Adds new module for Prometheus PushGateway (#848)

PR adds support for  Prometheus PushGateway. Once module is included in classpath, it will be enabled by default.

Added:

- new module
- docs for new module
- tests for new module

gradle/libs.versions.toml

@@ -11,6 +11,7 @@ managed-metrics-core = '4.2.28'
 managed-micrometer = '1.13.4'
 managed-micrometer-tracing = '1.3.4'
 managed-new-relic-registry = '0.10.0'
+managed-prometheus-metrics-exporter-pushgateway = '1.3.1'
 reflections = '0.10.2'
 
 jcache = "1.1.1"
@@ -47,6 +48,8 @@ boms-micrometer = { module = 'io.micrometer:micrometer-bom', version.ref = 'mana
 grpc-api = { module = 'io.grpc:grpc-api' }
 hdr-histogram = { module = 'org.hdrhistogram:HdrHistogram', version.ref = 'hdr-histogram' }
 
+managed-prometheus-metrics-exporter-pushgateway = { module = 'io.prometheus:prometheus-metrics-exporter-pushgateway', version.ref = 'managed-prometheus-metrics-exporter-pushgateway' }
+
 managed-metrics-core = { module = 'io.dropwizard.metrics:metrics-core', version.ref = 'managed-metrics-core' }
 managed-micrometer-registry-new-relic-telemetry = { module = 'com.newrelic.telemetry:micrometer-registry-new-relic', version.ref = 'managed-new-relic-registry' }
 managed-micrometer-core = { module = 'io.micrometer:micrometer-core', version.ref = 'managed-micrometer' }

micrometer-registry-prometheus-pushgateway/build.gradle

@@ -0,0 +1,16 @@
+plugins {
+    id 'io.micronaut.build.internal.micrometer-registry'
+}
+
+dependencies {
+    api libs.micrometer.registry.prometheus
+    api projects.micronautMicrometerRegistryPrometheus
+    api libs.managed.prometheus.metrics.exporter.pushgateway
+    testImplementation(mnSerde.micronaut.serde.jackson)
+}
+
+micronautBuild {
+    binaryCompatibility {
+        enabledAfter '5.9.0' // adjust as needed
+    }
+}

micrometer-registry-prometheus-pushgateway/src/main/java/io/micronaut/configuration/metrics/micrometer/prometheus/pushgateway/PrometheusPushGatewayConfig.java

@@ -0,0 +1,140 @@
+/*
+ * Copyright 2017-2024 original authors
+ *
+ * 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
+ *
+ * https://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 io.micronaut.configuration.metrics.micrometer.prometheus.pushgateway;
+
+import io.micronaut.configuration.metrics.micrometer.prometheus.PrometheusMeterRegistryFactory;
+import io.micronaut.context.annotation.BootstrapContextCompatible;
+import io.micronaut.context.annotation.ConfigurationBuilder;
+import io.micronaut.context.annotation.ConfigurationProperties;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.annotation.Internal;
+import io.micronaut.core.annotation.Nullable;
+import io.micronaut.core.util.StringUtils;
+import io.prometheus.metrics.exporter.pushgateway.PushGateway;
+
+import java.time.Duration;
+import java.util.Map;
+
+/**
+ * Configuration for the {@link PushGateway}.
+ */
+@ConfigurationProperties(PrometheusPushGatewayFactory.PROMETHEUS_PUSHGATEWAY_CONFIG)
+@BootstrapContextCompatible
+@Requires(property = PrometheusPushGatewayFactory.PROMETHEUS_PUSHGATEWAY_ENABLED, value = StringUtils.TRUE, defaultValue = StringUtils.TRUE)
+@Requires(property = PrometheusMeterRegistryFactory.PROMETHEUS_ENABLED, value = StringUtils.TRUE, defaultValue = StringUtils.TRUE)
+@Internal
+final class PrometheusPushGatewayConfig {
+
+    @ConfigurationBuilder(prefixes = "", excludes = {"basicAuth", "groupingKey"})
+    final PushGateway.Builder builder = PushGateway.builder();
+
+    private String basicAuthUsername;
+    private String basicAuthPassword;
+    private boolean enabled;
+    private Duration interval;
+    private Duration initialDelay;
+    private Map<String, String> groupingKeys;
+
+    /**
+     * @return Map of the grouping keys.
+     */
+    @Nullable
+    public Map<String, String> getGroupingKeys() {
+        return groupingKeys;
+    }
+
+    /**
+     * @param groupingKeys Map of the grouping keys.
+     */
+    public void setGroupingKeys(@Nullable Map<String, String> groupingKeys) {
+        this.groupingKeys = groupingKeys;
+    }
+
+    /**
+     * @return username for basic auth.
+     */
+    @Nullable
+    public String getBasicAuthUsername() {
+        return basicAuthUsername;
+    }
+
+    /**
+     * @param basicAuthUsername the username for basic auth.
+     */
+    public void setBasicAuthUsername(@Nullable String basicAuthUsername) {
+        this.basicAuthUsername = basicAuthUsername;
+    }
+
+    /**
+     * @return password for the basic auth.
+     */
+    @Nullable
+    public String getBasicAuthPassword() {
+        return basicAuthPassword;
+    }
+
+    /**
+     * @param basicAuthPassword the password for basic auth.
+     */
+    public void setBasicAuthPassword(@Nullable String basicAuthPassword) {
+        this.basicAuthPassword = basicAuthPassword;
+    }
+
+    /**
+     * @return interval of {@link PrometheusPushGatewayScheduler#pushData()}.
+     */
+    @Nullable
+    public Duration getInterval() {
+        return interval;
+    }
+
+    /**
+     * @param interval interval for {@link PrometheusPushGatewayScheduler#pushData()}.
+     */
+    public void setInterval(@Nullable Duration interval) {
+        this.interval = interval;
+    }
+
+    /**
+     * @return initialDelay of {@link PrometheusPushGatewayScheduler#pushData()}.
+     */
+    @Nullable
+    public Duration getInitialDelay() {
+        return initialDelay;
+    }
+
+    /**
+     * @param initialDelay interval for {@link PrometheusPushGatewayScheduler#pushData()}.
+     */
+    public void setInitialDelay(@Nullable Duration initialDelay) {
+        this.initialDelay = initialDelay;
+    }
+
+    /**
+     * @return is PushGateway feature enabled.
+     */
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    /**
+     * @param enabled is PushGateway feature enabled.
+     */
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+}

