feat: add sftp implementation

plugins/common/sftp.go

@@ -0,0 +1,262 @@
+package common
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"strconv"
+	"syscall"
+
+	"github.com/melbahja/goph"
+	"golang.org/x/crypto/ssh"
+)
+
+// SftpCopyInput is the input for CallSftpCopy
+type SftpCopyInput struct {
+	// SourcePath is the path to the file to copy
+	SourcePath string
+
+	// DestinationPath is the path to copy the file to
+	DestinationPath string
+
+	// AllowUknownHosts allows connecting to hosts with unknown host keys
+	AllowUknownHosts bool
+
+	// RemoteHost is the remote host to connect to
+	RemoteHost string
+
+	// Sudo runs the command with sudo -n -u root
+	Sudo bool
+}
+
+// CallSftpCopy copies a file to a remote host via sftp
+func CallSftpCopy(input SftpCopyInput) (SftpCopyResult, error) {
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, os.Interrupt, syscall.SIGHUP,
+		syscall.SIGINT,
+		syscall.SIGQUIT,
+		syscall.SIGTERM)
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		<-signals
+		cancel()
+	}()
+
+	u, err := url.Parse(input.RemoteHost)
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to parse remote host: %w", err)
+	}
+	if u.Scheme == "" {
+		return SftpCopyResult{}, fmt.Errorf("missing remote host ssh scheme in remote host: %s", input.RemoteHost)
+	}
+	if u.Scheme != "ssh" {
+		return SftpCopyResult{}, fmt.Errorf("invalid remote host scheme: %s", u.Scheme)
+	}
+
+	username := ""
+	password := ""
+	if u.User != nil {
+		username = u.User.Username()
+		if pass, ok := u.User.Password(); ok {
+			password = pass
+		}
+	}
+	if username == "" {
+		username = os.Getenv("USER")
+	}
+
+	portStr := u.Port()
+	port := 0
+	if portStr != "" {
+		portVal, err := strconv.Atoi(portStr)
+		if err != nil {
+			return SftpCopyResult{}, fmt.Errorf("failed to parse port: %w", err)
+		}
+		port = portVal
+	}
+	if port == 0 {
+		port = 22
+	}
+
+	sshKeyPath := filepath.Join(os.Getenv("DOKKU_ROOT"), ".ssh/id_ed25519")
+	if !FileExists(sshKeyPath) {
+		sshKeyPath = filepath.Join(os.Getenv("DOKKU_ROOT"), ".ssh/id_rsa")
+	}
+	if !FileExists(sshKeyPath) {
+		return SftpCopyResult{}, errors.New("ssh key not found at ~/.ssh/id_ed25519 or ~/.ssh/id_rsa")
+	}
+
+	cmd := SftpCopyTask{
+		SourcePath:       input.SourcePath,
+		DestinationPath:  input.DestinationPath,
+		AllowUknownHosts: input.AllowUknownHosts,
+		Hostname:         u.Hostname(),
+		Port:             uint(port),
+		Username:         username,
+		Password:         password,
+		SshKeyPath:       sshKeyPath,
+	}
+
+	if os.Getenv("DOKKU_TRACE") == "1" {
+		cmd.PrintCommand = true
+	}
+
+	res, err := cmd.Execute(ctx)
+	if err != nil {
+		return res, err
+	}
+
+	return res, nil
+}
+
+type SftpCopyTask struct {
+	// SourcePath is the path to the file to copy
+	SourcePath string
+
+	// DestinationPath is the path to copy the file to
+	DestinationPath string
+
+	// Shell run the command in a bash shell.
+	// Note that the system must have `bash` installed in the PATH or in /bin/bash
+	Shell bool
+
+	// Stdin connect a reader to stdin for the command
+	// being executed.
+	Stdin io.Reader
+
+	// PrintCommand prints the command before executing
+	PrintCommand bool
+
+	// AllowUknownHosts allows connecting to hosts with unknown host keys
+	AllowUknownHosts bool
+
+	// Hostname is the hostname to connect to
+	Hostname string
+
+	// Port is the port to connect to
+	Port uint
+
+	// Username is the username to connect with
+	Username string
+
+	// Password is the password to connect with
+	Password string
+
+	// SshKeyPath is the path to the ssh key to use
+	SshKeyPath string
+}
+
+// SftpCopyResult is the result of executing an SftpCopyTask
+type SftpCopyResult struct {
+	ExitErr   error
+	Cancelled bool
+}
+
+// Execute runs the task
+func (task SftpCopyTask) Execute(ctx context.Context) (SftpCopyResult, error) {
+	if task.SourcePath == "" {
+		return SftpCopyResult{}, errors.New("source path is required")
+	}
+	if task.DestinationPath == "" {
+		return SftpCopyResult{}, errors.New("destination path is required")
+	}
+	if task.Hostname == "" {
+		return SftpCopyResult{}, errors.New("hostname is required")
+	}
+	if task.SshKeyPath == "" {
+		return SftpCopyResult{}, errors.New("ssh key path is required")
+	}
+	if task.Username == "" {
+		return SftpCopyResult{}, errors.New("username is required")
+	}
+	if task.Port == 0 {
+		task.Port = 22
+	}
+
+	auth, err := goph.Key(task.SshKeyPath, "")
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to load ssh key: %w", err)
+	}
+
+	callback, err := goph.DefaultKnownHosts()
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to load known hosts: %w", err)
+	}
+
+	if task.AllowUknownHosts {
+		callback = ssh.InsecureIgnoreHostKey()
+	}
+
+	connectionConf := goph.Config{
+		User:     task.Username,
+		Addr:     task.Hostname,
+		Port:     task.Port,
+		Timeout:  goph.DefaultTimeout,
+		Callback: callback,
+		Auth:     auth,
+	}
+	if task.Password != "" {
+		connectionConf.Auth = goph.Password(task.Password)
+	}
+
+	client, err := goph.NewConn(&connectionConf)
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to create ssh client: %w", err)
+	}
+	defer client.Close()
+
+	// don't try to run if the context is already cancelled
+	if ctx.Err() != nil {
+		return SftpCopyResult{
+			Cancelled: ctx.Err() == context.Canceled,
+		}, ctx.Err()
+	}
+
+	if task.PrintCommand {
+		LogDebug(fmt.Sprintf("ssh %s@%s cp %s %v", task.Username, task.Hostname, task.SourcePath, task.DestinationPath))
+	}
+
+	sftp, err := client.NewSftp()
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to create sftp client: %w", err)
+	}
+
+	srcFile, err := os.Open(task.SourcePath)
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to open source file: %w", err)
+	}
+	defer srcFile.Close()
+
+	var contents []byte
+	_, err = srcFile.Read(contents)
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to read source file: %w", err)
+	}
+
+	dstFile, err := sftp.Create(task.DestinationPath)
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to create destination file: %w", err)
+	}
+
+	_, err = dstFile.Write(contents)
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to write to destination file: %w", err)
+	}
+
+	err = dstFile.Close()
+	if err != nil {
+		return SftpCopyResult{}, fmt.Errorf("failed to create ssh command: %w", err)
+	}
+
+	err = sftp.Close()
+
+	return SftpCopyResult{
+		ExitErr:   err,
+		Cancelled: ctx.Err() == context.Canceled,
+	}, ctx.Err()
+}