feat: add config write API (POST /api/0/config, POST /api/0/config/rollback)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

hbd/server/http.py

@@ -1075,6 +1075,92 @@ async def start(
         backups = configio_mod.list_backups(_config_path)
         return web.json_response({"backups": backups})
 
+    async def api_config_post(request):
+        """POST /api/0/config — publish staged changes to .hb.yaml. Admin only."""
+        user, err = _require_auth(request)
+        if err:
+            return err
+        if user and not user.admin:
+            return web.json_response({"error": "Forbidden"}, status=403)
+        if not _config_path:
+            return web.json_response({"error": "Config path not available"}, status=503)
+        try:
+            payload = await request.json()
+        except Exception:
+            return web.json_response({"error": "Invalid JSON"}, status=400)
+
+        try:
+            data = configio_mod.read_roundtrip(_config_path)
+
+            if "server" in payload:
+                configio_mod.apply_structured_section(data, "server", payload["server"])
+
+            if "users" in payload:
+                # Hash any plaintext passwords; preserve existing hashes when omitted or "•••"
+                existing_users = data.get("users") or {}
+                users_payload = payload["users"]
+                for username, attrs in users_payload.items():
+                    pw = attrs.get("password", "")
+                    if pw and pw != "•••" and not pw.startswith("pbkdf2:"):
+                        attrs["password"] = users_mod.hash_password(pw)
+                    elif not pw or pw == "•••":
+                        existing_hash = (existing_users.get(username) or {}).get("password", "")
+                        if existing_hash:
+                            attrs["password"] = existing_hash
+                        else:
+                            attrs.pop("password", None)
+                configio_mod.apply_structured_section(data, "users", users_payload)
+
+            if "oauth" in payload:
+                data["oauth"] = payload["oauth"]
+
+            for section in ("notification_channels", "thresholds", "hosts", "dns"):
+                if section in payload:
+                    configio_mod.apply_yaml_section(data, section, payload[section])
+
+            configio_mod.write_config(_config_path, data)
+        except Exception as exc:
+            logger.error("Config write failed: %s", exc)
+            return web.json_response({"error": str(exc)}, status=500)
+
+        if hasattr(config, "reload"):
+            await config.reload()
+        users_mod.load_users(config)
+
+        return web.json_response({"ok": True})
+
+    async def api_config_rollback(request):
+        """POST /api/0/config/rollback — restore a backup. Admin only."""
+        user, err = _require_auth(request)
+        if err:
+            return err
+        if user and not user.admin:
+            return web.json_response({"error": "Forbidden"}, status=403)
+        if not _config_path:
+            return web.json_response({"error": "Config path not available"}, status=503)
+        try:
+            body = await request.json()
+        except Exception:
+            return web.json_response({"error": "Invalid JSON"}, status=400)
+
+        backup = body.get("backup", "")
+        expected_prefix = _config_path + ".bak."
+        if not backup or not backup.startswith(expected_prefix) or not os.path.exists(backup):
+            return web.json_response({"error": "Invalid or missing backup"}, status=400)
+
+        try:
+            backup_data = configio_mod.read_roundtrip(backup)
+            configio_mod.write_config(_config_path, backup_data)
+        except Exception as exc:
+            logger.error("Rollback failed: %s", exc)
+            return web.json_response({"error": str(exc)}, status=500)
+
+        if hasattr(config, "reload"):
+            await config.reload()
+        users_mod.load_users(config)
+
+        return web.json_response({"ok": True})
+
     app = web.Application()
     app.add_routes(
         [
@@ -1096,6 +1182,8 @@ async def start(
             web.get("/api/0/config",                 api_config_get),
             web.get("/api/0/config/section/{name}",  api_config_section_get),
             web.get("/api/0/config/backups",         api_config_backups_get),
+            web.post("/api/0/config",                api_config_post),
+            web.post("/api/0/config/rollback",       api_config_rollback),
             # Hosts
             web.get("/api/0/hosts", api_hosts),
             web.get("/api/0/alert_summary", api_alert_summary),