micrometer-registry-prometheus-pushgateway/src/main/java/io/micronaut/configuration/metrics/micrometer/prometheus/pushgateway/PrometheusPushGatewayFactory.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2017-2019 original authors
+ *
+ * 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
+ *
+ * https://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 io.micronaut.configuration.metrics.micrometer.prometheus.pushgateway;
+
+import io.micrometer.prometheusmetrics.PrometheusMeterRegistry;
+import io.micronaut.context.annotation.Factory;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.annotation.Internal;
+import io.micronaut.core.util.StringUtils;
+import io.prometheus.metrics.exporter.pushgateway.PushGateway;
+import jakarta.inject.Singleton;
+
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_EXPORT;
+
+/**
+ * Creates a Prometheus {@link PushGateway}.
+ */
+@Factory
+@Internal
+class PrometheusPushGatewayFactory {
+
+    public static final String PROMETHEUS_PUSHGATEWAY_CONFIG = MICRONAUT_METRICS_EXPORT + ".prometheus.pushgateway";
+    public static final String PROMETHEUS_PUSHGATEWAY_ENABLED = PROMETHEUS_PUSHGATEWAY_CONFIG + ".enabled";
+
+    /**
+     * Create a PushGateway bean if global metrics are enabled
+     * , Prometheus is enabled and PushGateway is enabled. Will be true by default when this
+     * configuration is included in project.
+     *
+     * @return PushGateway
+     */
+    @Singleton
+    @Requires(beans = PrometheusPushGatewayConfig.class)
+    @Requires(beans = PrometheusMeterRegistry.class)
+    PushGateway pushGateway(PrometheusMeterRegistry prometheusMeterRegistry, PrometheusPushGatewayConfig prometheusRegistryConfig) {
+        PushGateway.Builder builder =  prometheusRegistryConfig.builder.registry(prometheusMeterRegistry.getPrometheusRegistry());
+
+        if (!StringUtils.isEmpty(prometheusRegistryConfig.getBasicAuthUsername()) && !StringUtils.isEmpty(prometheusRegistryConfig.getBasicAuthPassword())) {
+            builder.basicAuth(prometheusRegistryConfig.getBasicAuthUsername(), prometheusRegistryConfig.getBasicAuthPassword());
+        }
+
+        if (prometheusRegistryConfig.getGroupingKeys() != null && !prometheusRegistryConfig.getGroupingKeys().isEmpty()) {
+            prometheusRegistryConfig.getGroupingKeys().forEach(builder::groupingKey);
+        }
+
+        return builder.build();
+    }
+
+}

