cnitool: support capablity args

Signed-off-by: Pengfei Ni <feiskyer@gmail.com>

cnitool/cni.go

@@ -15,6 +15,7 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -25,6 +26,7 @@ import (
 const (
 	EnvCNIPath        = "CNI_PATH"
 	EnvNetDir         = "NETCONFPATH"
+	EnvCapabilityArgs = "CAP_ARGS"
 
 	DefaultNetDir = "/etc/cni/net.d"
 
@@ -47,6 +49,14 @@ func main() {
 		exit(err)
 	}
 
+	var capabilityArgs map[string]interface{}
+	args := os.Getenv(EnvCapabilityArgs)
+	if len(args) > 0 {
+		if err = json.Unmarshal([]byte(args), &capabilityArgs); err != nil {
+			exit(err)
+		}
+	}
+
 	netns := os.Args[3]
 
 	cninet := &libcni.CNIConfig{
@@ -57,6 +67,7 @@ func main() {
 		ContainerID:    "cni",
 		NetNS:          netns,
 		IfName:         "eth0",
+		CapabilityArgs: capabilityArgs,
 	}
 
 	switch os.Args[1] {