host daemon touches (#4)

* feat: launch config tests

* feat: readiness probe port alignment

internal/firecracker/configure_test.go

@@ -0,0 +1,104 @@
+package firecracker
+
+import (
+	"context"
+	"io"
+	"net"
+	"net/http"
+	"path/filepath"
+	"testing"
+)
+
+type capturedRequest struct {
+	Method string
+	Path   string
+	Body   string
+}
+
+func TestConfigureMachineEnablesEntropyAndSerialBeforeStart(t *testing.T) {
+	var requests []capturedRequest
+
+	socketPath, shutdown := startUnixSocketServer(t, func(w http.ResponseWriter, r *http.Request) {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			t.Fatalf("read request body: %v", err)
+		}
+
+		requests = append(requests, capturedRequest{
+			Method: r.Method,
+			Path:   r.URL.Path,
+			Body:   string(body),
+		})
+		w.WriteHeader(http.StatusNoContent)
+	})
+	defer shutdown()
+
+	client := newAPIClient(socketPath)
+	spec := MachineSpec{
+		ID:              "vm-1",
+		VCPUs:           1,
+		MemoryMiB:       512,
+		KernelImagePath: "/kernel",
+		RootFSPath:      "/rootfs",
+	}
+	paths := machinePaths{
+		JailedSerialLogPath: "/logs/serial.log",
+	}
+	network := NetworkAllocation{
+		InterfaceID: defaultInterfaceID,
+		TapName:     "fctap0",
+		GuestMAC:    "06:00:ac:10:00:02",
+	}
+
+	if err := configureMachine(context.Background(), client, paths, spec, network); err != nil {
+		t.Fatalf("configure machine: %v", err)
+	}
+
+	gotPaths := make([]string, 0, len(requests))
+	for _, request := range requests {
+		gotPaths = append(gotPaths, request.Path)
+	}
+	wantPaths := []string{
+		"/machine-config",
+		"/boot-source",
+		"/drives/root_drive",
+		"/network-interfaces/net0",
+		"/entropy",
+		"/serial",
+		"/actions",
+	}
+	if len(gotPaths) != len(wantPaths) {
+		t.Fatalf("request count mismatch: got %d want %d (%v)", len(gotPaths), len(wantPaths), gotPaths)
+	}
+	for i := range wantPaths {
+		if gotPaths[i] != wantPaths[i] {
+			t.Fatalf("request %d mismatch: got %q want %q", i, gotPaths[i], wantPaths[i])
+		}
+	}
+	if requests[4].Body != "{}" {
+		t.Fatalf("entropy body mismatch: got %q", requests[4].Body)
+	}
+	if requests[5].Body != "{\"serial_out_path\":\"/logs/serial.log\"}" {
+		t.Fatalf("serial body mismatch: got %q", requests[5].Body)
+	}
+}
+
+func startUnixSocketServer(t *testing.T, handler http.HandlerFunc) (string, func()) {
+	t.Helper()
+
+	socketPath := filepath.Join(t.TempDir(), "firecracker.sock")
+	listener, err := net.Listen("unix", socketPath)
+	if err != nil {
+		t.Fatalf("listen on unix socket: %v", err)
+	}
+
+	server := &http.Server{Handler: handler}
+	go func() {
+		_ = server.Serve(listener)
+	}()
+
+	return socketPath, func() {
+		_ = server.Shutdown(context.Background())
+		_ = listener.Close()
+	}
+}