DockerCLI/daemon_unix.go

80 lines
1.7 KiB
Go

// +build daemon
package main
import (
"fmt"
"os"
"os/exec"
"path/filepath"
"syscall"
"github.com/spf13/cobra"
)
const daemonBinary = "dockerd"
func newDaemonCommand() *cobra.Command {
cmd := &cobra.Command{
Use: "daemon",
Hidden: true,
Args: cobra.ArbitraryArgs,
DisableFlagParsing: true,
RunE: func(cmd *cobra.Command, args []string) error {
return runDaemon()
},
Deprecated: "and will be removed in Docker 1.16. Please run `dockerd` directly.",
}
cmd.SetHelpFunc(helpFunc)
return cmd
}
// CmdDaemon execs dockerd with the same flags
func runDaemon() error {
// Use os.Args[1:] so that "global" args are passed to dockerd
return execDaemon(stripDaemonArg(os.Args[1:]))
}
func execDaemon(args []string) error {
binaryPath, err := findDaemonBinary()
if err != nil {
return err
}
return syscall.Exec(
binaryPath,
append([]string{daemonBinary}, args...),
os.Environ())
}
func helpFunc(cmd *cobra.Command, args []string) {
if err := execDaemon([]string{"--help"}); err != nil {
fmt.Fprintf(os.Stderr, "%s\n", err.Error())
}
}
// findDaemonBinary looks for the path to the dockerd binary starting with
// the directory of the current executable (if one exists) and followed by $PATH
func findDaemonBinary() (string, error) {
execDirname := filepath.Dir(os.Args[0])
if execDirname != "" {
binaryPath := filepath.Join(execDirname, daemonBinary)
if _, err := os.Stat(binaryPath); err == nil {
return binaryPath, nil
}
}
return exec.LookPath(daemonBinary)
}
// stripDaemonArg removes the `daemon` argument from the list
func stripDaemonArg(args []string) []string {
for i, arg := range args {
if arg == "daemon" {
return append(args[:i], args[i+1:]...)
}
}
return args
}