sync: Try to use a ssh key if no ssh-agent configured

admin/sync/importer_git.go

@@ -2,10 +2,14 @@ package sync
 
 import (
 	"bufio"
+	"io/ioutil"
+	"log"
 	"os"
+	"path"
 
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/config"
+	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
 )
 
 // GitImporter implements an Importer, where files to imports are located
@@ -13,12 +17,35 @@ import (
 type GitImporter struct {
 	li     LocalImporter
 	Remote string
+	Auth   ssh.AuthMethod
 }
 
 func NewGitImporter(li LocalImporter, remote string) GitImporter {
+	var auth ssh.AuthMethod
+
+	// If there is no ssh-agent setup, try to use a default ssh key
+	if _, exists := os.LookupEnv("SSH_AUTH_SOCK"); !exists {
+		if home, exists := os.LookupEnv("HOME"); exists {
+			for _, d := range []string{"id_fic", "id_ed25519", "id_rsa"} {
+				pemBytes, err := ioutil.ReadFile(path.Join(home, ".ssh", d))
+				if err == nil {
+					log.Println("[GitImporter] Using", path.Join(home, ".ssh", d), "as ssh key to sync repository")
+					auth, err = ssh.NewPublicKeys("git", pemBytes, "")
+					if ccfg, err := auth.ClientConfig(); err != nil {
+						if hkc, err := ssh.NewKnownHostsCallback(); err != nil {
+							ccfg.HostKeyCallback = hkc
+						}
+					}
+					break
+				}
+			}
+		}
+	}
+
 	return GitImporter{
 		li:     li,
 		Remote: remote,
+		Auth:   auth,
 	}
 }
 
@@ -57,6 +84,7 @@ func (i GitImporter) Init() error {
 		_, err = git.PlainClone(i.li.Base, false, &git.CloneOptions{
 			URL:               i.Remote,
 			RecurseSubmodules: git.DefaultSubmoduleRecursionDepth,
+			Auth:              i.Auth,
 		})
 		if err != nil {
 			return err
@@ -98,6 +126,7 @@ func (i GitImporter) Sync() error {
 		Depth:             1,
 		RecurseSubmodules: git.DefaultSubmoduleRecursionDepth,
 		Force:             true,
+		Auth:              i.Auth,
 	})
 	return err
 }