зеркало из https://github.com/microsoft/docker.git
83 строки
1.6 KiB
Go
83 строки
1.6 KiB
Go
package main
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import (
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"encoding/json"
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"errors"
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"github.com/dotcloud/docker/pkg/libcontainer"
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"io/ioutil"
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"log"
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"os"
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"strconv"
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)
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var (
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ErrUnsupported = errors.New("Unsupported method")
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ErrWrongArguments = errors.New("Wrong argument count")
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)
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func main() {
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container, err := loadContainer()
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if err != nil {
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log.Fatal(err)
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}
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argc := len(os.Args)
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if argc < 2 {
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log.Fatal(ErrWrongArguments)
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}
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switch os.Args[1] {
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case "exec": // this is executed outside of the namespace in the cwd
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var exitCode int
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nspid, err := readPid()
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if err != nil {
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if !os.IsNotExist(err) {
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log.Fatal(err)
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}
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}
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if nspid > 0 {
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exitCode, err = execinCommand(container, nspid, os.Args[2:])
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} else {
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exitCode, err = execCommand(container, os.Args[2:])
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}
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if err != nil {
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log.Fatal(err)
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}
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os.Exit(exitCode)
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case "init": // this is executed inside of the namespace to setup the container
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if argc < 3 {
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log.Fatal(ErrWrongArguments)
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}
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if err := initCommand(container, os.Args[2], os.Args[3:]); err != nil {
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log.Fatal(err)
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}
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default:
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log.Fatalf("command not supported for nsinit %s", os.Args[1])
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}
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}
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func loadContainer() (*libcontainer.Container, error) {
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f, err := os.Open("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.Container
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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 readPid() (int, error) {
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data, err := ioutil.ReadFile(".nspid")
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if err != nil {
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return -1, err
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}
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pid, err := strconv.Atoi(string(data))
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if err != nil {
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return -1, err
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}
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return pid, nil
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}
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