Add support for exposing ECS task metadata as Spring properties

pom.xml

@@ -58,6 +58,7 @@
 		<module>spring-cloud-aws-starters/spring-cloud-aws-starter-integration-sns</module>
 		<module>spring-cloud-aws-starters/spring-cloud-aws-starter-sqs</module>
 		<module>spring-cloud-aws-starters/spring-cloud-aws-starter-integration-sqs</module>
+		<module>spring-cloud-aws-starters/spring-cloud-aws-starter-ecs</module>
 		<module>spring-cloud-aws-samples</module>
 		<module>spring-cloud-aws-test</module>
 		<module>spring-cloud-aws-modulith</module>

spring-cloud-aws-autoconfigure/src/main/java/io/awspring/cloud/autoconfigure/ecs/EcsTaskMetadataAutoConfiguration.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2013-2022 the original author or 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.awspring.cloud.autoconfigure.ecs;
+
+import org.springframework.boot.autoconfigure.AutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.annotation.Bean;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.web.client.RestClient;
+
+/**
+ * Configuration for exposing ECS task metadata as properties in the Spring application context.
+ *
+ * @author Jukka Palomäki
+ * @since 3.5.0
+ */
+@AutoConfiguration
+@ConditionalOnProperty(name = "spring.cloud.aws.ecs-task-metadata.enabled", havingValue = "true", matchIfMissing = false)
+@ConditionalOnExpression("environment['ECS_CONTAINER_METADATA_URI_V4'] != null and environment['ECS_CONTAINER_METADATA_URI_V4'].trim() != ''")
+public class EcsTaskMetadataAutoConfiguration {
+
+	@Bean
+	@ConditionalOnMissingBean
+	public EcsTaskMetadataPropertySource ecsTaskMetadataPropertySource(ConfigurableEnvironment env,
+			EcsTaskMetadataResolver ecsTaskMetadataResolver) {
+		EcsTaskMetadataPropertySource propertySource = new EcsTaskMetadataPropertySource("EcsTaskMetadata",
+				ecsTaskMetadataResolver);
+		propertySource.init();
+		env.getPropertySources().addFirst(propertySource);
+		return propertySource;
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public EcsTaskMetadataResolver ecsTaskMetadataResolver(RestClient.Builder restClientBuilder) {
+		return new EcsTaskMetadataResolver(restClientBuilder);
+	}
+}

spring-cloud-aws-autoconfigure/src/main/java/io/awspring/cloud/autoconfigure/ecs/EcsTaskMetadataPropertySource.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2013-2022 the original author or 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.awspring.cloud.autoconfigure.ecs;
+
+import io.awspring.cloud.core.config.AwsPropertySource;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import org.springframework.lang.Nullable;
+
+/**
+ * Exposes ECS task metadata as Spring properties.
+ *
+ * @author Jukka Palomäki
+ * @since 3.5.0
+ */
+public class EcsTaskMetadataPropertySource
+		extends AwsPropertySource<EcsTaskMetadataPropertySource, EcsTaskMetadataResolver> {
+
+	private final String context;
+
+	private final EcsTaskMetadataResolver ecsTaskMetadataResolver;
+
+	private final Map<String, String> properties = new LinkedHashMap<>();
+
+	public EcsTaskMetadataPropertySource(String context, EcsTaskMetadataResolver ecsTaskMetadataResolver) {
+		super(context, ecsTaskMetadataResolver);
+		this.context = context;
+		this.ecsTaskMetadataResolver = ecsTaskMetadataResolver;
+	}
+
+	@Override
+	public EcsTaskMetadataPropertySource copy() {
+		return new EcsTaskMetadataPropertySource(context, source);
+	}
+
+	@Override
+	public void init() {
+		properties.putAll(ecsTaskMetadataResolver.getEcsTaskMetadata());
+	}
+
+	@Override
+	public String[] getPropertyNames() {
+		return properties.keySet().toArray(String[]::new);
+	}
+
+	@Override
+	@Nullable
+	public Object getProperty(String name) {
+		return properties.get(name);
+	}
+}

