core/installer/soft/client.go

package soft

import (
	"errors"
	"fmt"
	"golang.org/x/crypto/ssh"
	"log"
	"net"
	"os"
	"regexp"
	"slices"
	"strings"
	"time"

	"github.com/cenkalti/backoff/v4"
	"github.com/go-git/go-billy/v5/memfs"
	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing/transport"
	gitssh "github.com/go-git/go-git/v5/plumbing/transport/ssh"
	"github.com/go-git/go-git/v5/storage/memory"
)

var ErrorAlreadyExists = errors.New("already exists")

type Client interface {
	Address() string
	Signer() ssh.Signer
	GetPublicKeys() ([]string, error)
	RepoExists(name string) (bool, error)
	GetRepo(name string) (RepoIO, error)
	GetRepoAddress(name string) string
	AddRepository(name string) error
	UserExists(name string) (bool, error)
	FindUser(pubKey string) (string, error)
	AddUser(name, pubKey string) error
	AddPublicKey(user string, pubKey string) error
	RemovePublicKey(user string, pubKey string) error
	MakeUserAdmin(name string) error
	AddReadWriteCollaborator(repo, user string) error
	AddReadOnlyCollaborator(repo, user string) error
	AddWebhook(repo, url string, opts ...string) error
}

type realClient struct {
	addr     string
	signer   ssh.Signer
	log      *log.Logger
	pemBytes []byte
}

func NewClient(addr string, clientPrivateKey []byte, log *log.Logger) (Client, error) {
	signer, err := ssh.ParsePrivateKey(clientPrivateKey)
	if err != nil {
		return nil, err
	}
	log.SetPrefix("SOFT-SERVE: ")
	log.Printf("Created signer")
	return &realClient{
		addr,
		signer,
		log,
		clientPrivateKey,
	}, nil
}

type ClientGetter interface {
	Get(addr string, clientPrivateKey []byte, log *log.Logger) (Client, error)
}

type RealClientGetter struct{}

func (c RealClientGetter) Get(addr string, clientPrivateKey []byte, log *log.Logger) (Client, error) {
	var client Client
	err := backoff.RetryNotify(func() error {
		var err error
		client, err = NewClient(addr, clientPrivateKey, log)
		if err != nil {
			return err
		}
		if _, err := client.GetPublicKeys(); err != nil {
			return err
		}
		return nil
	}, backoff.NewConstantBackOff(5*time.Second), func(err error, _ time.Duration) {
		log.Printf("Failed to create client:  %s\n", err.Error())
	})
	return client, err
}

func (ss *realClient) Address() string {
	return ss.addr
}

func (ss *realClient) Signer() ssh.Signer {
	return ss.signer
}

func (ss *realClient) UserExists(name string) (bool, error) {
	log.Printf("Checking user exists %s", name)
	out, err := ss.RunCommand("user", "list")
	if err != nil {
		return false, err
	}
	return slices.Contains(strings.Fields(out), name), nil
}

func (ss *realClient) FindUser(pubKey string) (string, error) {
	log.Printf("Finding user %s", pubKey)
	pk := strings.Join(strings.Fields(pubKey)[:2], " ")
	out, err := ss.RunCommand("user", "list")
	if err != nil {
		return "", err
	}
	for _, user := range strings.Fields(out) {
		info, err := ss.RunCommand("user", "info", user)
		if err != nil {
			return "", err
		}
		if strings.Contains(info, pk) {
			return user, nil
		}
	}
	return "", nil
}

func (ss *realClient) AddUser(name, pubKey string) error {
	log.Printf("Adding user %s", name)
	if _, err := ss.RunCommand("user", "create", name); err != nil {
		return err
	}
	return ss.AddPublicKey(name, pubKey)
}

func (ss *realClient) MakeUserAdmin(name string) error {
	log.Printf("Making user %s admin", name)
	_, err := ss.RunCommand("user", "set-admin", name, "true")
	return err
}

func (ss *realClient) AddPublicKey(user string, pubKey string) error {
	log.Printf("Adding public key: %s %s\n", user, pubKey)
	_, err := ss.RunCommand("user", "add-pubkey", user, pubKey)
	return err
}

func (ss *realClient) RemovePublicKey(user string, pubKey string) error {
	log.Printf("Removing public key: %s %s\n", user, pubKey)
	_, err := ss.RunCommand("user", "remove-pubkey", user, pubKey)
	return err
}

func (ss *realClient) RunCommand(args ...string) (string, error) {
	cmd := strings.Join(args, " ")
	log.Printf("Running command %s", cmd)
	client, err := ssh.Dial("tcp", ss.addr, ss.sshClientConfig())
	if err != nil {
		return "", err
	}
	defer client.Close()
	session, err := client.NewSession()
	if err != nil {
		return "", err
	}
	defer session.Close()
	var buf strings.Builder
	session.Stdout = &buf
	session.Stderr = os.Stderr
	err = session.Run(cmd)
	return buf.String(), err
}

func (ss *realClient) RepoExists(name string) (bool, error) {
	out, err := ss.RunCommand("repo", "list")
	if err != nil {
		return false, err
	}
	return slices.Contains(strings.Fields(out), name), nil
}

func (ss *realClient) AddRepository(name string) error {
	log.Printf("Adding repository %s", name)
	if ok, err := ss.RepoExists(name); ok {
		return ErrorAlreadyExists
	} else if err != nil {
		return err
	}
	_, err := ss.RunCommand("repo", "create", name)
	return err
}

func (ss *realClient) AddReadWriteCollaborator(repo, user string) error {
	log.Printf("Adding read-write collaborator %s %s", repo, user)
	_, err := ss.RunCommand("repo", "collab", "add", repo, user, "read-write")
	return err
}

