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