Use go-git for Git operations

github.com/go-git/go-git is actively maintained and used in several other Arduino tooling projects. It provides all the
functionality needed for this application without the difficulties associated wih authentication in order to access a
dependency hosted in a private repository, as was the case with the github.com/arduino/arduino-modules/git package it
replaces.

Author: per1234

README.md

@@ -6,25 +6,10 @@ go get github.com/google/go-github/github
 go get github.com/vaughan0/go-ini
 go get github.com/blang/semver
 go get github.com/stretchr/testify
-go get github.com/arduino/arduino-modules/git
 
 go build arduino.cc/repository/libraries-repository-engine
 ```
 
-You may want to setup git to allow "go get" from private repos, in this case you must
-generate a personal access token from github that grants "repo access" permissions and do:
-
-```
-git config --global url."https://YOUR_ACCESS_TOKEN:x-oauth-basic@github.com/".insteadOf "https://github.com/"
-```
-
-the configuration will be saved inside `~/.gitconfig` as:
-
-```
-...
-[url "https://YOUR_ACCESS_TOKEN:x-oauth-basic@github.com/"]
-	insteadOf = https://github.com/
-...
 ```
 
 TDD

Taskfile.yml

@@ -8,7 +8,6 @@ tasks:
   go:deps:
     desc: Install dependencies
     cmds:
-      - go get github.com/arduino/arduino-modules/git
       - go get github.com/arduino/golang-concurrent-workers
       - go get github.com/blang/semver
       - go get github.com/google/go-github/github

src/arduino.cc/repository/libraries-repository-engine/sync_libraries.go

@@ -12,8 +12,9 @@ import (
 	"arduino.cc/repository/libraries"
 	"arduino.cc/repository/libraries/db"
 	"arduino.cc/repository/libraries/hash"
-	"github.com/arduino/arduino-modules/git"
 	cc "github.com/arduino/golang-concurrent-workers"
+	"github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/plumbing"
 )
 
 type Config struct {
@@ -202,13 +203,19 @@ func syncLibrary(logger *log.Logger, repoMetadata *libraries.Repo, libraryDb *db
 	}
 
 	// Retrieve the list of git-tags
-	tags, err := repo.ListTags()
+	tags, err := repo.Repository.Tags()
 	if err != nil {
 		logger.Printf("Error retrieving git-tags: %s", err)
 		return
 	}
 
-	for _, tag := range tags {
+	for {
+		tag, err := tags.Next()
+		if err != nil {
+			// Reached end of tags
+			break
+		}
+
 		// Sync the library release for each git-tag
 		err = syncLibraryTaggedRelease(logger, repo, tag, repoMetadata, libraryDb)
 		if err != nil {
@@ -217,11 +224,16 @@ func syncLibrary(logger *log.Logger, repoMetadata *libraries.Repo, libraryDb *db
 	}
 }
 
-func syncLibraryTaggedRelease(logger *log.Logger, repo *git.Repository, tag string, repoMeta *libraries.Repo, libraryDb *db.DB) error {
+func syncLibraryTaggedRelease(logger *log.Logger, repo *libraries.Repository, tag *plumbing.Reference, repoMeta *libraries.Repo, libraryDb *db.DB) error {
 	// Checkout desired tag
-	logger.Printf("Checking out tag: %s", tag)
-	if out, err := repo.CheckoutTagWithOutput(tag); err != nil {
-		logger.Printf("git output: %s", out)
+	logger.Printf("Checking out tag: %s", tag.Name())
+
+	repoTree, err := repo.Repository.Worktree()
+	if err != nil {
+		return err
+	}
+
+	if err = repoTree.Checkout(&git.CheckoutOptions{Hash: tag.Hash()}); err != nil {
 		return fmt.Errorf("Error checking out repo: %s", err)
 	}
 

src/arduino.cc/repository/libraries/git_integration_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"arduino.cc/repository/libraries/db"
+	"github.com/go-git/go-git/v5"
 	"github.com/stretchr/testify/require"
 )
 
@@ -33,11 +34,14 @@ func TestUpdateLibraryJson(t *testing.T) {
 
 		defer os.RemoveAll(r.FolderPath)
 
-		tags, err := r.ListTags()
+		tags, err := r.Repository.Tags()
+		require.NoError(t, err)
+		tag, err := tags.Next()
 		require.NoError(t, err)
-		require.NotEmpty(t, tags)
 
-		err = r.CheckoutTag(tags[0])
+		repoTree, err := r.Repository.Worktree()
+		require.NoError(t, err)
+		err = repoTree.Checkout(&git.CheckoutOptions{Hash: tag.Hash()})
 		require.NoError(t, err)
 
 		library, err := GenerateLibraryFromRepo(r)

src/arduino.cc/repository/libraries/repoclone.go

@@ -12,38 +12,59 @@ import (
 	"fmt"
 
 	"arduino.cc/repository/libraries/metadata"
-	"github.com/arduino/arduino-modules/git"
+	"github.com/go-git/go-git/v5"
 )
 
-func CloneOrFetch(repoMeta *Repo, folderName string) (*git.Repository, error) {
-	var repo *git.Repository
+// Repository represents a Git repository located on the filesystem.
+type Repository struct {
+	Repository *git.Repository
+	FolderPath string
+	URL        string
+}
+
+func CloneOrFetch(repoMeta *Repo, folderName string) (*Repository, error) {
+	repo := Repository{
+		FolderPath: folderName,
+		URL:        repoMeta.Url,
+	}
+
 	if _, err := os.Stat(folderName); os.IsNotExist(err) {
-		repo, err = git.Clone(repoMeta.Url, folderName)
+		repo.Repository, err = git.PlainClone(folderName, false, &git.CloneOptions{URL: repoMeta.Url})
 		if err != nil {
 			return nil, err
 		}
 	} else {
-		repo = &git.Repository{FolderPath: folderName, URL: repoMeta.Url}
+		repo.Repository, err = git.PlainOpen(folderName)
+		if err != nil {
+			return nil, err
+		}
 	}
 
-	tags, err := repo.ListTags()
+	tags, err := repo.Repository.Tags()
 	if err != nil {
 		return nil, err
 	}
-	for _, tag := range tags {
-		if err = repo.RemoveTag(tag); err != nil {
+
+	for {
+		tag, err := tags.Next()
+		if err != nil {
+			// Reached end of tags
+			break
+		}
+
+		if err = repo.Repository.DeleteTag(strings.TrimPrefix(tag.Name().String(), "refs/tags/")); err != nil {
 			return nil, err
 		}
 	}
 
-	if err = repo.Fetch(); err != nil {
+	if err = repo.Repository.Fetch(&git.FetchOptions{Tags: git.AllTags}); err != nil {
 		return nil, err
 	}
 
-	return repo, err
+	return &repo, err
 }
 
-func GenerateLibraryFromRepo(repo *git.Repository) (*metadata.LibraryMetadata, error) {
+func GenerateLibraryFromRepo(repo *Repository) (*metadata.LibraryMetadata, error) {
 	bytes, err := ioutil.ReadFile(filepath.Join(repo.FolderPath, "library.properties"))
 	if err != nil {
 		return nil, fmt.Errorf("can't read library.properties: %s", err)