Add a moby build --pull option to force pulling images

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

src/cmd/moby/docker.go

@@ -0,0 +1,262 @@
+package main
+
+// We want to replace much of this with use of containerd tools
+// and also using the Docker API not shelling out
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os/exec"
+	"strings"
+)
+
+func dockerRun(args ...string) ([]byte, error) {
+	docker, err := exec.LookPath("docker")
+	if err != nil {
+		return []byte{}, errors.New("Docker does not seem to be installed")
+	}
+	args = append([]string{"run", "--rm"}, args...)
+	cmd := exec.Command(docker, args...)
+
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stdout, err := ioutil.ReadAll(stdoutPipe)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stderr, err := ioutil.ReadAll(stderrPipe)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return []byte{}, fmt.Errorf("%v: %s", err, stderr)
+	}
+
+	return stdout, nil
+}
+
+func dockerRunInput(input io.Reader, args ...string) ([]byte, error) {
+	docker, err := exec.LookPath("docker")
+	if err != nil {
+		return []byte{}, errors.New("Docker does not seem to be installed")
+	}
+	args = append([]string{"run", "--rm", "-i"}, args...)
+	cmd := exec.Command(docker, args...)
+	cmd.Stdin = input
+
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stdout, err := ioutil.ReadAll(stdoutPipe)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stderr, err := ioutil.ReadAll(stderrPipe)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return []byte{}, fmt.Errorf("%v: %s", err, stderr)
+	}
+
+	return stdout, nil
+}
+
+func dockerCreate(image string) (string, error) {
+	docker, err := exec.LookPath("docker")
+	if err != nil {
+		return "", errors.New("Docker does not seem to be installed")
+	}
+	// we do not ever run the container, so /dev/null is used as command
+	args := []string{"create", image, "/dev/null"}
+	cmd := exec.Command(docker, args...)
+
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return "", err
+	}
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return "", err
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return "", err
+	}
+
+	stdout, err := ioutil.ReadAll(stdoutPipe)
+	if err != nil {
+		return "", err
+	}
+
+	stderr, err := ioutil.ReadAll(stderrPipe)
+	if err != nil {
+		return "", err
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return "", fmt.Errorf("%s: %s", err, stderr)
+	}
+
+	container := strings.TrimSpace(string(stdout))
+	return container, nil
+}
+
+func dockerExport(container string) ([]byte, error) {
+	docker, err := exec.LookPath("docker")
+	if err != nil {
+		return []byte{}, errors.New("Docker does not seem to be installed")
+	}
+	args := []string{"export", container}
+	cmd := exec.Command(docker, args...)
+
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stdout, err := ioutil.ReadAll(stdoutPipe)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	stderr, err := ioutil.ReadAll(stderrPipe)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return []byte{}, fmt.Errorf("%v: %s", err, stderr)
+	}
+
+	return stdout, nil
+}
+
+func dockerRm(container string) error {
+	docker, err := exec.LookPath("docker")
+	if err != nil {
+		return errors.New("Docker does not seem to be installed")
+	}
+	args := []string{"rm", container}
+	cmd := exec.Command(docker, args...)
+
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return err
+	}
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return err
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return err
+	}
+
+	_, err = ioutil.ReadAll(stdoutPipe)
+	if err != nil {
+		return err
+	}
+
+	stderr, err := ioutil.ReadAll(stderrPipe)
+	if err != nil {
+		return err
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return fmt.Errorf("%s: %s", err, stderr)
+	}
+
+	return nil
+}
+
+func dockerPull(image string) error {
+	docker, err := exec.LookPath("docker")
+	if err != nil {
+		return errors.New("Docker does not seem to be installed")
+	}
+	args := []string{"pull", image}
+	cmd := exec.Command(docker, args...)
+
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return err
+	}
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return err
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return err
+	}
+
+	_, err = ioutil.ReadAll(stdoutPipe)
+	if err != nil {
+		return err
+	}
+
+	stderr, err := ioutil.ReadAll(stderrPipe)
+	if err != nil {
+		return err
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return fmt.Errorf("%s: %s", err, stderr)
+	}
+
+	return nil
+}