refactor(nginx): share the systemd defaults through settings getters

The /bin/systemctl and nginx.service fallbacks were copied into every
host command builder. Expose them as GetHostSystemctlPath and
GetHostSystemdUnitName next to the launchd getters so a default change
lands in one place.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/nginx/nginx.go

@@ -359,15 +359,7 @@ func hostReloadCommand(n *settings.Nginx) (string, []string) {
 	if n.GetHostServiceManager() == settings.HostServiceManagerLaunchd {
 		return n.GetHostSbinPath(), []string{"-s", "reload"}
 	}
-	systemctl := n.HostSystemctlPath
-	if systemctl == "" {
-		systemctl = "/bin/systemctl"
-	}
-	unit := n.HostSystemdUnitName
-	if unit == "" {
-		unit = "nginx.service"
-	}
-	return systemctl, []string{"reload", unit}
+	return n.GetHostSystemctlPath(), []string{"reload", n.GetHostSystemdUnitName()}
 }
 
 func hostRestartCommand(runner Runner, n *settings.Nginx) (string, []string, error) {
@@ -378,15 +370,7 @@ func hostRestartCommand(runner Runner, n *settings.Nginx) (string, []string, err
 		}
 		return n.GetHostLaunchctlPath(), []string{"kickstart", "-k", target}, nil
 	}
-	systemctl := n.HostSystemctlPath
-	if systemctl == "" {
-		systemctl = "/bin/systemctl"
-	}
-	unit := n.HostSystemdUnitName
-	if unit == "" {
-		unit = "nginx.service"
-	}
-	return systemctl, []string{"restart", unit}, nil
+	return n.GetHostSystemctlPath(), []string{"restart", n.GetHostSystemdUnitName()}, nil
 }
 
 func launchdTarget(runner Runner, service string) (string, error) {
@@ -428,15 +412,7 @@ func isRunningViaHostService() bool {
 }
 
 func hostSystemdStatusCommand(n *settings.Nginx) (string, []string) {
-	systemctl := n.HostSystemctlPath
-	if systemctl == "" {
-		systemctl = "/bin/systemctl"
-	}
-	unit := n.HostSystemdUnitName
-	if unit == "" {
-		unit = "nginx.service"
-	}
-	return systemctl, []string{"is-active", unit}
+	return n.GetHostSystemctlPath(), []string{"is-active", n.GetHostSystemdUnitName()}
 }
 
 func isRemotePIDRunning(runner Runner, pidPath string) bool {

internal/nginx/runner_ssh.go

@@ -74,10 +74,6 @@ func buildSSHOptions() hostssh.ClientOptions {
 	_ = n.HostPasswordRef // suppress unused-field lint until decryption lands
 
 	sudo := n.GetHostSudoPrefix()
-	systemctl := n.HostSystemctlPath
-	if systemctl == "" {
-		systemctl = "/bin/systemctl"
-	}
 
 	return hostssh.ClientOptions{
 		Address:        n.HostAddress,
@@ -88,7 +84,7 @@ func buildSSHOptions() hostssh.ClientOptions {
 		KnownHosts:     kh,
 		Config: hostssh.Config{
 			SudoPrefix:    sudo,
-			SystemctlPath: systemctl,
+			SystemctlPath: n.GetHostSystemctlPath(),
 			// The resolved path must match what -t/-T is invoked with, or the
 			// sudo whitelist check in needsSudo never fires.
 			NginxSbinPath: n.GetHostSbinPath(),

settings/nginx.go

@@ -23,6 +23,11 @@ const (
 	// same paths when SbinPath is left empty.
 	DefaultHostSbinPathSystemd = "/usr/sbin/nginx"
 	DefaultHostSbinPathLaunchd = "/opt/homebrew/opt/nginx/bin/nginx"
+
+	// Default systemd control paths on an SSH host, used whenever the
+	// corresponding setting is left empty.
+	DefaultHostSystemctlPath   = "/bin/systemctl"
+	DefaultHostSystemdUnitName = "nginx.service"
 )
 
 const DefaultMaintenanceDir = "/etc/nginx/maintenance"
@@ -141,6 +146,23 @@ func (n *Nginx) GetHostSudoPrefix() string {
 	return n.HostSudoPrefix
 }
 
+// GetHostSystemctlPath returns the systemctl binary to run on the SSH host.
+func (n *Nginx) GetHostSystemctlPath() string {
+	if n.HostSystemctlPath == "" {
+		return DefaultHostSystemctlPath
+	}
+	return n.HostSystemctlPath
+}
+
+// GetHostSystemdUnitName returns the systemd unit that manages nginx on the
+// SSH host.
+func (n *Nginx) GetHostSystemdUnitName() string {
+	if n.HostSystemdUnitName == "" {
+		return DefaultHostSystemdUnitName
+	}
+	return n.HostSystemdUnitName
+}
+
 func (n *Nginx) GetHostLaunchdService() string {
 	if n.HostLaunchdService == "" {
 		return "homebrew.mxcl.nginx"

settings/nginx_test.go

@@ -62,3 +62,27 @@ func TestNginx_GetHostSbinPath(t *testing.T) {
 		})
 	}
 }
+
+func TestNginx_GetHostSystemdDefaults(t *testing.T) {
+	tests := []struct {
+		name          string
+		nginx         Nginx
+		wantSystemctl string
+		wantUnit      string
+	}{
+		{"defaults", Nginx{}, DefaultHostSystemctlPath, DefaultHostSystemdUnitName},
+		{"configured systemctl", Nginx{HostSystemctlPath: "/usr/bin/systemctl"}, "/usr/bin/systemctl", DefaultHostSystemdUnitName},
+		{"configured unit", Nginx{HostSystemdUnitName: "openresty.service"}, DefaultHostSystemctlPath, "openresty.service"},
+		{"both configured", Nginx{HostSystemctlPath: "/usr/bin/systemctl", HostSystemdUnitName: "openresty.service"}, "/usr/bin/systemctl", "openresty.service"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.nginx.GetHostSystemctlPath(); got != tt.wantSystemctl {
+				t.Errorf("GetHostSystemctlPath() = %q, want %q", got, tt.wantSystemctl)
+			}
+			if got := tt.nginx.GetHostSystemdUnitName(); got != tt.wantUnit {
+				t.Errorf("GetHostSystemdUnitName() = %q, want %q", got, tt.wantUnit)
+			}
+		})
+	}
+}