Merge pull request #553 from nscuro/request-id-filter

Add filter to track request ID

alpine-server/src/main/java/alpine/server/filters/RequestIdFilter.java

@@ -0,0 +1,59 @@
+/*
+ * This file is part of Alpine.
+ *
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (c) Steve Springett. All Rights Reserved.
+ */
+package alpine.server.filters;
+
+import org.slf4j.MDC;
+
+import javax.annotation.Priority;
+import javax.ws.rs.container.ContainerRequestContext;
+import javax.ws.rs.container.ContainerRequestFilter;
+import javax.ws.rs.container.ContainerResponseContext;
+import javax.ws.rs.container.ContainerResponseFilter;
+import javax.ws.rs.ext.Provider;
+import java.io.IOException;
+import java.util.UUID;
+import java.util.regex.Pattern;
+
+@Provider
+@Priority(1)
+public class RequestIdFilter implements ContainerRequestFilter, ContainerResponseFilter {
+
+    private static final Pattern REQUEST_ID_PATTERN = Pattern.compile("^[A-Za-z0-9._\\-=+]{16,192}$");
+
+    @Override
+    public void filter(final ContainerRequestContext requestContext) throws IOException {
+        String requestId = requestContext.getHeaderString("X-Request-Id");
+        if (requestId == null || !REQUEST_ID_PATTERN.matcher(requestId).matches()) {
+            requestId = UUID.randomUUID().toString();
+        }
+
+        requestContext.setProperty("requestId", requestId);
+        MDC.put("requestId", requestId);
+    }
+
+    @Override
+    public void filter(final ContainerRequestContext requestContext, final ContainerResponseContext responseContext) throws IOException {
+        if (requestContext.getProperty("requestId") instanceof final String requestId) {
+            responseContext.getHeaders().putSingle("X-Request-Id", requestId);
+        }
+
+        MDC.remove("requestId");
+    }
+
+}

alpine-server/src/test/java/alpine/server/filters/RequestIdFilterTest.java

@@ -0,0 +1,98 @@
+/*
+ * This file is part of Alpine.
+ *
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (c) Steve Springett. All Rights Reserved.
+ */
+package alpine.server.filters;
+
+import org.assertj.core.api.SoftAssertions;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mockito;
+
+import javax.ws.rs.container.ContainerRequestContext;
+import javax.ws.rs.container.ContainerResponseContext;
+import javax.ws.rs.core.MultivaluedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+public class RequestIdFilterTest {
+
+    private RequestIdFilter requestIdFilter;
+    private ContainerRequestContext requestContextMock;
+    private ContainerResponseContext responseContextMock;
+
+    @Before
+    public void setUp() {
+        requestIdFilter = new RequestIdFilter();
+        requestContextMock = mock(ContainerRequestContext.class);
+        responseContextMock = mock(ContainerResponseContext.class);
+    }
+
+    @Test
+    public void testProvidedRequestId() throws Exception {
+        final Map<String, Boolean> testCases = Map.ofEntries(
+                Map.entry("a".repeat(15), false),
+                Map.entry("a".repeat(16), true),
+                Map.entry("a".repeat(192), true),
+                Map.entry("a".repeat(193), false),
+                Map.entry("Zm9vYmFyYmF6cXV4cXV1eA==", true),
+                Map.entry("112bfb53-eb65-41b5-a093-b73902f43447", true),
+                Map.entry("foo%24bar%40baz%C2%A7", false)
+        );
+
+        final var softAssertions = new SoftAssertions();
+        for (final  Map.Entry<String, Boolean> entry : testCases.entrySet()) {
+            final String providedRequestId = entry.getKey();
+            final boolean shouldTakeProvidedRequestId = entry.getValue();
+
+            doReturn(providedRequestId).when(requestContextMock).getHeaderString(eq("X-Request-Id"));
+            requestIdFilter.filter(requestContextMock);
+
+            final ArgumentCaptor<String> requestIdCaptor = ArgumentCaptor.forClass(String.class);
+            verify(requestContextMock).setProperty(eq("requestId"), requestIdCaptor.capture());
+            Mockito.reset(requestContextMock);
+
+            if (shouldTakeProvidedRequestId) {
+                softAssertions.assertThat(requestIdCaptor.getValue()).isEqualTo(providedRequestId);
+            } else {
+                softAssertions.assertThat(requestIdCaptor.getValue())
+                        .matches("^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$");
+            }
+        }
+
+        softAssertions.assertAll();
+    }
+
+    @Test
+    public void testResponseHeader() throws Exception {
+        final var headers = new MultivaluedHashMap<String, Object>();
+        doReturn(headers).when(responseContextMock).getHeaders();
+
+        doReturn("foobarbazquxquux").when(requestContextMock).getProperty("requestId");
+        requestIdFilter.filter(requestContextMock, responseContextMock);
+
+        assertThat(headers).containsEntry("X-Request-Id", List.of("foobarbazquxquux"));
+    }
+
+}