feat: Support import private key from file path.

main.go

@@ -30,6 +30,11 @@ func main() {
 			Usage:  "private ssh key",
 			EnvVar: "PLUGIN_SSH_KEY,PLUGIN_KEY,SSH_KEY",
 		},
+		cli.StringFlag{
+			Name:   "key-path",
+			Usage:  "ssh private key path",
+			EnvVar: "PLUGIN_KEY_PATH,SSH_KEY_PATH",
+		},
 		cli.StringFlag{
 			Name:   "user",
 			Usage:  "connect as user",
@@ -117,6 +122,7 @@ func run(c *cli.Context) error {
 	plugin := Plugin{
 		Config: Config{
 			Key:      c.String("ssh-key"),
+			KeyPath:  c.String("key-path"),
 			User:     c.String("user"),
 			Password: c.String("password"),
 			Host:     c.StringSlice("host"),

plugin.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"log"
 	"net"
 	"os"
@@ -17,12 +18,14 @@ const (
 	missingPasswordOrKey = "Error: can't connect without a private SSH key or password"
 	unableConnectServer  = "Error: Failed to start a SSH session"
 	failParsePrivateKey  = "Error: Failed to parse private key"
+	sshKeyNotFound       = "ssh: no key found"
 )
 
 type (
 	// Config for the plugin.
 	Config struct {
 		Key      string
+		KeyPath  string
 		User     string
 		Password string
 		Host     []string
@@ -38,13 +41,29 @@ type (
 	}
 )
 
+// returns ssh.Signer from user you running app home path + cutted key path.
+// (ex. pubkey,err := getKeyFile("/.ssh/id_rsa") )
+func getKeyFile(keypath string) (ssh.Signer, error) {
+	buf, err := ioutil.ReadFile(keypath)
+	if err != nil {
+		return nil, err
+	}
+
+	pubkey, err := ssh.ParsePrivateKey(buf)
+	if err != nil {
+		return nil, err
+	}
+
+	return pubkey, nil
+}
+
 // Exec executes the plugin.
 func (p Plugin) Exec() error {
 	if len(p.Config.Host) == 0 && p.Config.User == "" {
 		return fmt.Errorf(missingHostOrUser)
 	}
 
-	if p.Config.Key == "" && p.Config.Password == "" {
+	if p.Config.Key == "" && p.Config.Password == "" && p.Config.KeyPath == "" {
 		return fmt.Errorf(missingPasswordOrKey)
 	}
 
@@ -57,6 +76,16 @@ func (p Plugin) Exec() error {
 		// auths holds the detected ssh auth methods
 		auths := []ssh.AuthMethod{}
 
+		if p.Config.KeyPath != "" {
+			pubkey, err := getKeyFile(p.Config.KeyPath)
+
+			if err != nil {
+				return err
+			}
+
+			auths = append(auths, ssh.PublicKeys(pubkey))
+		}
+
 		if p.Config.Key != "" {
 			signer, err := ssh.ParsePrivateKey([]byte(p.Config.Key))
 

plugin_test.go

@@ -61,7 +61,7 @@ func TestFailParsePrivateKey(t *testing.T) {
 	assert.Equal(t, failParsePrivateKey, err.Error())
 }
 
-func TestSSHScript(t *testing.T) {
+func TestSSHScriptFromRawKey(t *testing.T) {
 	plugin := Plugin{
 		Config: Config{
 			Host: []string{"localhost"},
@@ -102,3 +102,50 @@ ib4KbP5ovZlrjL++akMQ7V2fHzuQIFWnCkDA5c2ZAqzlM+ZN+HRG7gWur7Bt4XH1
 	err := plugin.Exec()
 	assert.Nil(t, err)
 }
+
+func TestWrongKeyPath(t *testing.T) {
+	plugin := Plugin{
+		Config: Config{
+			Host:    []string{"localhost"},
+			User:    "drone-scp",
+			Port:    22,
+			KeyPath: "/appleboy",
+			Script:  []string{"whoami"},
+		},
+	}
+
+	err := plugin.Exec()
+	assert.NotNil(t, err)
+	assert.Equal(t, "open /appleboy: no such file or directory", err.Error())
+}
+
+func TestWrongKeyFormat(t *testing.T) {
+	plugin := Plugin{
+		Config: Config{
+			Host:    []string{"localhost"},
+			User:    "drone-scp",
+			Port:    22,
+			KeyPath: "./tests/.ssh/id_rsa.pub",
+			Script:  []string{"whoami"},
+		},
+	}
+
+	err := plugin.Exec()
+	assert.NotNil(t, err)
+	assert.Equal(t, sshKeyNotFound, err.Error())
+}
+
+func TestSSHScriptFromKeyFile(t *testing.T) {
+	plugin := Plugin{
+		Config: Config{
+			Host:    []string{"localhost"},
+			User:    "drone-scp",
+			Port:    22,
+			KeyPath: "./tests/.ssh/id_rsa",
+			Script:  []string{"whoami"},
+		},
+	}
+
+	err := plugin.Exec()
+	assert.Nil(t, err)
+}