91 lines
1.6 KiB
Go
91 lines
1.6 KiB
Go
package main
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import (
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"encoding/json"
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"log"
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"os"
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"path/filepath"
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"github.com/codegangsta/cli"
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"github.com/docker/libcontainer"
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)
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// rFunc is a function registration for calling after an execin
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type rFunc struct {
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Usage string
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Action func(*libcontainer.Config, []string)
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}
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func loadConfig() (*libcontainer.Config, error) {
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f, err := os.Open(filepath.Join(dataPath, "container.json"))
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if err != nil {
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return nil, err
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}
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defer f.Close()
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var container *libcontainer.Config
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if err := json.NewDecoder(f).Decode(&container); err != nil {
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return nil, err
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}
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return container, nil
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}
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func openLog(name string) error {
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f, err := os.OpenFile(name, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0755)
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if err != nil {
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return err
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}
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log.SetOutput(f)
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return nil
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}
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func findUserArgs() []string {
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i := 0
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for _, a := range os.Args {
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i++
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if a == "--" {
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break
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}
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}
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return os.Args[i:]
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}
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// loadConfigFromFd loads a container's config from the sync pipe that is provided by
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// fd 3 when running a process
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func loadConfigFromFd() (*libcontainer.Config, error) {
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pipe := os.NewFile(3, "pipe")
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defer pipe.Close()
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var config *libcontainer.Config
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if err := json.NewDecoder(pipe).Decode(&config); err != nil {
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return nil, err
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}
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return config, nil
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}
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func preload(context *cli.Context) error {
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if logPath != "" {
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if err := openLog(logPath); err != nil {
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return err
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}
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}
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return nil
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}
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func runFunc(f *rFunc) {
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userArgs := findUserArgs()
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config, err := loadConfigFromFd()
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if err != nil {
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log.Fatalf("unable to receive config from sync pipe: %s", err)
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}
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f.Action(config, userArgs)
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}
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