feat: Add readTimeout and conenctionTimeout as configurable parameters (#1658)

I got the issue like below so I would like to contribute to fix it by
apply configurable for `connectionTimeout` and `readTimeout`.
```
stack_trace: java.io.IOException: ailed to push metrics to the Prometheus Pushgateway on <pushgateway_address>: Read timed out
Caused by: java.net.SocketTimeoutException: Read timed out
```
- AS-IS: the current connectionTimeout and readTimeout is 10s
- TOBE: we can create builder with connectionTimeout and readTimeout
custom value, default value is 10s

---------

Signed-off-by: huan.huynh <[email protected]>
Signed-off-by: Gregor Zeitlinger <[email protected]>
Co-authored-by: Gregor Zeitlinger <[email protected]>

Author: hmhuan

prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/ExporterPushgatewayProperties.java

@@ -1,5 +1,6 @@
 package io.prometheus.metrics.config;
 
+import java.time.Duration;
 import java.util.Map;
 import javax.annotation.Nullable;
 
@@ -9,21 +10,29 @@ public class ExporterPushgatewayProperties {
   private static final String JOB = "job";
   private static final String SCHEME = "scheme";
   private static final String ESCAPING_SCHEME = "escapingScheme";
+  private static final String READ_TIMEOUT = "readTimeoutSeconds";
+  private static final String CONNECT_TIMEOUT = "connectTimeoutSeconds";
   private static final String PREFIX = "io.prometheus.exporter.pushgateway";
   @Nullable private final String scheme;
   @Nullable private final String address;
   @Nullable private final String job;
   @Nullable private final EscapingScheme escapingScheme;
+  @Nullable private final Duration connectTimeout;
+  @Nullable private final Duration readTimeout;
 
   private ExporterPushgatewayProperties(
       @Nullable String address,
       @Nullable String job,
       @Nullable String scheme,
-      @Nullable EscapingScheme escapingScheme) {
+      @Nullable EscapingScheme escapingScheme,
+      @Nullable Duration connectTimeout,
+      @Nullable Duration readTimeout) {
     this.address = address;
     this.job = job;
     this.scheme = scheme;
     this.escapingScheme = escapingScheme;
+    this.connectTimeout = connectTimeout;
+    this.readTimeout = readTimeout;
   }
 
   /** Address of the Pushgateway in the form {@code host:port}. Default is {@code localhost:9091} */
@@ -56,6 +65,18 @@ public EscapingScheme getEscapingScheme() {
     return escapingScheme;
   }
 
+  /** Connection timeout for connections to the Pushgateway. */
+  @Nullable
+  public Duration getConnectTimeout() {
+    return connectTimeout;
+  }
+
+  /** Read timeout for connections to the Pushgateway. */
+  @Nullable
+  public Duration getReadTimeout() {
+    return readTimeout;
+  }
+
   /**
    * Note that this will remove entries from {@code properties}. This is because we want to know if
    * there are unused properties remaining after all properties have been loaded.
@@ -66,6 +87,8 @@ static ExporterPushgatewayProperties load(Map<Object, Object> properties)
     String job = Util.loadString(PREFIX + "." + JOB, properties);
     String scheme = Util.loadString(PREFIX + "." + SCHEME, properties);
     String escapingScheme = Util.loadString(PREFIX + "." + ESCAPING_SCHEME, properties);
+    Duration connectTimeout = Util.loadOptionalDuration(PREFIX + "." + CONNECT_TIMEOUT, properties);
+    Duration readTimeout = Util.loadOptionalDuration(PREFIX + "." + READ_TIMEOUT, properties);
 
     if (scheme != null) {
       if (!scheme.equals("http") && !scheme.equals("https")) {
@@ -77,7 +100,7 @@ static ExporterPushgatewayProperties load(Map<Object, Object> properties)
     }
 
     return new ExporterPushgatewayProperties(
-        address, job, scheme, parseEscapingScheme(escapingScheme));
+        address, job, scheme, parseEscapingScheme(escapingScheme), connectTimeout, readTimeout);
   }
 
   private static @Nullable EscapingScheme parseEscapingScheme(@Nullable String scheme) {
@@ -111,6 +134,8 @@ public static class Builder {
     @Nullable private String job;
     @Nullable private String scheme;
     @Nullable private EscapingScheme escapingScheme;
+    @Nullable private Duration connectTimeout;
+    @Nullable private Duration readTimeout;
 
     private Builder() {}
 
@@ -134,8 +159,19 @@ public Builder escapingScheme(EscapingScheme escapingScheme) {
       return this;
     }
 