func (ss *realClient) AddReadOnlyCollaborator(repo, user string) error {
	log.Printf("Adding read-only collaborator %s %s", repo, user)
	_, err := ss.RunCommand("repo", "collab", "add", repo, user, "read-only")
	return err
}

func (ss *realClient) AddWebhook(repo, url string, opts ...string) error {
	log.Printf("Adding webhook %s %s", repo, url)
	_, err := ss.RunCommand(append(
		[]string{"repo", "webhook", "create", repo, url},
		opts...,
	)...)
	return err
}

type Repository struct {
	*git.Repository
	Addr RepositoryAddress
}

func (ss *realClient) GetRepo(name string) (RepoIO, error) {
	r, err := CloneRepository(RepositoryAddress{ss.addr, name}, ss.signer)
	if err != nil {
		return nil, err
	}
	return NewRepoIO(r, ss.signer)
}

type RepositoryAddress struct {
	Addr string
	Name string
}

func ParseRepositoryAddress(addr string) (RepositoryAddress, error) {
	items := regexp.MustCompile(`ssh://(.*)/(.*)`).FindStringSubmatch(addr)
	if len(items) != 3 {
		return RepositoryAddress{}, fmt.Errorf("Invalid address")
	}
	return RepositoryAddress{items[1], items[2]}, nil
}

func (r RepositoryAddress) FullAddress() string {
	return fmt.Sprintf("ssh://%s/%s", r.Addr, r.Name)
}

func CloneRepository(addr RepositoryAddress, signer ssh.Signer) (*Repository, error) {
	fmt.Printf("Cloning repository: %s %s\n", addr.Addr, addr.Name)
	c, err := git.Clone(memory.NewStorage(), memfs.New(), &git.CloneOptions{
		URL: addr.FullAddress(),
		Auth: &gitssh.PublicKeys{
			User:   "git",
			Signer: signer,
			HostKeyCallbackHelper: gitssh.HostKeyCallbackHelper{
				HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
					// TODO(giolekva): verify server public key
					fmt.Printf("--- %+v\n", ssh.MarshalAuthorizedKey(key))
					return nil
				},
			},
		},
		RemoteName:      "origin",
		ReferenceName:   "refs/heads/master",
		SingleBranch:    true,
		Depth:           1,
		InsecureSkipTLS: true,
		Progress:        os.Stdout,
	})
	if err != nil && !errors.Is(err, transport.ErrEmptyRemoteRepository) {
		return nil, err
	}
	wt, err := c.Worktree()
	if err != nil {
		return nil, err
	}
	sb, err := wt.Submodules()
	if err != nil {
		return nil, err
	}
	if err := sb.Init(); err != nil {
		return nil, err
	}
	if err := sb.Update(&git.SubmoduleUpdateOptions{
		Depth: 1,
	}); err != nil {
		return nil, err
	}
	return &Repository{
		Repository: c,
		Addr:       addr,
	}, nil
}

// TODO(giolekva): dead code
func (ss *realClient) authSSH() gitssh.AuthMethod {
	a, err := gitssh.NewPublicKeys("git", ss.pemBytes, "")
	if err != nil {
		panic(err)
	}
	a.HostKeyCallback = func(hostname string, remote net.Addr, key ssh.PublicKey) error {
		// TODO(giolekva): verify server public key
		ss.log.Printf("--- %+v\n", ssh.MarshalAuthorizedKey(key))
		return nil
	}
	return a
	// return &gitssh.PublicKeys{
	// 	User:   "git",
	// 	Signer: ss.Signer,
	// 	HostKeyCallbackHelper: gitssh.HostKeyCallbackHelper{
	// 		HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
	// 			// TODO(giolekva): verify server public key
	// 			ss.log.Printf("--- %+v\n", ssh.MarshalAuthorizedKey(key))
	// 			return nil
	// 		},
	// 	},
	// }
}

func (ss *realClient) authGit() *gitssh.PublicKeys {
	return &gitssh.PublicKeys{
		User:   "git",
		Signer: ss.signer,
		HostKeyCallbackHelper: gitssh.HostKeyCallbackHelper{
			HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
				// TODO(giolekva): verify server public key
				ss.log.Printf("--- %+v\n", ssh.MarshalAuthorizedKey(key))
				return nil
			},
		},
	}
}

func (ss *realClient) GetPublicKeys() ([]string, error) {
	var ret []string
	config := &ssh.ClientConfig{
		Auth: []ssh.AuthMethod{
			ssh.PublicKeys(ss.signer),
		},
		HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
			ret = append(ret, string(ssh.MarshalAuthorizedKey(key)))
			return nil
		},
	}
	client, err := ssh.Dial("tcp", ss.addr, config)
	if err != nil {
		return nil, err
	}
	defer client.Close()
	return ret, nil
}

func (ss *realClient) sshClientConfig() *ssh.ClientConfig {
	return &ssh.ClientConfig{
		Auth: []ssh.AuthMethod{
			ssh.PublicKeys(ss.signer),
		},
		HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
			// TODO(giolekva): verify server public key
			// fmt.Printf("## %s || %s -- \n", serverPubKey, ssh.MarshalAuthorizedKey(key))
			fmt.Printf("%s %s %s", hostname, remote, ssh.MarshalAuthorizedKey(key))
			return nil
		},
	}
}

func (ss *realClient) GetRepoAddress(name string) string {
	return fmt.Sprintf("%s/%s", ss.addressGit(), name)
}

func (ss *realClient) addressGit() string {
	return fmt.Sprintf("ssh://%s", ss.addr)
}