feat(client): Add support for SSH tunneling (#1298)

* feat(client): Add support for SSH tunneling

* Fix test

config/tunneling/sshtunnel/sshtunnel_test.go

@@ -0,0 +1,158 @@
+package sshtunnel
+
+import (
+	"testing"
+)
+
+func TestConfig_ValidateAndSetDefaults(t *testing.T) {
+	tests := []struct {
+		name    string
+		config  *Config
+		wantErr bool
+		errMsg  string
+	}{
+		{
+			name: "valid SSH config with private key",
+			config: &Config{
+				Type:       "SSH",
+				Host:       "example.com",
+				Username:   "test",
+				PrivateKey: "-----BEGIN RSA PRIVATE KEY-----\ntest\n-----END RSA PRIVATE KEY-----",
+			},
+			wantErr: false,
+		},
+		{
+			name: "valid SSH config with password",
+			config: &Config{
+				Type:     "SSH",
+				Host:     "example.com",
+				Username: "test",
+				Password: "secret",
+			},
+			wantErr: false,
+		},
+		{
+			name: "valid SSH config with custom port",
+			config: &Config{
+				Type:     "SSH",
+				Host:     "example.com",
+				Port:     2222,
+				Username: "test",
+				Password: "secret",
+			},
+			wantErr: false,
+		},
+		{
+			name: "sets default port 22",
+			config: &Config{
+				Type:     "SSH",
+				Host:     "example.com",
+				Username: "test",
+				Password: "secret",
+			},
+			wantErr: false,
+		},
+		{
+			name: "invalid type",
+			config: &Config{
+				Type:     "INVALID",
+				Host:     "example.com",
+				Username: "test",
+				Password: "secret",
+			},
+			wantErr: true,
+			errMsg:  "unsupported tunnel type: INVALID",
+		},
+		{
+			name: "missing host",
+			config: &Config{
+				Type:     "SSH",
+				Username: "test",
+				Password: "secret",
+			},
+			wantErr: true,
+			errMsg:  "host is required",
+		},
+		{
+			name: "missing username",
+			config: &Config{
+				Type:     "SSH",
+				Host:     "example.com",
+				Password: "secret",
+			},
+			wantErr: true,
+			errMsg:  "username is required",
+		},
+		{
+			name: "missing authentication",
+			config: &Config{
+				Type:     "SSH",
+				Host:     "example.com",
+				Username: "test",
+			},
+			wantErr: true,
+			errMsg:  "either private-key or password is required",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			originalPort := tt.config.Port
+			err := tt.config.ValidateAndSetDefaults()
+			if tt.wantErr {
+				if err == nil {
+					t.Errorf("ValidateAndSetDefaults() expected error but got none")
+					return
+				}
+				if err.Error() != tt.errMsg {
+					t.Errorf("ValidateAndSetDefaults() error = %v, want %v", err.Error(), tt.errMsg)
+				}
+				return
+			}
+			if err != nil {
+				t.Errorf("ValidateAndSetDefaults() unexpected error = %v", err)
+				return
+			}
+			// Check that default port is set
+			if originalPort == 0 && tt.config.Port != 22 {
+				t.Errorf("ValidateAndSetDefaults() expected default port 22, got %d", tt.config.Port)
+			}
+		})
+	}
+}
+
+func TestNew(t *testing.T) {
+	config := &Config{
+		Type:     "SSH",
+		Host:     "example.com",
+		Username: "test",
+		Password: "secret",
+	}
+	tunnel := New(config)
+	if tunnel == nil {
+		t.Error("New() returned nil")
+		return
+	}
+	if tunnel.config != config {
+		t.Error("New() did not set config correctly")
+	}
+}
+
+func TestSSHTunnel_Close(t *testing.T) {
+	config := &Config{
+		Type:     "SSH",
+		Host:     "example.com",
+		Username: "test",
+		Password: "secret",
+	}
+	tunnel := New(config)
+	// Test closing when no client is set
+	err := tunnel.Close()
+	if err != nil {
+		t.Errorf("Close() with no client returned error: %v", err)
+	}
+	// Test closing multiple times
+	err = tunnel.Close()
+	if err != nil {
+		t.Errorf("Close() called twice returned error: %v", err)
+	}
+}