add grpc server support

providers/grpcs/config.go

@@ -0,0 +1,30 @@
+package grpcs
+
+import (
+	"fmt"
+)
+
+const DefaultPrefix = "Grpc"
+
+type Config struct {
+	Host *string
+	Port uint
+	Tls  *Tls
+}
+
+type Tls struct {
+	CA   string
+	Cert string
+	Key  string
+}
+
+func (h *Config) Address() string {
+	if h.Host == nil {
+		return h.PortString()
+	}
+	return fmt.Sprintf("%s:%d", *h.Host, h.Port)
+}
+
+func (h *Config) PortString() string {
+	return fmt.Sprintf(":%d", h.Port)
+}