spring-cloud-aws-autoconfigure/src/main/java/io/awspring/cloud/autoconfigure/ecs/EcsTaskMetadataResolver.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2013-2022 the original author or 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.awspring.cloud.autoconfigure.ecs;
+
+import java.util.*;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.MediaType;
+import org.springframework.web.client.RestClient;
+import org.springframework.web.client.RestClient.Builder;
+import org.springframework.web.client.RestClientException;
+
+/**
+ * Resolves ECS task metadata. Supports ECS task metadata endpoint version 4.
+ * <p>
+ * See <a href="https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-metadata-endpoint-v4.html">AWS
+ * documentation</a> for more details.
+ *
+ * @author Jukka Palomäki
+ * @since 3.5.0
+ */
+public class EcsTaskMetadataResolver {
+
+	private static final Logger LOGGER = LoggerFactory.getLogger(EcsTaskMetadataResolver.class);
+	private static final String ECS_CONTAINER_METADATA_URI_V4 = System.getenv("ECS_CONTAINER_METADATA_URI_V4");
+
+	/** We expose a subset of available task metadata */
+	private static final Set<String> EXPOSED_PROPERTIES = Set.of("Cluster", "ServiceName", "TaskARN", "Family",
+			"Revision", "AvailabilityZone", "LaunchType");
+
+	private final RestClient restClient;
+
+	public EcsTaskMetadataResolver(Builder restClientBuilder) {
+		this.restClient = restClientBuilder.baseUrl(ECS_CONTAINER_METADATA_URI_V4).build();
+	}
+
+	/**
+	 * Returns ECS task metadata. If unable to fetch the metadata, an empty Map is returned.
+	 */
+	public Map<String, String> getEcsTaskMetadata() {
+		Map<String, String> properties = new LinkedHashMap<>();
+		tryPopulateTaskMetadata(properties);
+		return properties;
+	}
+
+	@SuppressWarnings("unchecked")
+	private void tryPopulateTaskMetadata(Map<String, String> properties) {
+		try {
+			LOGGER.debug("Getting ECS task metadata from {}/task", ECS_CONTAINER_METADATA_URI_V4);
+			Map<String, Object> taskMetadata = restClient.get().uri("/task").accept(MediaType.APPLICATION_JSON)
+					.retrieve().body(Map.class);
+			if (taskMetadata != null) {
+				for (String key : EXPOSED_PROPERTIES) {
+					if (taskMetadata.containsKey(key)) {
+						properties.put("ecs-task-metadata." + key, taskMetadata.get(key).toString());
+					}
+				}
+			}
+		} catch (IllegalArgumentException | RestClientException e) {
+			LOGGER.error("Error getting ECS task metadata", e);
+		}
+	}
+}

spring-cloud-aws-autoconfigure/src/main/java/io/awspring/cloud/autoconfigure/ecs/package-info.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2013-2022 the original author or 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.
+ */
+
+/**
+ * Auto-configuration for ECS (Elastic Container Service) integration.
+ */
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package io.awspring.cloud.autoconfigure.ecs;

spring-cloud-aws-autoconfigure/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -15,3 +15,4 @@ io.awspring.cloud.autoconfigure.config.secretsmanager.SecretsManagerAutoConfigur
 io.awspring.cloud.autoconfigure.config.parameterstore.ParameterStoreReloadAutoConfiguration
 io.awspring.cloud.autoconfigure.config.parameterstore.ParameterStoreAutoConfiguration
 io.awspring.cloud.autoconfigure.config.s3.S3ReloadAutoConfiguration
+io.awspring.cloud.autoconfigure.ecs.EcsTaskMetadataAutoConfiguration

spring-cloud-aws-starters/spring-cloud-aws-starter-ecs/pom.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+		 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>spring-cloud-aws</artifactId>
+		<groupId>io.awspring.cloud</groupId>
+		<version>4.0.0-SNAPSHOT</version>
+		<relativePath>../../pom.xml</relativePath>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+
+	<name>Spring Cloud ECS Starter</name>
+	<artifactId>spring-cloud-aws-starter-ecs</artifactId>
+
+	<dependencies>
+		<dependency>
+			<groupId>io.awspring.cloud</groupId>
+			<artifactId>spring-cloud-aws-starter</artifactId>
+		</dependency>
+	</dependencies>
+
+</project>