github.com/squaremo/docker@v1.3.2-0.20150516120342-42cfc9554972/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/urlutil"
    14  )
    15  
    16  func GitClone(remoteURL string) (string, error) {
    17  	if !urlutil.IsGitTransport(remoteURL) {
    18  		remoteURL = "https://" + remoteURL
    19  	}
    20  	root, err := ioutil.TempDir("", "docker-build-git")
    21  	if err != nil {
    22  		return "", err
    23  	}
    24  
    25  	u, err := url.Parse(remoteURL)
    26  	if err != nil {
    27  		return "", err
    28  	}
    29  
    30  	fragment := u.Fragment
    31  	clone := cloneArgs(u, root)
    32  
    33  	if output, err := git(clone...); err != nil {
    34  		return "", fmt.Errorf("Error trying to use git: %s (%s)", err, output)
    35  	}
    36  
    37  	return checkoutGit(fragment, root)
    38  }
    39  
    40  func cloneArgs(remoteURL *url.URL, root string) []string {
    41  	args := []string{"clone", "--recursive"}
    42  	shallow := len(remoteURL.Fragment) == 0
    43  
    44  	if shallow && strings.HasPrefix(remoteURL.Scheme, "http") {
    45  		res, err := http.Head(fmt.Sprintf("%s/info/refs?service=git-upload-pack", remoteURL))
    46  		if err != nil || res.Header.Get("Content-Type") != "application/x-git-upload-pack-advertisement" {
    47  			shallow = false
    48  		}
    49  	}
    50  
    51  	if shallow {
    52  		args = append(args, "--depth", "1")
    53  	}
    54  
    55  	if remoteURL.Fragment != "" {
    56  		remoteURL.Fragment = ""
    57  	}
    58  
    59  	return append(args, remoteURL.String(), root)
    60  }
    61  
    62  func checkoutGit(fragment, root string) (string, error) {
    63  	refAndDir := strings.SplitN(fragment, ":", 2)
    64  
    65  	if len(refAndDir[0]) != 0 {
    66  		if output, err := gitWithinDir(root, "checkout", refAndDir[0]); err != nil {
    67  			return "", fmt.Errorf("Error trying to use git: %s (%s)", err, output)
    68  		}
    69  	}
    70  
    71  	if len(refAndDir) > 1 && len(refAndDir[1]) != 0 {
    72  		newCtx := filepath.Join(root, refAndDir[1])
    73  		fi, err := os.Stat(newCtx)
    74  		if err != nil {
    75  			return "", err
    76  		}
    77  		if !fi.IsDir() {
    78  			return "", fmt.Errorf("Error setting git context, not a directory: %s", newCtx)
    79  		}
    80  		root = newCtx
    81  	}
    82  
    83  	return root, nil
    84  }
    85  
    86  func gitWithinDir(dir string, args ...string) ([]byte, error) {
    87  	a := []string{"--work-tree", dir, "--git-dir", filepath.Join(dir, ".git")}
    88  	return git(append(a, args...)...)
    89  }
    90  
    91  func git(args ...string) ([]byte, error) {
    92  	return exec.Command("git", args...).CombinedOutput()
    93  }