Automation helper: Restructure application module

Avoid defining the endpoints within the application factory function. Instead,
define them outside and only register them in the application factory.
Furthermore, we store all dependencies of the application in a dedicated
structure that is accessible via the `request` object in the endpoints.

Change-Id: I6caf6baae877d5c5d0d488b1e28e283c3e29fb61

cmk/base/automation_helper/__init__.py

@@ -11,12 +11,18 @@
 
 from cmk.ccc.daemon import daemonize
 
+from cmk.utils.caching import cache_manager
 from cmk.utils.paths import omd_root
 from cmk.utils.redis import get_redis_client
 
+from cmk.base import config
+from cmk.base.api.agent_based.register import (
+    extract_known_discovery_rulesets,
+    get_previously_loaded_plugins,
+)
 from cmk.base.automations import automations
 
-from ._app import clear_caches_before_each_call, get_application, reload_automation_config
+from ._app import make_application
 from ._cache import Cache
 from ._config import config_from_disk_or_default_config
 from ._log import configure_logger, LOGGER
@@ -46,13 +52,6 @@ def main() -> int:
             run_directory=run_directory,
             log_directory=log_directory,
         )
-        app = get_application(
-            engine=automations,
-            cache=cache,
-            reloader_config=config.reloader_config,
-            reload_config=reload_automation_config,
-            clear_caches_before_each_call=clear_caches_before_each_call,
-        )
 
         daemonize()
 
@@ -63,7 +62,13 @@ def main() -> int:
             try:
                 run_server(
                     config.server_config,
-                    app,
+                    make_application(
+                        engine=automations,
+                        cache=cache,
+                        reloader_config=config.reloader_config,
+                        reload_config=_reload_automation_config,
+                        clear_caches_before_each_call=_clear_caches_before_each_call,
+                    ),
                 )
             except SystemExit:
                 LOGGER.info("Received termination signal, shutting down")
@@ -72,3 +77,14 @@ def main() -> int:
         return 1
 
     return 0
+
+
+def _reload_automation_config() -> None:
+    cache_manager.clear()
+    plugins = get_previously_loaded_plugins()
+    discovery_rulesets = extract_known_discovery_rulesets(plugins)
+    config.load(discovery_rulesets, validate_hosts=False)
+
+
+def _clear_caches_before_each_call() -> None:
+    config.get_config_cache().ruleset_matcher.clear_caches()