service: support /var/lib/faasd/.docker/config.json

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

vendor/github.com/docker/docker-credential-helpers/client/command.go

@@ -0,0 +1,56 @@
+package client
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+)
+
+// Program is an interface to execute external programs.
+type Program interface {
+	Output() ([]byte, error)
+	Input(in io.Reader)
+}
+
+// ProgramFunc is a type of function that initializes programs based on arguments.
+type ProgramFunc func(args ...string) Program
+
+// NewShellProgramFunc creates programs that are executed in a Shell.
+func NewShellProgramFunc(name string) ProgramFunc {
+	return NewShellProgramFuncWithEnv(name, nil)
+}
+
+// NewShellProgramFuncWithEnv creates programs that are executed in a Shell with environment variables
+func NewShellProgramFuncWithEnv(name string, env *map[string]string) ProgramFunc {
+	return func(args ...string) Program {
+		return &Shell{cmd: createProgramCmdRedirectErr(name, args, env)}
+	}
+}
+
+func createProgramCmdRedirectErr(commandName string, args []string, env *map[string]string) *exec.Cmd {
+	programCmd := exec.Command(commandName, args...)
+	programCmd.Env = os.Environ()
+	if env != nil {
+		for k, v := range *env {
+			programCmd.Env = append(programCmd.Env, fmt.Sprintf("%s=%s", k, v))
+		}
+	}
+	programCmd.Stderr = os.Stderr
+	return programCmd
+}
+
+// Shell invokes shell commands to talk with a remote credentials helper.
+type Shell struct {
+	cmd *exec.Cmd
+}
+
+// Output returns responses from the remote credentials helper.
+func (s *Shell) Output() ([]byte, error) {
+	return s.cmd.Output()
+}
+
+// Input sets the input to send to a remote credentials helper.
+func (s *Shell) Input(in io.Reader) {
+	s.cmd.Stdin = in
+}