Add Prometheus http api

13 files changed, 369 insertions, 7 deletions

diff --git a/metrics-proxy/pom.xml b/metrics-proxy/pom.xml
index 26caa3f66af..99354ee22e8 100644
--- a/metrics-proxy/pom.xml
+++ b/metrics-proxy/pom.xml
@@ -116,6 +116,14 @@
       <version>${project.version}</version>
     </dependency>
     <dependency>
+      <groupId>io.prometheus</groupId>
+      <artifactId>simpleclient</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.prometheus</groupId>
+      <artifactId>simpleclient_common</artifactId>
+    </dependency>
+    <dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpclient</artifactId>
     </dependency>
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ErrorResponse.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ErrorResponse.java
index daa69191506..d3296331a6a 100644
--- a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ErrorResponse.java
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ErrorResponse.java
@@ -15,12 +15,12 @@ import static java.util.logging.Level.WARNING;
 /**
  * @author gjoranv
  */
-class ErrorResponse extends JsonResponse {
+public class ErrorResponse extends JsonResponse {
     private static Logger log = Logger.getLogger(ErrorResponse.class.getName());
 
     private static ObjectMapper objectMapper = new ObjectMapper();
 
-    ErrorResponse(int code, String message) {
+    public ErrorResponse(int code, String message) {
         super(code, asErrorJson(message));
     }
 
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/JsonResponse.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/JsonResponse.java
index 758a043a823..9f31e9356e8 100644
--- a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/JsonResponse.java
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/JsonResponse.java
@@ -13,10 +13,10 @@ import java.nio.charset.Charset;
 /**
  * @author gjoranv
  */
-class JsonResponse extends HttpResponse {
+public class JsonResponse extends HttpResponse {
     private final byte[] data;
 
-    JsonResponse(int code, String data) {
+    public JsonResponse(int code, String data) {
         super(code);
         this.data = data.getBytes(Charset.forName(DEFAULT_CHARACTER_ENCODING));
     }
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/RestApiUtil.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/RestApiUtil.java
index 27411b5dbd9..9d9256e17e8 100644
--- a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/RestApiUtil.java
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/RestApiUtil.java
@@ -23,7 +23,7 @@ public class RestApiUtil {
     private static Logger log = Logger.getLogger(RestApiUtil.class.getName());
 
 
-    static JsonResponse resourceListResponse(URI requestUri, List<String> resources) {
+    public static JsonResponse resourceListResponse(URI requestUri, List<String> resources) {
         try {
             return new JsonResponse(OK, RestApiUtil.resourceList(requestUri, resources));
         } catch (JSONException e) {
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/TextResponse.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/TextResponse.java
new file mode 100644
index 00000000000..7dfc232d253
--- /dev/null
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/TextResponse.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.http;
+
+import com.yahoo.container.jdisc.HttpResponse;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.charset.Charset;
+
+/**
+ * @author yj-jtakagi
+ * @author gjoranv
+ */
+public class TextResponse extends HttpResponse {
+
+    private final byte[] data;
+
+    public TextResponse(int code, String data) {
+        super(code);
+        this.data = data.getBytes(Charset.forName(DEFAULT_CHARACTER_ENCODING));
+    }
+
+    @Override
+    public void render(OutputStream outputStream) throws IOException {
+        outputStream.write(data);
+    }
+
+}
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ValuesFetcher.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ValuesFetcher.java
index f99fe962f38..00f2078ef57 100644
--- a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ValuesFetcher.java
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/ValuesFetcher.java
@@ -33,7 +33,7 @@ public class ValuesFetcher {
     private final VespaServices vespaServices;
     private final MetricsConsumers metricsConsumers;
 
