Refactor initGitRepo to use libgit2 instead of go-git

Signed-off-by: Paulo Gomes <paulo.gomes@weave.works>

controllers/git_test.go

@@ -2,6 +2,7 @@ package controllers
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"path/filepath"
 	"testing"
@@ -9,7 +10,6 @@ import (
 
 	"github.com/go-git/go-billy/v5/memfs"
 	gogit "github.com/go-git/go-git/v5"
-	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/object"
 	"github.com/go-git/go-git/v5/storage/memory"
 	"github.com/go-logr/logr"
@@ -144,18 +144,11 @@ func TestPushRejected(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	tmp, err := os.MkdirTemp("", "gotest-imageauto-git")
-	if err != nil {
-		t.Fatal(err)
-	}
-	repoURL := gitServer.HTTPAddress() + "/appconfig.git"
-	repo, err := gogit.PlainClone(tmp, false, &gogit.CloneOptions{
-		URL:           repoURL,
-		ReferenceName: plumbing.NewBranchReferenceName("main"),
-	})
+	repoURL := gitServer.HTTPAddressWithCredentials() + "/appconfig.git"
+	repo, err := clone(repoURL, "origin", "main")
 
 	// This is here to guard against push in general being broken
-	err = push(context.TODO(), tmp, "main", repoAccess{
+	err = push(context.TODO(), repo.Workdir(), "main", repoAccess{
 		url:  repoURL,
 		auth: nil,
 	})
@@ -164,13 +157,13 @@ func TestPushRejected(t *testing.T) {
 	}
 
 	// This is not under test, but needed for the next bit
-	if err = switchBranch(repo, branch); err != nil {
+	if err = repo.SetHead(fmt.Sprintf("refs/heads/%s", branch)); err != nil {
 		t.Fatal(err)
 	}
 
 	// This is supposed to fail, because the hook rejects the branch
 	// pushed to.
-	err = push(context.TODO(), tmp, branch, repoAccess{
+	err = push(context.TODO(), repo.Workdir(), branch, repoAccess{
 		url:  repoURL,
 		auth: nil,
 	})

controllers/update_test.go

@@ -20,6 +20,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io/ioutil"
 	"math/rand"
 	"net/url"
 	"os"
@@ -28,6 +29,7 @@ import (
 	"strings"
 	"time"
 
+	securejoin "github.com/cyphar/filepath-securejoin"
 	"github.com/fluxcd/pkg/apis/acl"
 	git2go "github.com/libgit2/git2go/v33"
 	"golang.org/x/crypto/openpgp"
@@ -1329,57 +1331,170 @@ func commitInRepo(repoURL, branch, msg string, changeFiles func(path string)) {
 
 // Initialise a git server with a repo including the files in dir.
 func initGitRepo(gitServer *gittestserver.GitServer, fixture, branch, repositoryPath string) error {
-	fs := memfs.New()
-	repo, err := git.Init(memory.NewStorage(), fs)
+	workDir, err := securejoin.SecureJoin(gitServer.Root(), repositoryPath)
 	if err != nil {
 		return err
 	}
 
-	err = populateRepoFromFixture(repo, fixture)
+	repo, err := initGitRepoPlain(fixture, workDir)
 	if err != nil {
 		return err
 	}
 
-	working, err := repo.Worktree()
-	if err != nil {
-		return err
-	}
-	if err = working.Checkout(&git.CheckoutOptions{
-		Branch: plumbing.NewBranchReferenceName(branch),
-		Create: true,
-	}); err != nil {
-		return err
-	}
-
-	remote, err := repo.CreateRemote(&config.RemoteConfig{
-		Name: "origin",
-		URLs: []string{gitServer.HTTPAddressWithCredentials() + repositoryPath},
-	})
+	commitID, err := headCommit(repo)
 	if err != nil {
 		return err
 	}
 
-	err = remote.Push(&git.PushOptions{
-		RefSpecs: []config.RefSpec{
-			config.RefSpec(fmt.Sprintf("refs/heads/%s:refs/heads/%s", branch, branch)),
-		},
-	})
+	_, err = repo.CreateBranch(branch, commitID, false)
 	if err != nil {
 		return err
 	}
 
