Move pkg/gitutils to remotecontext/git

Signed-off-by: Daniel Nephin <dnephin@docker.com>
2017-06-02 16:54:50 -04:00
commit e907d54fe6
2 changed files with 302 additions and 0 deletions
@@ -0,0 +1,122 @@
+package git
+
+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"
+	"github.com/pkg/errors"
+)
+
+// 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
+	}
+
+	if out, err := gitWithinDir(root, "init"); err != nil {
+		return "", errors.Wrapf(err, "failed to init repo at %s: %s", root, out)
+	}
+
+	ref, subdir := getRefAndSubdir(u.Fragment)
+	fetch := fetchArgs(u, ref)
+
+	u.Fragment = ""
+
+	// Add origin remote for compatibility with previous implementation that
+	// used "git clone" and also to make sure local refs are created for branches
+	if out, err := gitWithinDir(root, "remote", "add", "origin", u.String()); err != nil {
+		return "", errors.Wrapf(err, "failed add origin repo at %s: %s", u.String(), out)
+	}
+
+	if output, err := gitWithinDir(root, fetch...); err != nil {
+		return "", errors.Wrapf(err, "error fetching: %s", output)
+	}
+
+	return checkoutGit(root, ref, subdir)
+}
+
+func getRefAndSubdir(fragment string) (ref string, subdir string) {
+	refAndDir := strings.SplitN(fragment, ":", 2)
+	ref = "master"
+	if len(refAndDir[0]) != 0 {
+		ref = refAndDir[0]
+	}
+	if len(refAndDir) > 1 && len(refAndDir[1]) != 0 {
+		subdir = refAndDir[1]
+	}
+	return
+}
+
+func fetchArgs(remoteURL *url.URL, ref string) []string {
+	args := []string{"fetch", "--recurse-submodules=yes"}
+	shallow := true
+
+	if 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")
+	}
+
+	return append(args, "origin", ref)
+}
+
+func checkoutGit(root, ref, subdir string) (string, error) {
+	// Try checking out by ref name first. This will work on branches and sets
+	// .git/HEAD to the current branch name
+	if output, err := gitWithinDir(root, "checkout", ref); err != nil {
+		// If checking out by branch name fails check out the last fetched ref
+		if _, err2 := gitWithinDir(root, "checkout", "FETCH_HEAD"); err2 != nil {
+			return "", errors.Wrapf(err, "error checking out %s: %s", ref, output)
+		}
+	}
+
+	if subdir != "" {
+		newCtx, err := symlink.FollowSymlinkInScope(filepath.Join(root, subdir), root)
+		if err != nil {
+			return "", errors.Wrapf(err, "error setting git context, %q not within git root", subdir)
+		}
+
+		fi, err := os.Stat(newCtx)
+		if err != nil {
+			return "", err
+		}
+		if !fi.IsDir() {
+			return "", errors.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()
+}
@@ -0,0 +1,180 @@
+package git
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCloneArgsSmartHttp(t *testing.T) {
+	mux := http.NewServeMux()
+	server := httptest.NewServer(mux)
+	serverURL, _ := url.Parse(server.URL)
+
+	serverURL.Path = "/repo.git"
+
+	mux.HandleFunc("/repo.git/info/refs", func(w http.ResponseWriter, r *http.Request) {
+		q := r.URL.Query().Get("service")
+		w.Header().Set("Content-Type", fmt.Sprintf("application/x-%s-advertisement", q))
+	})
+
+	args := fetchArgs(serverURL, "master")
+	exp := []string{"fetch", "--recurse-submodules=yes", "--depth", "1", "origin", "master"}
+	assert.Equal(t, exp, args)
+}
+
+func TestCloneArgsDumbHttp(t *testing.T) {
+	mux := http.NewServeMux()
+	server := httptest.NewServer(mux)
+	serverURL, _ := url.Parse(server.URL)
+
+	serverURL.Path = "/repo.git"
+
+	mux.HandleFunc("/repo.git/info/refs", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain")
+	})
+
+	args := fetchArgs(serverURL, "master")
+	exp := []string{"fetch", "--recurse-submodules=yes", "origin", "master"}
+	assert.Equal(t, exp, args)
+}
+
+func TestCloneArgsGit(t *testing.T) {
+	u, _ := url.Parse("git://github.com/docker/docker")
+	args := fetchArgs(u, "master")
+	exp := []string{"fetch", "--recurse-submodules=yes", "--depth", "1", "origin", "master"}
+	assert.Equal(t, exp, args)
+}
+
+func gitGetConfig(name string) string {
+	b, err := git([]string{"config", "--get", name}...)
+	if err != nil {
+		// since we are interested in empty or non empty string,
+		// we can safely ignore the err here.
