Implement Asynchronous EC2 Metadata Client

core/imds/pom.xml

@@ -114,8 +114,8 @@
         </dependency>
         <dependency>
             <groupId>software.amazon.awssdk</groupId>
-            <artifactId>aws-crt-client</artifactId>
-            <version>${awsjavasdk.version}-PREVIEW</version>
+            <artifactId>netty-nio-client</artifactId>
+            <version>${awsjavasdk.version}</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

core/imds/src/main/java/software/amazon/awssdk/imds/Ec2MetadataAsyncClient.java

@@ -15,38 +15,33 @@
 
 package software.amazon.awssdk.imds;
 
-import java.net.URI;
-import java.time.Duration;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import software.amazon.awssdk.annotations.SdkPublicApi;
-import software.amazon.awssdk.core.internal.http.loader.DefaultSdkAsyncHttpClientBuilder;
-import software.amazon.awssdk.core.retry.RetryMode;
-import software.amazon.awssdk.core.retry.backoff.BackoffStrategy;
 import software.amazon.awssdk.http.async.SdkAsyncHttpClient;
 import software.amazon.awssdk.imds.internal.DefaultEc2MetadataAsyncClient;
-import software.amazon.awssdk.imds.internal.Ec2MetadataEndpointProvider;
 import software.amazon.awssdk.utils.SdkAutoCloseable;
 
 /**
- *  Interface to represent the Ec2Metadata Client Class. Used to access instance metadata from a running instance.
+ * Interface to represent the Ec2Metadata Client Class. Used to access instance metadata from a running instance.
  */
 @SdkPublicApi
 public interface Ec2MetadataAsyncClient extends SdkAutoCloseable {
 
     /**
      * Gets the specified instance metadata value by the given path.
-     * @param path  Input path
+     *
+     * @param path Input path
      * @return A CompletableFuture that completes when the MetadataResponse is made available.
      */
     CompletableFuture<MetadataResponse> get(String path);
 
     /**
-     * @return The Builder Object consisting all the fields.
+     * Create an {@link Ec2MetadataAsyncClient} instance using the default values.
+     *
+     * @return
      */
-    Ec2MetadataAsyncClient.Builder toBuilder();
-
     static Ec2MetadataAsyncClient create() {
         return builder().build();
     }
@@ -57,65 +52,30 @@ static Ec2MetadataAsyncClient.Builder builder() {
 
     /**
      * The builder definition for a {@link Ec2MetadataClient}. All parameters are optional and have default values if not
-     * specified. Therefore, an instance can be simply created with {@code Ec2MetadataAsyncClient.builder().build()} or {@code
-     * Ec2MetadataAsyncClient.create()}, both having the same result.
+     * specified. Therefore, an instance can be simply created with {@code Ec2MetadataAsyncClient.builder().build()} or
+     * {@code Ec2MetadataAsyncClient.create()}, both having the same result.
      */
-    interface Builder  {
-
-        /**
-         * Define the retry policy which includes the number of retry attempts for any failed request. If not specified, defaults
-         * to 3 retries using {@link BackoffStrategy#defaultStrategy(RetryMode)} with {@link RetryMode#STANDARD}.
-         *
-         * @param retryPolicy The retry policy which includes the number of retry attempts for any failed request.
-         * @return Returns a reference to this builder
-         */
-        Builder retryPolicy(Ec2MetadataRetryPolicy retryPolicy);
-
-        /**
-         * Define the endpoint of IMDS. If not specified, the endpoint is resolved using
-         * {@link Ec2MetadataEndpointProvider#resolveEndpoint(EndpointMode)}
-         *
-         * @param endpoint The endpoint of IMDS.
-         * @return Returns a reference to this builder
-         */
-        Builder endpoint(URI endpoint);
-
-        /**
-         * Define the Time to live (TTL) of the token. If not specified, defaults to 21,600 secs or 6 hours.
-         *
-         * @param tokenTtl The Time to live (TTL) of the token.
-         * @return Returns a reference to this builder
-         */
-        Builder tokenTtl(Duration tokenTtl);
-
-        /**
-         * Define the endpoint mode of IMDS. Supported values include IPv4 and IPv6. If not specified, the default value is
-         * resolved using {@link Ec2MetadataEndpointProvider#resolveEndpointMode()}
-         *
-         * @param endpointMode The endpoint mode of IMDS.Supported values include IPv4 and IPv6.
-         * @return Returns a reference to this builder
-         */
-        Builder endpointMode(EndpointMode endpointMode);
-
-        /**
-         * Define the {@link SdkAsyncHttpClient} instance to make the http requests. If not specified, the Client will try to
-         * instantiate a http client using {@link DefaultSdkAsyncHttpClientBuilder}.
-         *
-         * @param httpClient The SdkHttpClient instance to make the http requests.
-         * @return Returns a reference to this builder
-         */
-        Builder httpClient(SdkAsyncHttpClient httpClient);
+    interface Builder extends Ec2MetadataClientBuilder<Ec2MetadataAsyncClient.Builder, Ec2MetadataAsyncClient> {
 