-	// Adhoc fix to a bug in which most clone operations during test fail.
-	// This started with the upgrade from libgit2 1.1.1 to 1.3.0, and
-	// requires further investigation as to why repositories created and
-	// amended by go-git stopped working for libgit2 clone operations.
-	repo2, err := git2go.OpenRepository(gitServer.Root() + repositoryPath)
+	return repo.Remotes.AddPush("origin", branchRefName(branch))
+}
+
+func initGitRepoPlain(fixture, repositoryPath string) (*git2go.Repository, error) {
+	repo, err := git2go.InitRepository(repositoryPath, false)
+	if err != nil {
+		return nil, err
+	}
+
+	err = copyDir(fixture, repositoryPath)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = commitWorkDir(repo, "main")
+	if err != nil {
+		return nil, err
+	}
+
+	return repo, nil
+}
+
+func headFromBranch(repo *git2go.Repository, branchName string) (*git2go.Commit, error) {
+	branch, err := repo.LookupBranch(branchName, git2go.BranchAll)
+	if err != nil {
+		return nil, err
+	}
+	defer branch.Free()
+
+	return repo.LookupCommit(branch.Reference.Target())
+}
+
+func commitWorkDir(repo *git2go.Repository, branchName string) (*git2go.Oid, error) {
+	var parentC []*git2go.Commit
+	head, err := headFromBranch(repo, branchName)
+	if err == nil {
+		defer head.Free()
+		parentC = append(parentC, head)
+	}
+
+	index, err := repo.Index()
+	if err != nil {
+		return nil, err
+	}
+	defer index.Free()
+
+	// add to index any files that are not within .git/
+	if err = filepath.Walk(repo.Workdir(),
+		func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+			rel, err := filepath.Rel(repo.Workdir(), path)
+			if err != nil {
+				return err
+			}
+			f, err := os.Stat(path)
+			if err != nil {
+				return err
+			}
+			if f.IsDir() || strings.HasPrefix(rel, ".git") || rel == "." {
+				return nil
+			}
+			if err := index.AddByPath(rel); err != nil {
+				return err
+			}
+			return nil
+		}); err != nil {
+		return nil, err
+	}
+
+	if err := index.Write(); err != nil {
+		return nil, err
+	}
+
+	treeID, err := index.WriteTree()
+	if err != nil {
+		return nil, err
+	}
+
+	tree, err := repo.LookupTree(treeID)
+	if err != nil {
+		return nil, err
+	}
+	defer tree.Free()
+
+	sig := mockSignature(time.Now())
+	c, err := repo.CreateCommit("HEAD", sig, sig, "Committing "+repo.Workdir(), tree, parentC...)
+	if err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+func copyDir(src string, dest string) error {
+	file, err := os.Stat(src)
 	if err != nil {
 		return err
 	}
-	defer repo2.Free()
-	_, err = commitFile(repo2, "branch", "init", time.Now())
+	if !file.IsDir() {
+		return fmt.Errorf("source %q must be a directory", file.Name())
+	}
 
-	return err
+	if err = os.MkdirAll(dest, 0o755); err != nil {
+		return err
+	}
+
+	files, err := ioutil.ReadDir(src)
+	if err != nil {
+		return err
+	}
+
+	for _, f := range files {
+		srcFile := filepath.Join(src, f.Name())
+		destFile := filepath.Join(dest, f.Name())
+
+		if f.IsDir() {
+			if err = copyDir(srcFile, destFile); err != nil {
+				return err
+			}
+		}
+
+		if !f.IsDir() {
+			// ignore symlinks
+			if f.Mode()&os.ModeSymlink == os.ModeSymlink {
+				continue
+			}
+
+			content, err := ioutil.ReadFile(srcFile)
+			if err != nil {
+				return err
+			}
+
+			if err = ioutil.WriteFile(destFile, content, 0o755); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func branchRefName(branch string) string {
+	return fmt.Sprintf("refs/heads/%s:refs/heads/%s", branch, branch)
 }
 
 func checkoutBranch(repo *git.Repository, branch string) error {
@@ -1509,3 +1624,26 @@ func headCommit(repo *git2go.Repository) (*git2go.Commit, error) {
 	}
 	return c, nil
 }
+
+func clone(repoURL, remoteName, branchName string) (*git2go.Repository, error) {
+	dir, err := os.MkdirTemp("", "iac-clone-*")
+	if err != nil {
+		return nil, err
+	}
+	opts := &git2go.CloneOptions{
+		Bare:           false,
+		CheckoutBranch: branchName,
+		CheckoutOptions: git2go.CheckoutOptions{
+			Strategy: git2go.CheckoutForce,
+		},
+		FetchOptions: git2go.FetchOptions{
+			RemoteCallbacks: git2go.RemoteCallbacks{
+				CertificateCheckCallback: func(cert *git2go.Certificate, valid bool, hostname string) error {
+					return nil
+				},
+			},
+		},
+	}
+
+	return git2go.Clone(repoURL, dir, opts)
+}