-    ValuesFetcher(MetricsManager metricsManager,
+    public ValuesFetcher(MetricsManager metricsManager,
                   VespaServices vespaServices,
                   MetricsConsumers metricsConsumers) {
         this.metricsManager = metricsManager;
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandler.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandler.java
new file mode 100644
index 00000000000..7c018ea6d85
--- /dev/null
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandler.java
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.http.prometheus;
+
+import ai.vespa.metricsproxy.core.MetricsConsumers;
+import ai.vespa.metricsproxy.core.MetricsManager;
+import ai.vespa.metricsproxy.http.ErrorResponse;
+import ai.vespa.metricsproxy.http.JsonResponse;
+import ai.vespa.metricsproxy.http.TextResponse;
+import ai.vespa.metricsproxy.http.ValuesFetcher;
+import ai.vespa.metricsproxy.metric.model.MetricsPacket;
+import ai.vespa.metricsproxy.metric.model.json.JsonRenderingException;
+import ai.vespa.metricsproxy.service.VespaServices;
+import com.google.inject.Inject;
+import com.yahoo.container.jdisc.HttpRequest;
+import com.yahoo.container.jdisc.HttpResponse;
+import com.yahoo.container.jdisc.ThreadedHttpRequestHandler;
+import com.yahoo.restapi.Path;
+
+import java.util.List;
+import java.util.concurrent.Executor;
+
+import static ai.vespa.metricsproxy.http.RestApiUtil.resourceListResponse;
+import static ai.vespa.metricsproxy.metric.model.prometheus.PrometheusUtil.toPrometheusModel;
+import static com.yahoo.jdisc.Response.Status.INTERNAL_SERVER_ERROR;
+import static com.yahoo.jdisc.Response.Status.METHOD_NOT_ALLOWED;
+import static com.yahoo.jdisc.Response.Status.NOT_FOUND;
+import static com.yahoo.jdisc.Response.Status.OK;
+import static com.yahoo.jdisc.http.HttpRequest.Method.GET;
+
+/**
+ * @author gjoranv
+ */
+public class PrometheusHandler extends ThreadedHttpRequestHandler {
+
+    static final String V1_PATH = "/prometheus/v1";
+    static final String VALUES_PATH = V1_PATH + "/values";
+
+    private final ValuesFetcher valuesFetcher;
+
+    @Inject
+    public PrometheusHandler(Executor executor,
+                             MetricsManager metricsManager,
+                             VespaServices vespaServices,
+                             MetricsConsumers metricsConsumers) {
+        super(executor);
+        valuesFetcher = new ValuesFetcher(metricsManager, vespaServices, metricsConsumers);
+    }
+
+    @Override
+    public HttpResponse handle(HttpRequest request) {
+        if (request.getMethod() != GET) return new JsonResponse(METHOD_NOT_ALLOWED, "Only GET is supported");
+
+        Path path = new Path(request.getUri());
+
+        if (path.matches(V1_PATH)) return resourceListResponse(request.getUri(), List.of(VALUES_PATH));
+        if (path.matches(VALUES_PATH)) return valuesResponse(request);
+
+        return new ErrorResponse(NOT_FOUND, "No content at given path");
+    }
+
+    private TextResponse valuesResponse(HttpRequest request) {
+        try {
+            List<MetricsPacket> metrics =  valuesFetcher.fetch(request.getProperty("consumer"));
+            return new TextResponse(OK, toPrometheusModel(metrics).serialize());
+        } catch (JsonRenderingException e) {
+            return new TextResponse(INTERNAL_SERVER_ERROR, e.getMessage());
+        }
+    }
+
+}
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusModel.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusModel.java
new file mode 100644
index 00000000000..83119a552f1
--- /dev/null
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusModel.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.metric.model.prometheus;
+
+import io.prometheus.client.Collector;
+import io.prometheus.client.exporter.common.TextFormat;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * @author yj-jtakagi
+ * @author gjoranv
+ */
+public class PrometheusModel implements Enumeration<Collector.MetricFamilySamples> {
+    private static Logger log = Logger.getLogger(PrometheusModel.class.getName());
+
+    private final Iterator<Collector.MetricFamilySamples> metricFamilySamplesIterator;
+
+    PrometheusModel(List<Collector.MetricFamilySamples> metricFamilySamples) {
+        this.metricFamilySamplesIterator = metricFamilySamples.iterator();
+    }
+
+    @Override
+    public boolean hasMoreElements() {
+        return metricFamilySamplesIterator.hasNext();
+    }
+
+    @Override
+    public Collector.MetricFamilySamples nextElement() {
+        return metricFamilySamplesIterator.next();
+    }
+
+    public String serialize() {
+        var writer = new StringWriter();
+        try {
+            TextFormat.write004(writer, this);
+        } catch (IOException e) {
