78 lines
1.8 KiB
Go
78 lines
1.8 KiB
Go
package main
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import (
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"fmt"
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"log"
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"os"
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"os/exec"
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"os/signal"
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"github.com/codegangsta/cli"
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"github.com/docker/libcontainer"
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"github.com/docker/libcontainer/namespaces"
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)
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var execCommand = cli.Command{
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Name: "exec",
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Usage: "execute a new command inside a container",
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Action: execAction,
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}
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func execAction(context *cli.Context) {
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var exitCode int
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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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state, err := libcontainer.GetState(dataPath)
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if err != nil && !os.IsNotExist(err) {
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log.Fatalf("unable to read state.json: %s", err)
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}
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if state != nil {
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err = namespaces.ExecIn(container, state, []string(context.Args()))
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} else {
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term := namespaces.NewTerminal(os.Stdin, os.Stdout, os.Stderr, container.Tty)
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exitCode, err = startContainer(container, term, dataPath, []string(context.Args()))
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}
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if err != nil {
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log.Fatalf("failed to exec: %s", err)
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}
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os.Exit(exitCode)
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}
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// startContainer starts the container. Returns the exit status or -1 and an
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// error.
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//
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// Signals sent to the current process will be forwarded to container.
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func startContainer(container *libcontainer.Config, term namespaces.Terminal, dataPath string, args []string) (int, error) {
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var (
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cmd *exec.Cmd
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sigc = make(chan os.Signal, 10)
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)
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signal.Notify(sigc)
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createCommand := func(container *libcontainer.Config, console, rootfs, dataPath, init string, pipe *os.File, args []string) *exec.Cmd {
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cmd = namespaces.DefaultCreateCommand(container, console, rootfs, dataPath, init, pipe, args)
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if logPath != "" {
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cmd.Env = append(cmd.Env, fmt.Sprintf("log=%s", logPath))
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}
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return cmd
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}
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startCallback := func() {
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go func() {
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for sig := range sigc {
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cmd.Process.Signal(sig)
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}
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}()
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}
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return namespaces.Exec(container, term, "", dataPath, args, createCommand, startCallback)
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}
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