chore: allows to specify IP protocol (#261)

* Allows to specify IP protocol, including IPv4 only

* Add tests forcing IPv4 or IPv6

DOCS.md

@@ -178,6 +178,23 @@ Example configuration for passphrase which protecting a private key:
         - echo "you can't see the steps."
 ```
 
+Example configuration for forcing protocol to IPv4 only:
+
+```diff
+  - name: ssh commands
+    image: ghcr.io/appleboy/drone-ssh
+    settings:
+      host: foo.com
+      username: root
+      password: 1234
+      port: 22
++     protocol: tcp4
+      script:
+        - echo hello
+        - echo world
+```
+
+
 ## Secret Reference
 
 | Key | Description |
@@ -197,6 +214,7 @@ Example configuration for passphrase which protecting a private key:
 |-----|-------------|
 | `host` | target hostname or IP |
 | `port` | ssh port of target host |
+| `protocol` | IP protocol to use: either tcp, tcp4 or tcp6 |
 | `username` | account for target host user |
 | `password` | password for target host user |
 | `key` | plain text of user private key |
@@ -208,6 +226,7 @@ Example configuration for passphrase which protecting a private key:
 | `command_timeout` | Command timeout is the maximum amount of time for the execute commands, default is 10 minutes. |
 | `proxy_host` | proxy hostname or IP |
 | `proxy_port` | ssh port of proxy host |
+| `proxy_protocol` | IP protocol to use for the proxy: either tcp, tcp4 or tcp6 |
 | `proxy_username` | account for proxy host user |
 | `proxy_password` | password for proxy host user |
 | `proxy_key` | plain text of proxy private key |

go.mod

@@ -3,7 +3,7 @@ module github.com/appleboy/drone-ssh
 go 1.18
 
 require (
-	github.com/appleboy/easyssh-proxy v1.3.10
+	github.com/appleboy/easyssh-proxy v1.3.11-0.20230609114136-a50c12e64039
 	github.com/joho/godotenv v1.5.1
 	github.com/stretchr/testify v1.8.4
 	github.com/urfave/cli/v2 v2.25.7

go.sum

@@ -1,7 +1,7 @@
 github.com/ScaleFT/sshkeys v1.2.0 h1:5BRp6rTVIhJzXT3VcUQrKgXR8zWA3sOsNeuyW15WUA8=
 github.com/ScaleFT/sshkeys v1.2.0/go.mod h1:gxOHeajFfvGQh/fxlC8oOKBe23xnnJTif00IFFbiT+o=
-github.com/appleboy/easyssh-proxy v1.3.10 h1:iriF68tlrYoxgWhS7t7Wyr0FA+hJlOem5tMfm+RDlx4=
-github.com/appleboy/easyssh-proxy v1.3.10/go.mod h1:T81pu/Cxx/zf/7YXhFCFiucBa4xeQ81ci5b0PFnMRJc=
+github.com/appleboy/easyssh-proxy v1.3.11-0.20230609114136-a50c12e64039 h1:u1o1Ft7PltG4+iOAmEubuyXx5fiDHWIvP+JiCClL+ak=
+github.com/appleboy/easyssh-proxy v1.3.11-0.20230609114136-a50c12e64039/go.mod h1:6nn1KPv9GP9BrK8tgl+d/w68jX4rpLeooO3FAcC/lds=
 github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHHBfMQ6w=
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

main.go

@@ -51,6 +51,12 @@ func main() {
 			EnvVars: []string{"PLUGIN_PORT", "SSH_PORT", "INPUT_PORT"},
 			Value:   22,
 		},
+		&cli.StringFlag{
+			Name:    "protocol",
+			Usage:   "The IP protocol to use. Default to tcp (both IPv4 and IPv6).",
+			EnvVars: []string{"PLUGIN_PROTOCOL", "SSH_PROTOCOL", "INPUT_PROTOCOL"},
+			Value:   "tcp",
+		},
 		&cli.StringFlag{
 			Name:    "username",
 			Aliases: []string{"user", "u"},
@@ -141,6 +147,12 @@ func main() {
 			EnvVars: []string{"PLUGIN_PROXY_PORT", "PROXY_SSH_PORT", "INPUT_PROXY_PORT"},
 			Value:   "22",
 		},
+		&cli.StringFlag{
