fix: networking / services / and testing

internal/modules/networking/module.go

@@ -32,7 +32,7 @@ func (m *Module) Permissions() []rbac.Permission {
 }
 
 func (m *Module) Register(api huma.API) {
-	registerReads(api)
+	registerReads(api, m)
 	registerWrites(api, m)
 	registerHosts(api)
 }

internal/modules/networking/networking_handler_test.go

@@ -87,6 +87,30 @@ func TestNetworkingHandlers(t *testing.T) {
 		t.Errorf("list interfaces: got %d, want %d", resp.Code, http.StatusOK)
 	}
 
+	// 1b. Test GET /api/networking/interfaces/{name} (used by edit-form prefill).
+	// Asserts the backend's Snapshot output is returned verbatim as the body, so
+	// the same shape can feed straight into PUT.
+	resp = api.Get("/api/networking/interfaces/eth0")
+	if resp.Code != http.StatusOK {
+		t.Errorf("get interface: got %d, want %d", resp.Code, http.StatusOK)
+	}
+	var ifaceRes GetInterfaceConfigOutput
+	if err := json.Unmarshal(resp.Body.Bytes(), &ifaceRes.Body); err != nil {
+		t.Fatal(err)
+	}
+	if ifaceRes.Body.Method != "dhcp" || ifaceRes.Body.Address != "192.168.1.10/24" {
+		t.Errorf("get interface: got %+v, want snapshot result", ifaceRes.Body)
+	}
+
+	// Same endpoint with no backend should return 501.
+	noBackend := &Module{}
+	noBackendMux := http.NewServeMux()
+	noBackendAPI := humatest.Wrap(t, humago.New(noBackendMux, huma.DefaultConfig("Test", "1.0.0")))
+	noBackend.Register(noBackendAPI)
+	if got := noBackendAPI.Get("/api/networking/interfaces/eth0").Code; got != http.StatusNotImplemented {
+		t.Errorf("get interface without backend: got %d, want 501", got)
+	}
+
 	// 2. Test GET /api/networking/routes
 	resp = api.Get("/api/networking/routes")
 	if resp.Code != http.StatusOK {

internal/modules/networking/read.go

@@ -53,7 +53,47 @@ type DNSOutput struct {
 	}
 }
 
-func registerReads(api huma.API) {
+// GetInterfaceConfigInput carries the path param; matches the PUT endpoint's
+// IfacePathInput so the frontend can use the same path for both verbs.
+type GetInterfaceConfigInput struct {
+	Name string `path:"name" example:"eth0" doc:"Interface name"`
+}
+
+// GetInterfaceConfigOutput returns the same IfaceConfig shape that PUT
+// accepts, so the form can be pre-filled directly from this response.
+type GetInterfaceConfigOutput struct {
+	Body IfaceConfig
+}
+
+func registerReads(api huma.API, m *Module) {
+	huma.Register(api, huma.Operation{
+		OperationID: "networking-get-interface",
+		Method:      "GET",
+		Path:        "/api/networking/interfaces/{name}",
+		Summary:     "Get an interface's current configuration",
+		Description: "Returns the IfaceConfig the backend currently has for this " +
+			"interface (method, address/prefix, gateway, DNS, IPv6). Same schema as " +
+			"PUT /api/networking/interfaces/{name}, so the frontend can prefill an " +
+			"edit form from this response directly. Returns 501 when no backend was " +
+			"detected (nmcli / networkd / ifupdown).",
+		Tags:     []string{tagNetworking},
+		Metadata: op("read"),
+		Errors:   readErrors,
+	}, func(ctx context.Context, in *GetInterfaceConfigInput) (*GetInterfaceConfigOutput, error) {
+		if m.be == nil {
+			return nil, huma.Error501NotImplemented("", errNoBackend)
+		}
+		if err := validateIface(in.Name); err != nil {
+			return nil, err
+		}
+		cfg, err := m.be.Snapshot(ctx, in.Name)
+		if err != nil {
+			return nil, huma.Error500InternalServerError("snapshot failed", err)
+		}
+		return &GetInterfaceConfigOutput{Body: cfg}, nil
+	})
+
+
 	huma.Register(api, huma.Operation{
 		OperationID: "networking-list-interfaces",
 		Method:      "GET",

internal/modules/services/services.go

@@ -3,14 +3,22 @@ package services
 import (
 	"context"
 	"encoding/json"
+	"os/exec"
 	"regexp"
 	"strings"
+	"syscall"
 
 	"nadir/internal/oscmd"
 
 	"github.com/danielgtaylor/huma/v2"
 )
 
+// selfUnit is nadir's own systemd unit name. Acting on it via the normal
+// synchronous path would have systemd SIGTERM the very process serving the
+// request, so the client sees a dropped connection / 500 even though the
+// action succeeded. We detach those calls into a Setsid subprocess instead.
+const selfUnit = "nadir"
+
 const tagServices = "Services"
 
 var (
@@ -136,6 +144,9 @@ func registerServices(api huma.API) {
 			if err := ensureExists(in.Unit); err != nil {
 				return nil, err
 			}
+			if isSelf(in.Unit) {
+				return runDetached(c.action, in.Unit)
+			}
 			if _, err := oscmd.Run("systemctl", c.action, "--", in.Unit); err != nil {
 				return nil, huma.Error500InternalServerError("systemctl "+c.action+" failed", err)
 			}
@@ -144,6 +155,27 @@ func registerServices(api huma.API) {
 	}
 }
 
+// isSelf reports whether unit names nadir's own service, with or without the
+// .service suffix.
+func isSelf(unit string) bool {
+	return unit == selfUnit || unit == selfUnit+".service"
+}
+
+// runDetached fires systemctl in a new session so a "systemctl restart nadir"
+// (or stop) doesn't kill its own caller before the HTTP response is written.
+// Returns success once the subprocess has *started* — the actual systemd
+// operation may complete after the response is sent, which is the whole point.
+func runDetached(action, unit string) (*oscmd.StatusOutput, error) {
+	cmd := exec.Command("systemctl", action, "--", unit)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+	if err := cmd.Start(); err != nil {
+		return nil, huma.Error500InternalServerError("could not start detached systemctl", err)
+	}
+	// Reap in the background so the child doesn't become a zombie.
+	go cmd.Wait()
+	return oscmd.OK(), nil
+}
+
 // validateUnit guards against empty, flag-like, or malformed unit names.
 func validateUnit(unit string) error {
 	if unit == "" || strings.HasPrefix(unit, "-") || !unitNameRe.MatchString(unit) {

internal/modules/services/services_test.go

@@ -19,3 +19,22 @@ func TestValidateUnit(t *testing.T) {
 		}
 	}
 }
+
+// TestIsSelf pins the dispatch that detaches stop/restart-of-self into a
+// Setsid subprocess. Both "nadir" and "nadir.service" must match; anything
+// else (including substrings) must not, or unrelated services would also get
+// detached and bypass the synchronous error path.
+func TestIsSelf(t *testing.T) {
+	yes := []string{"nadir", "nadir.service"}
+	for _, u := range yes {
+		if !isSelf(u) {
+			t.Errorf("isSelf(%q) = false, want true", u)
+		}
+	}
+	no := []string{"", "sshd.service", "nadir-something.service", "nadir.timer", "not-nadir.service"}
+	for _, u := range no {
+		if isSelf(u) {
+			t.Errorf("isSelf(%q) = true, want false", u)
+		}
+	}
+}