diff --git a/cmd/cmd.go b/cmd/cmd.go
index 7a34f6ac83..94f3af1a8f 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -186,7 +186,7 @@ func tryInitSSHDockerClient() (dockerClient.CommonAPIClient, error) {
 			dockerClientOpts := []dockerClient.Opt{
 				dockerClient.WithVersion("1.38"),
 				dockerClient.WithHTTPClient(httpClient),
-				dockerClient.WithHost("http://example.com/"),
+				dockerClient.WithHost("http://dummy/"),
 				dockerClient.WithDialContext(dialContext),
 			}
 			return dockerClient.NewClientWithOpts(dockerClientOpts...)
@@ -235,7 +235,7 @@ func readSecret(prompt string) (pw []byte, err error) {
 	}
 }
 
-func newPasswordCbk() sshdialer.PasswordCallback {
+func newPasswordCbk() sshdialer.SecretCallback {
 	var pwdSet bool
 	var pwd string
 	return func() (string, error) {
@@ -254,7 +254,7 @@ func newPasswordCbk() sshdialer.PasswordCallback {
 	}
 }
 
-func newPassPhraseCbk() sshdialer.PassPhraseCallback {
+func newPassPhraseCbk() sshdialer.SecretCallback {
 	var pwdSet bool
 	var pwd string
 	return func() (string, error) {
diff --git a/internal/sshdialer/ssh_dialer.go b/internal/sshdialer/ssh_dialer.go
index a54765dcf0..a053ae5556 100644
--- a/internal/sshdialer/ssh_dialer.go
+++ b/internal/sshdialer/ssh_dialer.go
@@ -24,18 +24,19 @@ import (
 	"golang.org/x/crypto/ssh/knownhosts"
 )
 
-type PasswordCallback func() (string, error)
-type PassPhraseCallback func() (string, error)
+type SecretCallback func() (string, error)
 type HostKeyCallback func(hostPort string, pubKey ssh.PublicKey) error
 
 type Config struct {
 	Identity           string
 	PassPhrase         string
-	PasswordCallback   PasswordCallback
-	PassPhraseCallback PassPhraseCallback
+	PasswordCallback   SecretCallback
+	PassPhraseCallback SecretCallback
 	HostKeyCallback    HostKeyCallback
 }
 
+const defaultSSHPort = "22"
+
 func NewDialContext(url *urlPkg.URL, config Config) (func(ctx context.Context, network, addr string) (net.Conn, error), error) {
 	sshConfig, err := NewSSHClientConfig(url, config)
 	if err != nil {
@@ -44,7 +45,7 @@ func NewDialContext(url *urlPkg.URL, config Config) (func(ctx context.Context, n
 
 	port := url.Port()
 	if port == "" {
-		port = "22"
+		port = defaultSSHPort
 	}
 	host := url.Hostname()
 
@@ -319,7 +320,7 @@ func NewSSHClientConfig(url *urlPkg.URL, credentialsConfig Config) (*ssh.ClientC
 	return clientConfig, nil
 }
 
-func publicKey(path string, passphrase []byte, passPhraseCallback PassPhraseCallback) (ssh.Signer, error) {
+func publicKey(path string, passphrase []byte, passPhraseCallback SecretCallback) (ssh.Signer, error) {
 	key, err := ioutil.ReadFile(path)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read key file: %w", err)
@@ -348,7 +349,7 @@ func publicKey(path string, passphrase []byte, passPhraseCallback PassPhraseCall
 
 func createHostKeyCallback(hostKeyCallback HostKeyCallback) func(hostPort string, remote net.Addr, key ssh.PublicKey) error {
 	return func(hostPort string, remote net.Addr, pubKey ssh.PublicKey) error {
-		host, port := hostPort, "22"
+		host, port := hostPort, defaultSSHPort
 		if _h, _p, err := net.SplitHostPort(host); err == nil {
 			host, port = _h, _p
 		}
@@ -381,7 +382,7 @@ func createHostKeyCallback(hostKeyCallback HostKeyCallback) func(hostPort string
 			}
 
 			for _, hp := range hostPorts {
-				h, p := hp, "22"
+				h, p := hp, defaultSSHPort
 				if _h, _p, err := net.SplitHostPort(hp); err == nil {
 					h, p = _h, _p
 				}