Eugene Yakubovich c24708ff62 Add plugin code
This adds basic plugins.
"main" types: veth, bridge, macvlan
"ipam" type: host-local

The code has been ported over from github.com/coreos/rkt project
and adapted to fit the CNI spec.
2015-04-27 14:14:29 -07:00

137 lines
3.4 KiB
Go

// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package plugin
import (
"bytes"
"encoding/json"
"fmt"
"os"
"os/exec"
"path/filepath"
"strings"
"github.com/appc/cni/Godeps/_workspace/src/github.com/vishvananda/netlink"
"github.com/appc/cni/pkg/ip"
)
// Find returns the full path of the plugin by searching in CNI_PATH
func Find(plugin string) string {
paths := strings.Split(os.Getenv("CNI_PATH"), ":")
for _, p := range paths {
fullname := filepath.Join(p, plugin)
if fi, err := os.Stat(fullname); err == nil && fi.Mode().IsRegular() {
return fullname
}
}
return ""
}
// ExecAdd executes IPAM plugin, assuming CNI_COMMAND == ADD.
// Parses and returns resulting IPConfig
func ExecAdd(plugin string, netconf []byte) (*Result, error) {
if os.Getenv("CNI_COMMAND") != "ADD" {
return nil, fmt.Errorf("CNI_COMMAND is not ADD")
}
pluginPath := Find(plugin)
if pluginPath == "" {
return nil, fmt.Errorf("could not find %q plugin", plugin)
}
stdout := &bytes.Buffer{}
c := exec.Cmd{
Path: pluginPath,
Args: []string{pluginPath},
Stdin: bytes.NewBuffer(netconf),
Stdout: stdout,
Stderr: os.Stderr,
}
if err := c.Run(); err != nil {
return nil, err
}
res := &Result{}
err := json.Unmarshal(stdout.Bytes(), res)
return res, err
}
// ExecDel executes IPAM plugin, assuming CNI_COMMAND == DEL.
func ExecDel(plugin string, netconf []byte) error {
if os.Getenv("CNI_COMMAND") != "DEL" {
return fmt.Errorf("CNI_COMMAND is not DEL")
}
pluginPath := Find(plugin)
if pluginPath == "" {
return fmt.Errorf("could not find %q plugin", plugin)
}
c := exec.Cmd{
Path: pluginPath,
Args: []string{pluginPath},
Stdin: bytes.NewBuffer(netconf),
Stderr: os.Stderr,
}
return c.Run()
}
// ConfigureIface takes the result of IPAM plugin and
// applies to the ifName interface
func ConfigureIface(ifName string, res *Result) error {
link, err := netlink.LinkByName(ifName)
if err != nil {
return fmt.Errorf("failed to lookup %q: %v", ifName, err)
}
if err := netlink.LinkSetUp(link); err != nil {
return fmt.Errorf("failed too set %q UP: %v", ifName, err)
}
// TODO(eyakubovich): IPv6
addr := &netlink.Addr{IPNet: &res.IP4.IP, Label: ""}
if err = netlink.AddrAdd(link, addr); err != nil {
return fmt.Errorf("failed to add IP addr to %q: %v", ifName, err)
}
for _, r := range res.IP4.Routes {
gw := r.GW
if gw == nil {
gw = res.IP4.Gateway
}
if err = ip.AddRoute(&r.Dst, gw, link); err != nil {
// we skip over duplicate routes as we assume the first one wins
if !os.IsExist(err) {
return fmt.Errorf("failed to add route '%v via %v dev %v': %v", r.Dst, gw, ifName, err)
}
}
}
return nil
}
// PrintResult writes out prettified Result to stdout
func PrintResult(res *Result) error {
data, err := json.MarshalIndent(res, "", " ")
if err != nil {
return err
}
_, err = os.Stdout.Write(data)
return err
}