+			Name:    "proxy.protocol",
+			Usage:   "The IP protocol to use for the proxy. Default to tcp (both IPv4 and IPv6).",
+			EnvVars: []string{"PLUGIN_PROTOCOL", "SSH_PROTOCOL", "INPUT_PROTOCOL"},
+			Value:   "tcp",
+		},
 		&cli.StringFlag{
 			Name:    "proxy.username",
 			Usage:   "connect as user of proxy",
@@ -259,6 +271,7 @@ func run(c *cli.Context) error {
 			Fingerprint:       c.String("fingerprint"),
 			Host:              c.StringSlice("host"),
 			Port:              c.Int("port"),
+			Protocol:          easyssh.Protocol(c.String("protocol")),
 			Timeout:           c.Duration("timeout"),
 			CommandTimeout:    c.Duration("command.timeout"),
 			Script:            scripts,
@@ -278,6 +291,7 @@ func run(c *cli.Context) error {
 				Fingerprint:       c.String("proxy.fingerprint"),
 				Server:            c.String("proxy.host"),
 				Port:              c.String("proxy.port"),
+				Protocol:          easyssh.Protocol(c.String("proxy.protocol")),
 				Timeout:           c.Duration("proxy.timeout"),
 				Ciphers:           c.StringSlice("proxy.ciphers"),
 				UseInsecureCipher: c.Bool("proxy.useInsecureCipher"),

plugin.go

@@ -30,6 +30,7 @@ type (
 		Password          string
 		Host              []string
 		Port              int
+		Protocol          easyssh.Protocol
 		Fingerprint       string
 		Timeout           time.Duration
 		CommandTimeout    time.Duration
@@ -75,6 +76,7 @@ func (p Plugin) exec(host string, wg *sync.WaitGroup, errChannel chan error) {
 		User:              p.Config.Username,
 		Password:          p.Config.Password,
 		Port:              port,
+		Protocol:          p.Config.Protocol,
 		Key:               p.Config.Key,
 		KeyPath:           p.Config.KeyPath,
 		Passphrase:        p.Config.Passphrase,
@@ -87,6 +89,7 @@ func (p Plugin) exec(host string, wg *sync.WaitGroup, errChannel chan error) {
 			User:              p.Config.Proxy.User,
 			Password:          p.Config.Proxy.Password,
 			Port:              p.Config.Proxy.Port,
+			Protocol:          p.Config.Proxy.Protocol,
 			Key:               p.Config.Proxy.Key,
 			KeyPath:           p.Config.Proxy.KeyPath,
 			Passphrase:        p.Config.Proxy.Passphrase,

plugin_test.go

@@ -113,6 +113,40 @@ func TestSSHScriptFromKeyFile(t *testing.T) {
 	assert.Nil(t, err)
 }
 
+func TestSSHIPv4Only(t *testing.T) {
+	plugin := Plugin{
+		Config: Config{
+			Host:           []string{"localhost", "127.0.0.1"},
+			Username:       "drone-scp",
+			Port:           22,
+			Protocol:       easyssh.PROTOCOL_TCP4,
+			KeyPath:        "./tests/.ssh/id_rsa",
+			Script:         []string{"whoami", "ls -al"},
+			CommandTimeout: 60 * time.Second,
+		},
+	}
+
+	err := plugin.Exec()
+	assert.Nil(t, err)
+}
+
+func TestSSHIPv6OnlyError(t *testing.T) {
+	plugin := Plugin{
+		Config: Config{
+			Host:           []string{"127.0.0.1"},
+			Username:       "drone-scp",
+			Port:           22,
+			Protocol:       easyssh.PROTOCOL_TCP6,
+			KeyPath:        "./tests/.ssh/id_rsa",
+			Script:         []string{"whoami", "ls -al"},
+			CommandTimeout: 60 * time.Second,
+		},
+	}
+
+	err := plugin.Exec()
+	assert.NotNil(t, err)
+}
+
 func TestStreamFromSSHCommand(t *testing.T) {
 	plugin := Plugin{
 		Config: Config{