89 lines
2.4 KiB
Go
89 lines
2.4 KiB
Go
// Copyright 2016 CNI authors
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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 invoke
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import (
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"bytes"
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"context"
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"encoding/json"
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"fmt"
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"io"
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"os/exec"
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"strings"
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"time"
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"github.com/containernetworking/cni/pkg/types"
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)
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type RawExec struct {
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Stderr io.Writer
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}
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func (e *RawExec) ExecPlugin(ctx context.Context, pluginPath string, stdinData []byte, environ []string) ([]byte, error) {
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stdout := &bytes.Buffer{}
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stderr := &bytes.Buffer{}
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c := exec.CommandContext(ctx, pluginPath)
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c.Env = environ
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c.Stdin = bytes.NewBuffer(stdinData)
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c.Stdout = stdout
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c.Stderr = stderr
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// Retry the command on "text file busy" errors
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for i := 0; i <= 5; i++ {
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err := c.Run()
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// Command succeeded
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if err == nil {
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break
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}
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// If the plugin is currently about to be written, then we wait a
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// second and try it again
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if strings.Contains(err.Error(), "text file busy") {
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time.Sleep(time.Second)
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continue
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}
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// All other errors except than the busy text file
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return nil, e.pluginErr(err, stdout.Bytes(), stderr.Bytes())
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}
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// Copy stderr to caller's buffer in case plugin printed to both
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// stdout and stderr for some reason. Ignore failures as stderr is
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// only informational.
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if e.Stderr != nil && stderr.Len() > 0 {
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_, _ = stderr.WriteTo(e.Stderr)
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}
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return stdout.Bytes(), nil
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}
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func (e *RawExec) pluginErr(err error, stdout, stderr []byte) error {
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emsg := types.Error{}
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if len(stdout) == 0 {
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if len(stderr) == 0 {
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emsg.Msg = fmt.Sprintf("netplugin failed with no error message: %v", err)
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} else {
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emsg.Msg = fmt.Sprintf("netplugin failed: %q", string(stderr))
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}
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} else if perr := json.Unmarshal(stdout, &emsg); perr != nil {
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emsg.Msg = fmt.Sprintf("netplugin failed but error parsing its diagnostic message %q: %v", string(stdout), perr)
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}
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return &emsg
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}
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func (e *RawExec) FindInPath(plugin string, paths []string) (string, error) {
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return FindInPath(plugin, paths)
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}
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