+    public Builder connectTimeout(Duration connectTimeout) {
+      this.connectTimeout = connectTimeout;
+      return this;
+    }
+
+    public Builder readTimeout(Duration readTimeout) {
+      this.readTimeout = readTimeout;
+      return this;
+    }
+
     public ExporterPushgatewayProperties build() {
-      return new ExporterPushgatewayProperties(address, job, scheme, escapingScheme);
+      return new ExporterPushgatewayProperties(
+          address, job, scheme, escapingScheme, connectTimeout, readTimeout);
     }
   }
 }

prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/Util.java

@@ -1,5 +1,6 @@
 package io.prometheus.metrics.config;
 
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -160,14 +161,30 @@ static Long loadLong(String name, Map<Object, Object> properties)
     return null;
   }
 
+  @Nullable
+  static Duration loadOptionalDuration(String name, Map<Object, Object> properties)
+      throws PrometheusPropertiesException {
+
+    Long value = loadLong(name, properties);
+
+    assertValue(value, t -> t >= 0, "Expecting value >= 0.", null, name);
+
+    if (value == null || value == 0) {
+      return null;
+    }
+    return Duration.ofSeconds(value);
+  }
+
   static <T extends Number> void assertValue(
-      @Nullable T number, Predicate<T> predicate, String message, String prefix, String name)
+      @Nullable T number,
+      Predicate<T> predicate,
+      String message,
+      @Nullable String prefix,
+      String name)
       throws PrometheusPropertiesException {
     if (number != null && !predicate.test(number)) {
-      String fullMessage =
-          prefix == null
-              ? name + ": " + message
-              : String.format("%s.%s: %s Found: %s", prefix, name, message, number);
+      String fullKey = prefix == null ? name : prefix + "." + name;
+      String fullMessage = String.format("%s: %s Found: %s", fullKey, message, number);
       throw new PrometheusPropertiesException(fullMessage);
     }
   }

prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPushgatewayPropertiesTest.java

@@ -3,6 +3,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
+import java.time.Duration;
 import java.util.HashMap;
 import java.util.Map;
 import org.junit.jupiter.api.Test;
@@ -41,11 +42,15 @@ void builder() {
             .job("job")
             .scheme("http")
             .escapingScheme(EscapingScheme.DOTS_ESCAPING)
+            .connectTimeout(Duration.ofSeconds(1))
+            .readTimeout(Duration.ofSeconds(2))
             .build();
 
     assertThat(properties.getAddress()).isEqualTo("http://localhost");
     assertThat(properties.getJob()).isEqualTo("job");
     assertThat(properties.getScheme()).isEqualTo("http");
     assertThat(properties.getEscapingScheme()).isEqualTo(EscapingScheme.DOTS_ESCAPING);
+    assertThat(properties.getConnectTimeout()).isEqualTo(Duration.ofSeconds(1));
+    assertThat(properties.getReadTimeout()).isEqualTo(Duration.ofSeconds(2));
   }
 }

prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/UtilTest.java

@@ -0,0 +1,50 @@
+package io.prometheus.metrics.config;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+import java.time.Duration;
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+
+class UtilTest {
+  @Test
+  void loadOptionalDuration_positive() {
+    Map<Object, Object> properties = new HashMap<>(Map.of("foo", "5"));
+
+    assertThat(Util.loadOptionalDuration("foo", properties)).isEqualTo(Duration.ofSeconds(5));
+  }
+
+  @Test
+  void loadOptionalDuration_zero() {
+    Map<Object, Object> properties = new HashMap<>(Map.of("foo", "0"));
+
+    assertThat(Util.loadOptionalDuration("foo", properties)).isNull();
+  }
+
+  @Test
+  void loadOptionalDuration_missing() {
+    Map<Object, Object> properties = new HashMap<>();
+
+    assertThat(Util.loadOptionalDuration("foo", properties)).isNull();
+  }
+
+  @Test
+  void loadOptionalDuration_negative_throws() {
+    Map<Object, Object> properties = new HashMap<>(Map.of("foo", "-1"));
+
+    assertThatExceptionOfType(PrometheusPropertiesException.class)
+        .isThrownBy(() -> Util.loadOptionalDuration("foo", properties))
+        .withMessage("foo: Expecting value >= 0. Found: -1");
+  }
+
+  @Test
+  void loadOptionalDuration_invalidNumber_throws() {
+    Map<Object, Object> properties = new HashMap<>(Map.of("foo", "abc"));
+
+    assertThatExceptionOfType(PrometheusPropertiesException.class)
+        .isThrownBy(() -> Util.loadOptionalDuration("foo", properties))
+        .withMessage("foo=abc: Expecting long value");
+  }
+}

prometheus-metrics-exporter-pushgateway/src/main/java/io/prometheus/metrics/exporter/pushgateway/PushGateway.java

