provide Admin API to inspect and delete contexts

Author: dirkbolte

README.md

@@ -1243,13 +1243,28 @@ For any kind of usage with parallel write requests, it's recommended to use a di
 
 # Debugging
 
+## Logging and responses
+
 In general, you can increase verbosity, either by [register a notifier](https://wiremock.org/3.x/docs/configuration/#notification-logging)
 and setting `verbose=true` or starting WireMock standalone (or docker) with `verbose=true`.
 
 - EventListeners and Matchers report errors with WireMock-internal exceptions. Additionally, errors are logged.
-  In order to see them, [register a notifier](https://wiremock.org/3.x/docs/configuration/#notification-logging).
+  For to see them, [register a notifier](https://wiremock.org/3.x/docs/configuration/#notification-logging).
 - Response templating errors are printed in the actual response body.
-- Various actions and decisions of this extensions are logged on info level, along with the context they are happening in.
+- Various actions and decisions of this extension are logged on info level, along with the context they are happening in.
+
+## Admin API
+
+The extension provides an admin API endpoint to retrieve the current state of the context store as well as to delete contexts:
+
+| Endpoint                                      | Method | Description                                                                             | Example                                                |
+|-----------------------------------------------|--------|-----------------------------------------------------------------------------------------|--------------------------------------------------------|
+| `/__admin/state-extension/contexts`           | GET    | Retrieves all context names (or an empty list if there are none). Always returns `200`. | `GET http://localhost:8080/__admin/state`              |
+| `/__admin/state-extension/contexts/{context}` | GET    | Retrieve internal structure of a context. Returns `404` if the context does not exist.  | `GET http://localhost:8080/__admin/state/myContext`    |
+| `/__admin/state-extension/contexts`           | DELETE | Deletes all contexts. Always returns `204`.                                             | `DELETE http://localhost:8080/__admin/state`           |
+| `/__admin/state-extension/contexts/{context}` | DELETE | Deletes a single context. Always returns `204`.                                         | `DELETE http://localhost:8080/__admin/state/myContext` |
+
+**Note:** The admin API intentionally does not provide `PUT` or `POST` methods for security and stability reasons.
 
 # Examples
 

src/main/java/org/wiremock/extensions/state/StateExtension.java

@@ -21,6 +21,7 @@
 import com.github.tomakehurst.wiremock.store.Store;
 import org.wiremock.extensions.state.extensions.DeleteStateEventListener;
 import org.wiremock.extensions.state.extensions.RecordStateEventListener;
+import org.wiremock.extensions.state.extensions.StateAdminApiExtension;
 import org.wiremock.extensions.state.extensions.requestmatcher.StateRequestMatcher;
 import org.wiremock.extensions.state.extensions.StateTemplateHelperProviderExtension;
 import org.wiremock.extensions.state.extensions.TransactionEventListener;
@@ -64,13 +65,15 @@ public List<Extension> create(WireMockServices services) {
         var deleteStateEventListener = new DeleteStateEventListener(contextManager, services);
         var transactionEventListener = new TransactionEventListener(transactionManager);
         var stateRequestMatcher = new StateRequestMatcher(contextManager, services);
+        var adminApiExtension = new StateAdminApiExtension(contextManager, services);
 
         return List.of(
             recordStateEventListener,
             deleteStateEventListener,
             transactionEventListener,
             stateRequestMatcher,
-            stateTemplateHelperProviderExtension
+            stateTemplateHelperProviderExtension,
+            adminApiExtension
         );
     }
 }

src/main/java/org/wiremock/extensions/state/extensions/StateAdminApiExtension.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2023 Dirk Bolte
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.wiremock.extensions.state.extensions;
+
+import com.github.tomakehurst.wiremock.admin.AdminTask;
+import com.github.tomakehurst.wiremock.admin.Router;
+import com.github.tomakehurst.wiremock.extension.AdminApiExtension;
+import com.github.tomakehurst.wiremock.extension.WireMockServices;
+import com.github.tomakehurst.wiremock.http.RequestMethod;
+import com.github.tomakehurst.wiremock.http.ResponseDefinition;
+import org.wiremock.extensions.state.internal.ContextManager;
+import org.wiremock.extensions.state.internal.StateExtensionMixin;
+import org.wiremock.extensions.state.internal.model.Context;
+
+import java.util.Optional;
+import java.util.UUID;
+
+/**
+ * ADMIN API extension to show and manage context contents.
+ * <p>
+ * DO NOT REGISTER directly. Use {@link org.wiremock.extensions.state.StateExtension} instead.
+ *
+ * @see org.wiremock.extensions.state.StateExtension
+ */
+public class StateAdminApiExtension implements AdminApiExtension, StateExtensionMixin {
+
+    private final WireMockServices wireMockServices;
+    private final ContextManager contextManager;
+
+
+    public StateAdminApiExtension(ContextManager contextManager, WireMockServices services) {
+        this.contextManager = contextManager;
+        this.wireMockServices = services;
+    }
+
+    @Override
+    public String getName() {
+        return "stateAdminApi";
+    }
+
+
+    @Override
+    public void contributeAdminApiRoutes(Router router) {
+        router.add(RequestMethod.GET, createPath("contexts"), getContexts());
+        router.add(RequestMethod.GET, createPath("contexts/{context}"), getContext());
+        router.add(RequestMethod.DELETE, createPath("contexts/{context}"), deleteContext());
+
+    }
+
+    private AdminTask getContexts() {
+        return (admin, serveEvent, pathParams) -> ResponseDefinition.okForJson(contextManager.getAllContextNames());
+    }
+
+    private AdminTask getContext() {
+        return (admin, serveEvent, pathParams) -> {
+            Optional<Context> context = contextManager.getContextCopy(pathParams.get("context"));
+            return context.map(ResponseDefinition::okForJson).orElseGet(ResponseDefinition::notFound);
+        };
+    }
+
+    private AdminTask deleteContext() {
+        return (admin, serveEvent, pathParams) -> {
+            contextManager.deleteContext(UUID.randomUUID().toString(), pathParams.get("context"));
+            return ResponseDefinition.noContent();
+        };
+    }
+
+    private String createPath(String path) {
+        return String.format("/state-extension/%s", path);
+    }
+}

src/main/java/org/wiremock/extensions/state/internal/ContextManager.java

@@ -19,10 +19,12 @@
 import org.wiremock.extensions.state.internal.model.Context;
 
 import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
+import java.util.stream.Collectors;
 
 import static org.wiremock.extensions.state.internal.ExtensionLogger.logger;
 
@@ -44,6 +46,17 @@ private static Supplier<Context> createNewContext(String contextName) {
         };
     }
 
+    /**
+     *
+     */
+    public List<String> getAllContextNames() {
+        return store
+            .getAllKeys()
+            .filter((it) -> it.startsWith(CONTEXT_KEY_PREFIX))
+            .map((it) -> it.replace(CONTEXT_KEY_PREFIX, ""))
+            .collect(Collectors.toList());
+    }
+
     /**
      * Searches for the context by the given name.
      *