+            log.log(Level.WARNING, "Got exception when rendering metrics:", e);
+            throw new PrometheusRenderingException("Could not render metrics. Check the log for details.");
+        }
+        return writer.toString();
+    }
+
+}
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusRenderingException.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusRenderingException.java
new file mode 100644
index 00000000000..68db7e64bfd
--- /dev/null
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusRenderingException.java
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.metric.model.prometheus;
+
+/**
+ * @author gjoranv
+ */
+public class PrometheusRenderingException extends RuntimeException {
+
+    PrometheusRenderingException(String message) {
+        super(message);
+    }
+
+}
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusUtil.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusUtil.java
new file mode 100644
index 00000000000..cbd4ad2ef8d
--- /dev/null
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusUtil.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.metric.model.prometheus;
+
+import ai.vespa.metricsproxy.metric.model.MetricsPacket;
+import ai.vespa.metricsproxy.metric.model.ServiceId;
+import io.prometheus.client.Collector;
+import io.prometheus.client.Collector.MetricFamilySamples;
+import io.prometheus.client.Collector.MetricFamilySamples.Sample;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+
+/**
+ * @author yj-jtakagi
+ * @author gjoranv
+ */
+public class PrometheusUtil {
+
+    public static PrometheusModel toPrometheusModel(List<MetricsPacket> metricsPackets) {
+        Map<ServiceId, List<MetricsPacket>> packetsByService = metricsPackets.stream()
+                .collect(Collectors.groupingBy(packet -> packet.service));
+
+        List<MetricFamilySamples> metricFamilySamples = new ArrayList<>(packetsByService.size());
+
+        packetsByService.forEach(((serviceId, packets) -> {
+            Map<String, List<Sample>> samples = new HashMap<>();
+
+            var serviceName = Collector.sanitizeMetricName(serviceId.id);
+            for (var packet : packets) {
+                var dimensions = packet.dimensions();
+                List<String> labels = new ArrayList<>(dimensions.size());
+                List<String> labelValues = new ArrayList<>(dimensions.size());
+                for (var entry : dimensions.entrySet()) {
+                    var labelName = Collector.sanitizeMetricName(entry.getKey().id);
+                    labels.add(labelName);
+                    labelValues.add(entry.getValue());
+                }
+
+                for (var metric : packet.metrics().entrySet()) {
+                    var metricName = serviceName + "_" + Collector.sanitizeMetricName(metric.getKey().id);
+                    List<Sample> sampleList;
+                    if (samples.containsKey(metricName)) {
+                        sampleList = samples.get(metricName);
+                    } else {
+                        sampleList = new ArrayList<>();
+                        samples.put(metricName, sampleList);
+                        metricFamilySamples.add(new MetricFamilySamples(metricName, Collector.Type.UNTYPED, "", sampleList));
+                    }
+                    sampleList.add(new Sample(metricName, labels, labelValues, metric.getValue().doubleValue(), packet.timestamp * 1000));
+                }
+            }
+            // convert status message to 0,1 metric
+            var firstPacket = packets.get(0);
+            String statusMetricName = serviceName + "_status";
+            // MetricsPacket status 0 means OK, but it's the opposite in Prometheus.
+            double statusMetricValue = (firstPacket.statusCode == 0) ? 1.0 : 0.0;
+            List<Sample> sampleList = singletonList(new Sample(statusMetricName, emptyList(), emptyList(),
+                                                               statusMetricValue, firstPacket.timestamp * 1000));
+            metricFamilySamples.add(new MetricFamilySamples(statusMetricName, Collector.Type.UNTYPED, "status of service", sampleList));
+        }));
+
+        return new PrometheusModel(metricFamilySamples);
+    }
+
+}
diff --git a/metrics-proxy/src/test/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandlerTest.java b/metrics-proxy/src/test/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandlerTest.java
new file mode 100644
index 00000000000..d0ce2837568
--- /dev/null
+++ b/metrics-proxy/src/test/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandlerTest.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.http.prometheus;
+
+import ai.vespa.metricsproxy.http.HttpHandlerTestBase;
+import ai.vespa.metricsproxy.service.DummyService;
