying connect with type unixpacket", err)
                        conn, err = net.DialUnix("unixpacket", nil, addr)
                }
                if err != nil {