@@ -27,6 +27,7 @@
 import java.net.URLEncoder;
 import java.net.UnknownHostException;
 import java.nio.charset.StandardCharsets;
+import java.time.Duration;
 import java.util.Base64;
 import java.util.Collections;
 import java.util.HashMap;
@@ -79,16 +80,15 @@
  * href="https://github.com/prometheus/pushgateway">https://github.com/prometheus/pushgateway</a>.
  */
 public class PushGateway {
-
-  private static final int MILLISECONDS_PER_SECOND = 1000;
-
   private final URL url;
   private final ExpositionFormatWriter writer;
   private final boolean prometheusTimestampsInMs;
   private final Map<String, String> requestHeaders;
   private final PrometheusRegistry registry;
   private final HttpConnectionFactory connectionFactory;
   private final EscapingScheme escapingScheme;
+  private final Duration connectionTimeout;
+  private final Duration readTimeout;
 
   private PushGateway(
       PrometheusRegistry registry,
@@ -97,13 +97,17 @@ private PushGateway(
       HttpConnectionFactory connectionFactory,
       Map<String, String> requestHeaders,
       boolean prometheusTimestampsInMs,
-      EscapingScheme escapingScheme) {
+      EscapingScheme escapingScheme,
+      Duration connectionTimeout,
+      Duration readTimeout) {
     this.registry = registry;
     this.url = url;
     this.requestHeaders = Collections.unmodifiableMap(new HashMap<>(requestHeaders));
     this.connectionFactory = connectionFactory;
     this.prometheusTimestampsInMs = prometheusTimestampsInMs;
     this.escapingScheme = escapingScheme;
+    this.connectionTimeout = connectionTimeout;
+    this.readTimeout = readTimeout;
     writer = getWriter(format);
     if (!writer.isAvailable()) {
       throw new RuntimeException(writer.getClass() + " is not available");
@@ -206,8 +210,8 @@ private void doRequest(@Nullable PrometheusRegistry registry, String method) thr
       }
       connection.setRequestMethod(method);
 
-      connection.setConnectTimeout(10 * MILLISECONDS_PER_SECOND);
-      connection.setReadTimeout(10 * MILLISECONDS_PER_SECOND);
+      connection.setConnectTimeout((int) this.connectionTimeout.toMillis());
+      connection.setReadTimeout((int) this.readTimeout.toMillis());
       connection.connect();
 
       try {
@@ -277,6 +281,8 @@ public static class Builder {
     @Nullable private String address;
     @Nullable private Scheme scheme;
     @Nullable private String job;
+    @Nullable private Duration connectionTimeout;
+    @Nullable private Duration readTimeout;
     private boolean prometheusTimestampsInMs;
     private final Map<String, String> requestHeaders = new HashMap<>();
     private PrometheusRegistry registry = PrometheusRegistry.defaultRegistry;
@@ -395,6 +401,49 @@ public Builder prometheusTimestampsInMs(boolean prometheusTimestampsInMs) {
       return this;
     }
 
+    /**
+     * Specify the connection timeout for HTTP connections to the PushGateway. Default is 10
+     * seconds.
+     *
+     * @param connectionTimeout timeout value
+     * @return this {@link Builder} instance
+     */
+    public Builder connectionTimeout(Duration connectionTimeout) {
+      this.connectionTimeout = connectionTimeout;
+      return this;
+    }
+
+    private Duration getConnectionTimeout(@Nullable ExporterPushgatewayProperties properties) {
+      if (properties != null && properties.getConnectTimeout() != null) {
+        return properties.getConnectTimeout();
+      } else if (this.connectionTimeout != null) {
+        return this.connectionTimeout;
+      } else {
+        return Duration.ofSeconds(10);
+      }
+    }
+
+    /**
+     * Specify the read timeout for HTTP connections to the PushGateway. Default is 10 seconds.
+     *
+     * @param readTimeout timeout value
+     * @return this {@link Builder} instance
+     */
+    public Builder readTimeout(Duration readTimeout) {
+      this.readTimeout = readTimeout;
+      return this;
+    }
+
+    private Duration getReadTimeout(@Nullable ExporterPushgatewayProperties properties) {
+      if (properties != null && properties.getReadTimeout() != null) {
+        return properties.getReadTimeout();
+      } else if (this.readTimeout != null) {
+        return this.readTimeout;
+      } else {
+        return Duration.ofSeconds(10);
+      }
+    }
+
     private boolean getPrometheusTimestampsInMs() {
       // accept either to opt in to timestamps in milliseconds
       return config.getExporterProperties().getPrometheusTimestampsInMs()
@@ -496,7 +545,9 @@ public PushGateway build() {
             connectionFactory,
             requestHeaders,
             getPrometheusTimestampsInMs(),
-            getEscapingScheme(properties));
+            getEscapingScheme(properties),
+            getConnectionTimeout(properties),
+            getReadTimeout(properties));
       } catch (MalformedURLException e) {
         throw new PrometheusPropertiesException(
             address + ": Invalid address. Expecting <host>:<port>");