pkg/gitutils/gitutils.go

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package gitutils
import (
"fmt"
"io/ioutil"
"net/http"
"net/url"
"os"
"os/exec"
"path/filepath"
"strings"
"github.com/docker/docker/pkg/symlink"
"github.com/docker/docker/pkg/urlutil"
)
// Clone clones a repository into a newly created directory which
// will be under "docker-build-git"
func Clone(remoteURL string) (string, error) {
if !urlutil.IsGitTransport(remoteURL) {
remoteURL = "https://" + remoteURL
}
root, err := ioutil.TempDir("", "docker-build-git")
if err != nil {
return "", err
}
u, err := url.Parse(remoteURL)
if err != nil {
return "", err
}
fragment := u.Fragment
clone := cloneArgs(u, root)
if output, err := git(clone...); err != nil {
return "", fmt.Errorf("Error trying to use git: %s (%s)", err, output)
}
return checkoutGit(fragment, root)
}
func cloneArgs(remoteURL *url.URL, root string) []string {
args := []string{"clone", "--recursive"}
shallow := len(remoteURL.Fragment) == 0
if shallow && strings.HasPrefix(remoteURL.Scheme, "http") {
res, err := http.Head(fmt.Sprintf("%s/info/refs?service=git-upload-pack", remoteURL))
if err != nil || res.Header.Get("Content-Type") != "application/x-git-upload-pack-advertisement" {
shallow = false
}
}
if shallow {
args = append(args, "--depth", "1")
}
if remoteURL.Fragment != "" {
remoteURL.Fragment = ""
}
return append(args, remoteURL.String(), root)
}
func checkoutGit(fragment, root string) (string, error) {
refAndDir := strings.SplitN(fragment, ":", 2)
if len(refAndDir[0]) != 0 {
if output, err := gitWithinDir(root, "checkout", refAndDir[0]); err != nil {
return "", fmt.Errorf("Error trying to use git: %s (%s)", err, output)
}
}
if len(refAndDir) > 1 && len(refAndDir[1]) != 0 {
newCtx, err := symlink.FollowSymlinkInScope(filepath.Join(root, refAndDir[1]), root)
if err != nil {
return "", fmt.Errorf("Error setting git context, %q not within git root: %s", refAndDir[1], err)
}
fi, err := os.Stat(newCtx)
if err != nil {
return "", err
}
if !fi.IsDir() {
return "", fmt.Errorf("Error setting git context, not a directory: %s", newCtx)
}
root = newCtx
}
return root, nil
}
func gitWithinDir(dir string, args ...string) ([]byte, error) {
a := []string{"--work-tree", dir, "--git-dir", filepath.Join(dir, ".git")}
return git(append(a, args...)...)
}
func git(args ...string) ([]byte, error) {
return exec.Command("git", args...).CombinedOutput()
}