github.com/gunjan5/docker@v1.8.2/utils/git.go (about)

     1  package utils
     2  
     3  import (
     4  	"fmt"
     5  	"io/ioutil"
     6  	"net/http"
     7  	"net/url"
     8  	"os"
     9  	"os/exec"
    10  	"path/filepath"
    11  	"strings"
    12  
    13  	"github.com/docker/docker/pkg/symlink"
    14  	"github.com/docker/docker/pkg/urlutil"
    15  )
    16  
    17  // GitClone clones a repository into a newly created directory which
    18  // will be under "docker-build-git"
    19  func GitClone(remoteURL string) (string, error) {
    20  	if !urlutil.IsGitTransport(remoteURL) {
    21  		remoteURL = "https://" + remoteURL
    22  	}
    23  	root, err := ioutil.TempDir("", "docker-build-git")
    24  	if err != nil {
    25  		return "", err
    26  	}
    27  
    28  	u, err := url.Parse(remoteURL)
    29  	if err != nil {
    30  		return "", err
    31  	}
    32  
    33  	fragment := u.Fragment
    34  	clone := cloneArgs(u, root)
    35  
    36  	if output, err := git(clone...); err != nil {
    37  		return "", fmt.Errorf("Error trying to use git: %s (%s)", err, output)
    38  	}
    39  
    40  	return checkoutGit(fragment, root)
    41  }
    42  
    43  func cloneArgs(remoteURL *url.URL, root string) []string {
    44  	args := []string{"clone", "--recursive"}
    45  	shallow := len(remoteURL.Fragment) == 0
    46  
    47  	if shallow && strings.HasPrefix(remoteURL.Scheme, "http") {
    48  		res, err := http.Head(fmt.Sprintf("%s/info/refs?service=git-upload-pack", remoteURL))
    49  		if err != nil || res.Header.Get("Content-Type") != "application/x-git-upload-pack-advertisement" {
    50  			shallow = false
    51  		}
    52  	}
    53  
    54  	if shallow {
    55  		args = append(args, "--depth", "1")
    56  	}
    57  
    58  	if remoteURL.Fragment != "" {
    59  		remoteURL.Fragment = ""
    60  	}
    61  
    62  	return append(args, remoteURL.String(), root)
    63  }
    64  
    65  func checkoutGit(fragment, root string) (string, error) {
    66  	refAndDir := strings.SplitN(fragment, ":", 2)
    67  
    68  	if len(refAndDir[0]) != 0 {
    69  		if output, err := gitWithinDir(root, "checkout", refAndDir[0]); err != nil {
    70  			return "", fmt.Errorf("Error trying to use git: %s (%s)", err, output)
    71  		}
    72  	}
    73  
    74  	if len(refAndDir) > 1 && len(refAndDir[1]) != 0 {
    75  		newCtx, err := symlink.FollowSymlinkInScope(filepath.Join(root, refAndDir[1]), root)
    76  		if err != nil {
    77  			return "", fmt.Errorf("Error setting git context, %q not within git root: %s", refAndDir[1], err)
    78  		}
    79  
    80  		fi, err := os.Stat(newCtx)
    81  		if err != nil {
    82  			return "", err
    83  		}
    84  		if !fi.IsDir() {
    85  			return "", fmt.Errorf("Error setting git context, not a directory: %s", newCtx)
    86  		}
    87  		root = newCtx
    88  	}
    89  
    90  	return root, nil
    91  }
    92  
    93  func gitWithinDir(dir string, args ...string) ([]byte, error) {
    94  	a := []string{"--work-tree", dir, "--git-dir", filepath.Join(dir, ".git")}
    95  	return git(append(a, args...)...)
    96  }
    97  
    98  func git(args ...string) ([]byte, error) {
    99  	return exec.Command("git", args...).CombinedOutput()
   100  }