backend/plugins/gitextractor/parser/clone.go

/*
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements.  See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package parser

import (
	"encoding/base64"
	"fmt"
	"github.com/apache/incubator-devlake/core/errors"
	"net"
	"os"

	gogit "github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
	git "github.com/libgit2/git2go/v33"
	ssh2 "golang.org/x/crypto/ssh"
)

// We have done comparison experiments for git2go and go-git, and the results show that git2go has better performance.
// We kept go-git because it supports cloning via key-based SSH.

const DefaultUser = "git"

func cloneOverSSH(url, dir, passphrase string, pk []byte) errors.Error {
	key, err := ssh.NewPublicKeys(DefaultUser, pk, passphrase)
	if err != nil {
		return errors.Convert(err)
	}
	key.HostKeyCallbackHelper = ssh.HostKeyCallbackHelper{
		HostKeyCallback: func(hostname string, remote net.Addr, key ssh2.PublicKey) error {
			return nil
		},
	}
	_, err = gogit.PlainClone(dir, true, &gogit.CloneOptions{
		URL:  url,
		Auth: key,
	})
	if err != nil {
		return errors.Convert(err)
	}
	return nil
}

func (l *GitRepoCreator) CloneOverHTTP(repoId, url, user, password, proxy string) (*GitRepo, errors.Error) {
	return withTempDirectory(func(dir string) (*GitRepo, error) {
		cloneOptions := &git.CloneOptions{Bare: true}
		if proxy != "" {
			cloneOptions.FetchOptions.ProxyOptions.Type = git.ProxyTypeAuto
			cloneOptions.FetchOptions.ProxyOptions.Url = proxy
		}
		if user != "" {
			auth := fmt.Sprintf("Authorization: Basic %s", base64.StdEncoding.EncodeToString([]byte(user+":"+password)))
			cloneOptions.FetchOptions.Headers = []string{auth}
		}
		clonedRepo, err := git.Clone(url, dir, cloneOptions)
		if err != nil {
			return nil, err
		}
		return l.newGitRepo(repoId, clonedRepo), nil
	})
}

func (l *GitRepoCreator) CloneOverSSH(repoId, url, privateKey, passphrase string) (*GitRepo, errors.Error) {
	return withTempDirectory(func(dir string) (*GitRepo, error) {
		pk, err := base64.StdEncoding.DecodeString(privateKey)
		if err != nil {
			return nil, err
		}
		err = cloneOverSSH(url, dir, passphrase, pk)
		if err != nil {
			return nil, err
		}
		return l.LocalRepo(dir, repoId)
	})
}

func withTempDirectory(f func(tempDir string) (*GitRepo, error)) (*GitRepo, errors.Error) {
	dir, err := os.MkdirTemp("", "gitextractor")
	if err != nil {
		return nil, errors.Convert(err)
	}
	cleanup := func() {
		_ = os.RemoveAll(dir)
	}
	defer func() {
		if err != nil {
			cleanup()
		}
	}()
	repo, err := f(dir)
	if err != nil {
		return nil, errors.Convert(err)
	}
	repo.cleanup = cleanup
	return repo, errors.Convert(err)
}