Added PrometheusHandler

2 files changed, 210 insertions, 0 deletions

diff --git a/container-core/src/main/java/com/yahoo/container/handler/metrics/PrometheusHandler.java b/container-core/src/main/java/com/yahoo/container/handler/metrics/PrometheusHandler.java
new file mode 100644
index 00000000000..e6683583ca6
--- /dev/null
+++ b/container-core/src/main/java/com/yahoo/container/handler/metrics/PrometheusHandler.java
@@ -0,0 +1,67 @@
+package com.yahoo.container.handler.metrics;
+
+import ai.vespa.util.http.VespaHttpClientBuilder;
+import com.yahoo.container.jdisc.HttpResponse;
+import com.yahoo.restapi.Path;
+import com.yahoo.restapi.StringResponse;
+import com.yahoo.vespa.jdk8compat.List;
+import com.yahoo.yolean.Exceptions;
+import java.io.IOException;
+import java.net.URI;
+import java.util.Optional;
+import java.util.concurrent.Executor;
+import org.apache.http.client.HttpClient;
+import org.apache.http.client.config.RequestConfig;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.BasicResponseHandler;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.eclipse.jetty.server.Response;
+
+import static com.yahoo.container.handler.metrics.MetricsV2Handler.consumerQuery;
+import static com.yahoo.jdisc.Response.Status.INTERNAL_SERVER_ERROR;
+
+public class PrometheusHandler extends HttpHandlerBase{
+
+    public static final String V1_PATH = "/prometheus/v1";
+    static final String VALUES_PATH = V1_PATH + "/values";
+
+    private static final int HTTP_CONNECT_TIMEOUT = 5000;
+    private static final int HTTP_SOCKET_TIMEOUT = 30000;
+
+    private final String prometheusProxyUri;
+    private final HttpClient httpClient = createHttpClient();
+
+    protected PrometheusHandler(Executor executor,
+                                MetricsProxyApiConfig config) {
+        super(executor);
+        prometheusProxyUri = "http://localhost:" + config.prometheusPort() + config.prometheusApiPath();
+    }
+
+    @Override
+    protected Optional<HttpResponse> doHandle(URI requestUri, Path apiPath, String consumer) {
+        if (apiPath.matches(V1_PATH)) return Optional.of(resourceListResponse(requestUri, List.of(VALUES_PATH)));
+        if (apiPath.matches(VALUES_PATH)) return Optional.of(valuesResponse(consumer));
+        return Optional.empty();
+    }
+
+    private HttpResponse valuesResponse(String consumer) {
+        try {
+            String uri = prometheusProxyUri + consumerQuery(consumer);
+            String prometheusText = httpClient.execute(new HttpGet(uri), new BasicResponseHandler())
+            return new StringResponse(prometheusText);
+        } catch (IOException e) {
+            log.warning("Unable to retrieve metrics from " + metricsProxyUri + ": " + Exceptions.toMessageString(e));
+            return new ErrorResponse(INTERNAL_SERVER_ERROR, e.getMessage());
+        }
+    }
+
+    private static CloseableHttpClient createHttpClient() {
+        return VespaHttpClientBuilder.create()
+                .setUserAgent("application-prometheus-receiver")
+                .setDefaultRequestConfig(RequestConfig.custom()
+                                            .setConnectTimeout(HTTP_CONNECT_TIMEOUT)
+                                            .setSocketTimeout(HTTP_SOCKET_TIMEOUT)
+                                            .build())
+                .build();
+    }
+}
diff --git a/container-core/src/test/java/com/yahoo/container/handler/metrics/PrometheusHandlerTest.java b/container-core/src/test/java/com/yahoo/container/handler/metrics/PrometheusHandlerTest.java
new file mode 100644
index 00000000000..350c038602e
--- /dev/null
+++ b/container-core/src/test/java/com/yahoo/container/handler/metrics/PrometheusHandlerTest.java
@@ -0,0 +1,143 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.handler.metrics;
+
+import com.github.tomakehurst.wiremock.junit.WireMockRule;
+import com.yahoo.container.jdisc.RequestHandlerTestDriver;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
+import static com.github.tomakehurst.wiremock.client.WireMock.equalTo;
+import static com.github.tomakehurst.wiremock.client.WireMock.get;
+import static com.github.tomakehurst.wiremock.client.WireMock.urlPathEqualTo;
+import static com.github.tomakehurst.wiremock.core.WireMockConfiguration.options;
+import static com.yahoo.container.handler.metrics.MetricsV2Handler.V2_PATH;
+import static com.yahoo.container.handler.metrics.MetricsV2Handler.VALUES_PATH;