+import com.yahoo.container.jdisc.RequestHandlerTestDriver;
+import org.json.JSONArray;
+import org.json.JSONObject;
+import org.junit.BeforeClass;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author gjoranv
+ */
+@SuppressWarnings("UnstableApiUsage")
+public class PrometheusHandlerTest extends HttpHandlerTestBase {
+
+    private static final String V1_URI = URI_BASE + PrometheusHandler.V1_PATH;
+    private static final String VALUES_URI = URI_BASE + PrometheusHandler.VALUES_PATH;
+
+    private static String valuesResponse;
+
+    @BeforeClass
+    public static void setup() {
+        PrometheusHandler handler = new PrometheusHandler(Executors.newSingleThreadExecutor(),
+                                                          getMetricsManager(),
+                                                          vespaServices,
+                                                          getMetricsConsumers());
+        testDriver = new RequestHandlerTestDriver(handler);
+        valuesResponse = testDriver.sendRequest(VALUES_URI).readAll();
+    }
+
+    @Test
+    public void v1_response_contains_values_uri() throws Exception {
+        String response = testDriver.sendRequest(V1_URI).readAll();
+        JSONObject root = new JSONObject(response);
+        assertTrue(root.has("resources"));
+
+        JSONArray resources = root.getJSONArray("resources");
+        assertEquals(1, resources.length());
+
+        JSONObject valuesUrl = resources.getJSONObject(0);
+        assertEquals(VALUES_URI, valuesUrl.getString("url"));
+    }
+
+    @Ignore
+    @Test
+    public void visually_inspect_values_response() {
+        System.out.println(valuesResponse);
+    }
+
+    @Test
+    public void response_contains_node_status() {
+        assertTrue(valuesResponse.contains("vespa_node_status 1.0"));
+    }
+
+    @Test
+    public void response_contains_node_metrics() {
+        String cpu = getLine(valuesResponse, CPU_METRIC + "{");
+        assertTrue(cpu.contains("} 12.345"));   // metric value
+        assertTrue(cpu.contains("{vespaVersion="));
+    }
+
+    @Test
+    public void response_contains_service_status() {
+        assertTrue(valuesResponse.contains("vespa_dummy_status 1.0"));
+        assertTrue(valuesResponse.contains("vespa_down_service_status 0.0"));
+    }
+
+    @Test
+    public void response_contains_service_metrics() {
+        String dummy0 = getLine(valuesResponse, DummyService.NAME + "0");
+        assertTrue(dummy0.contains("c_test"));  // metric name
+        assertTrue(dummy0.contains("} 1.0"));   // metric value
+        assertTrue(dummy0.contains("consumer_dim=\"default-val\""));
+    }
+
+    // Find the first line that contains the given string
+    private String getLine(String raw, String searchString) {
+        for (var s : raw.split("\\n")) {
+            if (s.contains(searchString))
+                return s;
+        }
+        throw new IllegalArgumentException("No line containing string: " + searchString);
+    }
+}
diff --git a/metrics-proxy/src/test/java/ai/vespa/metricsproxy/service/DummyService.java b/metrics-proxy/src/test/java/ai/vespa/metricsproxy/service/DummyService.java
index 380a992aead..cf559628490 100644
--- a/metrics-proxy/src/test/java/ai/vespa/metricsproxy/service/DummyService.java
+++ b/metrics-proxy/src/test/java/ai/vespa/metricsproxy/service/DummyService.java
@@ -11,7 +11,7 @@ import ai.vespa.metricsproxy.metric.Metrics;
  * @author Unknown
  */
 public class DummyService extends VespaService {
-    static final String NAME = "dummy";
+    public static final String NAME = "dummy";
     public static final String METRIC_1 = "c.test";
     public static final String METRIC_2 = "val";
 
diff --git a/parent/pom.xml b/parent/pom.xml
index a81f64d1725..1b22bcefb18 100644
--- a/parent/pom.xml
+++ b/parent/pom.xml
@@ -436,6 +436,16 @@
                 <version>0.7</version>
             </dependency>
             <dependency>
+                <groupId>io.prometheus</groupId>
+                <artifactId>simpleclient</artifactId>
+                <version>${prometheus.client.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>io.prometheus</groupId>
+                <artifactId>simpleclient_common</artifactId>
+                <version>${prometheus.client.version}</version>
+            </dependency>
+            <dependency>
                 <groupId>org.ow2.asm</groupId>
                 <artifactId>asm</artifactId>
                 <version>${asm.version}</version>
@@ -777,6 +787,7 @@
         <doclint>all</doclint>
         <surefire.version>2.22.0</surefire.version>
         <junit.version>5.4.2</junit.version>
+        <prometheus.client.version>0.6.0</prometheus.client.version>
         <protobuf.version>3.7.0</protobuf.version>
     </properties>