cmd/mapresponses: add mini tool to inspect mapresp state from integration

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

cmd/mapresponses/main.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/creachadair/command"
+	"github.com/creachadair/flax"
+	"github.com/juanfont/headscale/hscontrol/mapper"
+	"github.com/juanfont/headscale/integration/integrationutil"
+)
+
+type MapConfig struct {
+	Directory string `flag:"directory,Directory to read map responses from"`
+}
+
+var mapConfig MapConfig
+
+func main() {
+	root := command.C{
+		Name: "mapresponses",
+		Help: "MapResponses is a tool to map and compare map responses from a directory",
+		Commands: []*command.C{
+			{
+				Name:     "online",
+				Help:     "",
+				Usage:    "run [test-pattern] [flags]",
+				SetFlags: command.Flags(flax.MustBind, &mapConfig),
+				Run:      runOnline,
+			},
+			command.HelpCommand(nil),
+		},
+	}
+
+	env := root.NewEnv(nil).MergeFlags(true)
+	command.RunOrFail(env, os.Args[1:])
+}
+
+// runIntegrationTest executes the integration test workflow.
+func runOnline(env *command.Env) error {
+	if mapConfig.Directory == "" {
+		return fmt.Errorf("directory is required")
+	}
+
+	resps, err := mapper.ReadMapResponsesFromDirectory(mapConfig.Directory)
+	if err != nil {
+		return fmt.Errorf("reading map responses from directory: %w", err)
+	}
+
+	expected := integrationutil.BuildExpectedOnlineMap(resps)
+
+	out, err := json.MarshalIndent(expected, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshaling expected online map: %w", err)
+	}
+
+	os.Stderr.Write(out)
+	os.Stderr.Write([]byte("\n"))
+	return nil
+}