micrometer-registry-prometheus-pushgateway/src/main/java/io/micronaut/configuration/metrics/micrometer/prometheus/pushgateway/PrometheusPushGatewayScheduler.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2017-2024 original authors
+ *
+ * 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
+ *
+ * https://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 io.micronaut.configuration.metrics.micrometer.prometheus.pushgateway;
+
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.annotation.Internal;
+import io.micronaut.scheduling.annotation.Scheduled;
+import io.prometheus.metrics.exporter.pushgateway.PushGateway;
+import jakarta.inject.Singleton;
+
+import java.io.IOException;
+
+/**
+ * PrometheusPushGatewayScheduler pushes data to Prometheus pushGateway.
+ */
+@Singleton
+@Requires(beans = PushGateway.class)
+@Internal
+final class PrometheusPushGatewayScheduler {
+
+    private final PushGateway pushGateway;
+
+    PrometheusPushGatewayScheduler(PushGateway pushGateway) {
+        this.pushGateway = pushGateway;
+    }
+
+    @Scheduled(
+        fixedDelay = "${micronaut.metrics.export.prometheus.pushgateway.interval:1m}",
+        initialDelay = "${micronaut.metrics.export.prometheus.pushgateway.initial-delay:1m}")
+    void pushData() throws IOException {
+        pushGateway.push();
+    }
+
+}

micrometer-registry-prometheus-pushgateway/src/main/java/io/micronaut/configuration/metrics/micrometer/prometheus/pushgateway/package-info.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2017-2019 original authors
+ *
+ * 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
+ *
+ * https://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.
+ */
+/**
+ * Micronaut integration with Prometheus PushGateway.
+ */
+@Configuration
+@Requires(property = PrometheusPushGatewayFactory.PROMETHEUS_PUSHGATEWAY_ENABLED, notEquals = StringUtils.FALSE)
+@Requires(property = PrometheusMeterRegistryFactory.PROMETHEUS_ENABLED, notEquals = StringUtils.FALSE)
+package io.micronaut.configuration.metrics.micrometer.prometheus.pushgateway;
+
+import io.micronaut.configuration.metrics.micrometer.prometheus.PrometheusMeterRegistryFactory;
+import io.micronaut.context.annotation.Configuration;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.util.StringUtils;

micrometer-registry-prometheus-pushgateway/src/test/groovy/io/micronaut/configuration/metrics/micrometer/prometheus/controllers/MetricsTestController.groovy

@@ -0,0 +1,27 @@
+package io.micronaut.configuration.metrics.micrometer.prometheus.controllers
+
+import io.micronaut.http.MediaType
+import io.micronaut.http.annotation.Body
+import io.micronaut.http.annotation.Consumes
+import io.micronaut.http.annotation.Controller
+import io.micronaut.http.annotation.Get
+import io.micronaut.http.annotation.Header
+import io.micronaut.http.annotation.Put
+
+@Controller("/metrics/job/test")
+class MetricsTestController {
+
+    private static String authHeader = ""
+
+    @Get
+    String hello() {
+        return authHeader
+    }
+
+    @Put
+    @Consumes(MediaType.TEXT_PLAIN)
+    String test(@Body String body, @Header("Authorization") auth) {
+        MetricsTestController.authHeader = auth
+        return "OK"
+    }
+}

micrometer-registry-prometheus-pushgateway/src/test/groovy/io/micronaut/configuration/metrics/micrometer/prometheus/pushgateway/PrometheusPushGatewayFactorySpec.groovy

@@ -0,0 +1,45 @@
+package io.micronaut.configuration.metrics.micrometer.prometheus.pushgateway
+
+import io.micrometer.core.instrument.MeterRegistry
+import io.micronaut.context.ApplicationContext
+import io.prometheus.metrics.exporter.pushgateway.PushGateway
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_ENABLED
+import static PrometheusPushGatewayFactory.PROMETHEUS_PUSHGATEWAY_ENABLED
+
+class PrometheusPushGatewayFactorySpec extends Specification {
+
+    void "verify PushGateway is created by default when this configuration used"() {
+        when:
+        ApplicationContext context = ApplicationContext.run()
+
+        then:
+        context.getBeansOfType(MeterRegistry).size() == 1
+        context.getBeansOfType(MeterRegistry)*.class*.simpleName.containsAll(['PrometheusMeterRegistry'])
+        context.getBeansOfType(PushGateway)
+
+        cleanup:
+        context.stop()
+    }
+
+    @Unroll
+    void "verify PrometheusMeterRegistry bean exists = #result when config #cfg = #setting"() {
+        when:
+        ApplicationContext context = ApplicationContext.run([(cfg): setting])
+
+        then:
+        context.findBean(PushGateway).isPresent() == result
+
+        cleanup:
+        context.stop()
+
+        where:
+        cfg                                   | setting | result
+        MICRONAUT_METRICS_ENABLED             | false   | false
+        MICRONAUT_METRICS_ENABLED             | true    | true
+        PROMETHEUS_PUSHGATEWAY_ENABLED        | true    | true
+        PROMETHEUS_PUSHGATEWAY_ENABLED        | false   | false
+    }
+}