+		return ""
+	}
+	return strings.TrimSpace(string(b))
+}
+
+func TestCheckoutGit(t *testing.T) {
+	root, err := ioutil.TempDir("", "docker-build-git-checkout")
+	require.NoError(t, err)
+	defer os.RemoveAll(root)
+
+	autocrlf := gitGetConfig("core.autocrlf")
+	if !(autocrlf == "true" || autocrlf == "false" ||
+		autocrlf == "input" || autocrlf == "") {
+		t.Logf("unknown core.autocrlf value: \"%s\"", autocrlf)
+	}
+	eol := "\n"
+	if autocrlf == "true" {
+		eol = "\r\n"
+	}
+
+	gitDir := filepath.Join(root, "repo")
+	_, err = git("init", gitDir)
+	require.NoError(t, err)
+
+	_, err = gitWithinDir(gitDir, "config", "user.email", "test@docker.com")
+	require.NoError(t, err)
+
+	_, err = gitWithinDir(gitDir, "config", "user.name", "Docker test")
+	require.NoError(t, err)
+
+	err = ioutil.WriteFile(filepath.Join(gitDir, "Dockerfile"), []byte("FROM scratch"), 0644)
+	require.NoError(t, err)
+
+	subDir := filepath.Join(gitDir, "subdir")
+	require.NoError(t, os.Mkdir(subDir, 0755))
+
+	err = ioutil.WriteFile(filepath.Join(subDir, "Dockerfile"), []byte("FROM scratch\nEXPOSE 5000"), 0644)
+	require.NoError(t, err)
+
+	if runtime.GOOS != "windows" {
+		if err = os.Symlink("../subdir", filepath.Join(gitDir, "parentlink")); err != nil {
+			t.Fatal(err)
+		}
+
+		if err = os.Symlink("/subdir", filepath.Join(gitDir, "absolutelink")); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	_, err = gitWithinDir(gitDir, "add", "-A")
+	require.NoError(t, err)
+
+	_, err = gitWithinDir(gitDir, "commit", "-am", "First commit")
+	require.NoError(t, err)
+
+	_, err = gitWithinDir(gitDir, "checkout", "-b", "test")
+	require.NoError(t, err)
+
+	err = ioutil.WriteFile(filepath.Join(gitDir, "Dockerfile"), []byte("FROM scratch\nEXPOSE 3000"), 0644)
+	require.NoError(t, err)
+
+	err = ioutil.WriteFile(filepath.Join(subDir, "Dockerfile"), []byte("FROM busybox\nEXPOSE 5000"), 0644)
+	require.NoError(t, err)
+
+	_, err = gitWithinDir(gitDir, "add", "-A")
+	require.NoError(t, err)
+
+	_, err = gitWithinDir(gitDir, "commit", "-am", "Branch commit")
+	require.NoError(t, err)
+
+	_, err = gitWithinDir(gitDir, "checkout", "master")
+	require.NoError(t, err)
+
+	type singleCase struct {
+		frag string
+		exp  string
+		fail bool
+	}
+
+	cases := []singleCase{
+		{"", "FROM scratch", false},
+		{"master", "FROM scratch", false},
+		{":subdir", "FROM scratch" + eol + "EXPOSE 5000", false},
+		{":nosubdir", "", true},   // missing directory error
+		{":Dockerfile", "", true}, // not a directory error
+		{"master:nosubdir", "", true},
+		{"master:subdir", "FROM scratch" + eol + "EXPOSE 5000", false},
+		{"master:../subdir", "", true},
+		{"test", "FROM scratch" + eol + "EXPOSE 3000", false},
+		{"test:", "FROM scratch" + eol + "EXPOSE 3000", false},
+		{"test:subdir", "FROM busybox" + eol + "EXPOSE 5000", false},
+	}
+
+	if runtime.GOOS != "windows" {
+		// Windows GIT (2.7.1 x64) does not support parentlink/absolutelink. Sample output below
+		// 	git --work-tree .\repo --git-dir .\repo\.git add -A
+		//	error: readlink("absolutelink"): Function not implemented
+		// 	error: unable to index file absolutelink
+		// 	fatal: adding files failed
+		cases = append(cases, singleCase{frag: "master:absolutelink", exp: "FROM scratch" + eol + "EXPOSE 5000", fail: false})
+		cases = append(cases, singleCase{frag: "master:parentlink", exp: "FROM scratch" + eol + "EXPOSE 5000", fail: false})
+	}
+
+	for _, c := range cases {
+		ref, subdir := getRefAndSubdir(c.frag)
+		r, err := checkoutGit(gitDir, ref, subdir)
+
+		if c.fail {
+			assert.Error(t, err)
+			continue
+		}
+
+		b, err := ioutil.ReadFile(filepath.Join(r, "Dockerfile"))
+		require.NoError(t, err)
+		assert.Equal(t, c.exp, string(b))
+	}
+}