+import static com.yahoo.container.handler.metrics.MetricsV2Handler.consumerQuery;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+/**
+ * @author gjoranv
+ */
+public class PrometheusHandlerTest {
+
+    private static final String URI_BASE = "http://localhost";
+
+    private static final String V2_URI = URI_BASE + Prometheus;
+    private static final String VALUES_URI = URI_BASE + VALUES_PATH;
+
+    // Mock applicationmetrics api
+    private static final String MOCK_METRICS_PATH = "/node0";
+
+    private static final String TEST_FILE = "application-metrics.json";
+    private static final String RESPONSE = getFileContents(TEST_FILE);
+    private static final String CPU_METRIC = "cpu.util";
+    private static final String REPLACED_CPU_METRIC = "replaced_cpu_util";
+    private static final String CUSTOM_CONSUMER = "custom-consumer";
+
+    private static RequestHandlerTestDriver testDriver;
+
+    @Rule
+    public WireMockRule wireMockRule = new WireMockRule(options().dynamicPort());
+
+    @Before
+    public void setup() {
+        setupWireMock();
+        var handler = new MetricsV2Handler(Executors.newSingleThreadExecutor(),
+                new MetricsProxyApiConfig.Builder()
+                        .metricsPort(wireMockRule.port())
+                        .metricsApiPath(MOCK_METRICS_PATH)
+                        .build());
+        testDriver = new RequestHandlerTestDriver(handler);
+    }
+
+    private void setupWireMock() {
+        wireMockRule.stubFor(get(urlPathEqualTo(MOCK_METRICS_PATH))
+                .willReturn(aResponse().withBody(RESPONSE)));
+
+        // Add a slightly different response for a custom consumer.
+        String myConsumerResponse = RESPONSE.replaceAll(CPU_METRIC, REPLACED_CPU_METRIC);
+        wireMockRule.stubFor(get(urlPathEqualTo(MOCK_METRICS_PATH))
+                .withQueryParam("consumer", equalTo(CUSTOM_CONSUMER))
+                .willReturn(aResponse().withBody(myConsumerResponse)));
+    }
+
+    @Test
+    public void v2_response_contains_values_uri() throws Exception {
+        String response = testDriver.sendRequest(V2_URI).readAll();
+        JSONObject root = new JSONObject(response);
+        assertTrue(root.has("resources"));
+
+        JSONArray resources = root.getJSONArray("resources");
+        assertEquals(1, resources.length());
+
+        JSONObject valuesUri = resources.getJSONObject(0);
+        assertEquals(VALUES_URI, valuesUri.getString("url"));
+    }
+
+    @Ignore
+    @Test
+    public void visually_inspect_values_response() throws Exception {
+        JSONObject responseJson = getResponseAsJson(null);
+        System.out.println(responseJson.toString(4));
+    }
+
+    @Test
+    public void invalid_path_yields_error_response() throws Exception {
+        String response = testDriver.sendRequest(V2_URI + "/invalid").readAll();
+        JSONObject root = new JSONObject(response);
+        assertTrue(root.has("error"));
+        assertTrue(root.getString("error" ).startsWith("No content"));
+    }
+
+    @Test
+    public void values_response_is_equal_to_test_file() {
+        String response = testDriver.sendRequest(VALUES_URI).readAll();
+        assertEquals(RESPONSE, response);
+    }
+
+    @Test
+    public void consumer_is_propagated_to_metrics_proxy_api() throws JSONException {
+        JSONObject responseJson = getResponseAsJson(CUSTOM_CONSUMER);
+
+        JSONObject firstNodeMetricsValues =
+                responseJson.getJSONArray("nodes").getJSONObject(0)
+                        .getJSONObject("node")
+                        .getJSONArray("metrics").getJSONObject(0)
+                        .getJSONObject("values");
+
+        assertTrue(firstNodeMetricsValues.has(REPLACED_CPU_METRIC));
+    }
+
+    private JSONObject getResponseAsJson(String consumer) {
+        String response = testDriver.sendRequest(VALUES_URI + consumerQuery(consumer)).readAll();
+        try {
+            return new JSONObject(response);
+        } catch (JSONException e) {
+            fail("Failed to create json object: " + e.getMessage());
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static String getFileContents(String filename) {
+        InputStream in = MetricsV2HandlerTest.class.getClassLoader().getResourceAsStream(filename);
+        if (in == null) {
+            throw new RuntimeException("File not found: " + filename);
+        }
+        return new BufferedReader(new InputStreamReader(in)).lines().collect(Collectors.joining("\n"));
+    }
+
+}