func rebuildImage(baseImage, imageName, buildDir string) error {
tmpImageName := fmt.Sprintf("image-%d", time.Now().Unix())
util.Debugf("building %q", tmpImageName)
cmd := exec.Command("docker", "build", "-t", tmpImageName, ".")
cmd.Dir = buildDir
if out, err := cmd.Output(); err != nil {
return fmt.Errorf("%s (%v)", string(out), err)
}
util.Debugf("removing image %q", baseImage)
if out, err := exec.Command("docker", "rmi", "-f", baseImage).Output(); err != nil {
return fmt.Errorf("%s (%v)", string(out), err)
}
util.Debugf("removing image %q", imageName)
if out, err := exec.Command("docker", "rmi", "-f", imageName).Output(); err != nil {
return fmt.Errorf("%s (%v)", string(out), err)
}
util.Debugf("tagging image %q as %q", tmpImageName, imageName)
if out, err := exec.Command("docker", "tag", tmpImageName, imageName).Output(); err != nil {
return fmt.Errorf("%s (%v)", string(out), err)
}
util.Debugf("removing image %q", tmpImageName)
if out, err := exec.Command("docker", "rmi", "-f", tmpImageName).Output(); err != nil {
return fmt.Errorf("%s (%v)", string(out), err)
}
return nil
}
func locateAndCopyOpenShiftBinary(dst string) error {
binaryPath, err := exec.LookPath("openshift")
if err != nil {
return err
}
util.Debugf("located openshift binary in %q", binaryPath)
if cpResult, err := exec.Command("cp", "-f", binaryPath, dst).Output(); err != nil {
return fmt.Errorf("%s: %v", string(cpResult), err)
}
util.Debugf("copied openshift binary to %q", dst)
return nil
}
func RebuildOpenShiftImage(name string) error {
tmpDir, err := ioutils.TempDir("", "otp-rebuild-")
if err != nil {
return err
}
defer os.RemoveAll(tmpDir)
if err := pullIfNotExists(name); err != nil {
return err
}
if err := locateAndCopyOpenShiftBinary(tmpDir); err != nil {
return err
}
layerID, err := findBinaryCopyLayer(name)
if err != nil {
return err
}
tmpBaseImageName := fmt.Sprintf("base-%d", time.Now().Unix())
util.Debugf("tagging image %q as %q", layerID, tmpBaseImageName)
if out, err := exec.Command("docker", "tag", layerID, tmpBaseImageName).Output(); err != nil {
return fmt.Errorf("%s (%v)", string(out), err)
}
if err := generateDockerfile(tmpBaseImageName, tmpDir); err != nil {
return err
}
if err := rebuildImage(tmpBaseImageName, name, tmpDir); err != nil {
return err
}
return nil
}
func findBinaryCopyLayer(name string) (string, error) {
util.Debugf("searching for the ADD openshift layer in %q image", name)
historyOut, err := exec.Command("docker", "history", "--no-trunc", name).CombinedOutput()
if err != nil {
return "", fmt.Errorf("%s: %v", string(historyOut), err)
}
result := ""
for _, line := range strings.Split(string(historyOut), "\n") {
if strings.Contains(line, "ADD") && strings.Contains(line, "/usr/bin/openshift") {
parts := strings.Split(line, " ")
if len(parts) > 0 {
result = strings.TrimSpace(parts[0])
}
util.Debugf("found ADD layer in %q", result)
}
}
if len(result) == 0 {
return "", fmt.Errorf("unable to detect COPY layer in %q", name)
}
return result, nil
}
func generateDockerfile(from, dstDir string) error {
content := []string{
fmt.Sprintf("FROM %s", from),
"ADD openshift /usr/bin/openshift",
}
outputFile := filepath.Join(dstDir, "Dockerfile")
err := ioutil.WriteFile(outputFile, []byte(strings.Join(content, "\n")+"\n"), 0666)
if err != nil {
return err
}
util.Debugf("written Dockerfile to %q", outputFile)
return nil
}