         /**
          * Define the {@link ScheduledExecutorService} used to schedule asynchronous retry attempts. If not specified,
          * defaults to {@link Executors#newScheduledThreadPool} with a default value of 3 thread in the pool.
+         * If provided, the Ec2MetadataClient will <em>NOT</em> manage the lifetime if the httpClient and must therefore be
+         * closed explicitly by calling the {@link SdkAsyncHttpClient#close()} method on it.
          *
          * @param scheduledExecutorService the ScheduledExecutorService to use for retry attempt.
          * @return a reference to this builder
          */
         Builder scheduledExecutorService(ScheduledExecutorService scheduledExecutorService);
 
-        Ec2MetadataAsyncClient build();
-
+        /**
+         * Define the http client used by the Ec2 Metadata client. If provided, the Ec2MetadataClient will <em>NOT</em> manage the
+         * lifetime if the httpClient and must therefore be closed explicitly by calling the {@link SdkAsyncHttpClient#close()}
+         * method on it.
+         *
+         * @param httpClient the http client
+         * @return a reference to this builder
+         */
+        Builder httpClient(SdkAsyncHttpClient httpClient);
     }
 }

core/imds/src/main/java/software/amazon/awssdk/imds/Ec2MetadataClient.java

@@ -15,10 +15,9 @@
 
 package software.amazon.awssdk.imds;
 
-import java.net.URI;
-import java.time.Duration;
 import software.amazon.awssdk.annotations.SdkPublicApi;
 import software.amazon.awssdk.http.SdkHttpClient;
+import software.amazon.awssdk.http.async.SdkAsyncHttpClient;
 import software.amazon.awssdk.imds.internal.DefaultEc2MetadataClient;
 import software.amazon.awssdk.utils.SdkAutoCloseable;
 
@@ -37,12 +36,7 @@ public interface Ec2MetadataClient extends SdkAutoCloseable {
     MetadataResponse get(String path);
 
     /**
-     * @return The Builder Object consisting all the fields.
-     */
-    Ec2MetadataClient.Builder toBuilder();
-
-    /**
-     * Create an {@code Ec2Metadata} using the default values.
+     * Create an {@link Ec2MetadataClient} instance using the default values.
      */
     static Ec2MetadataClient create() {
         return builder().build();
@@ -51,57 +45,23 @@ static Ec2MetadataClient create() {
     /**
      * Creates a default builder for {@link Ec2MetadataClient}.
      */
-    static Ec2MetadataClient.Builder builder() {
+    static Builder builder() {
         return DefaultEc2MetadataClient.builder();
     }
 
     /**
      * The builder definition for a {@link Ec2MetadataClient}.
      */
-    interface Builder  {
-
-        /**
-         * Define the retry policy which includes the number of retry attempts for any failed request.
-         *
-         * @param retryPolicy The retry policy which includes the number of retry attempts for any failed request.
-         * @return Returns a reference to this builder
-         */
-        Builder retryPolicy(Ec2MetadataRetryPolicy retryPolicy);
-
-        /**
-         * Define the endpoint of IMDS.
-         *
-         * @param endpoint The endpoint of IMDS.
-         * @return Returns a reference to this builder
-         */
-        Builder endpoint(URI endpoint);
+    interface Builder extends Ec2MetadataClientBuilder<Ec2MetadataClient.Builder, Ec2MetadataClient> {
 
         /**
-         * Define the Time to live (TTL) of the token.
-         *
-         * @param tokenTtl The Time to live (TTL) of the token.
-         * @return Returns a reference to this builder
-         */
-        Builder tokenTtl(Duration tokenTtl);
-
-        /**
-         * Define the endpoint mode of IMDS. Supported values include IPv4 and IPv6.
-         *
-         * @param endpointMode The endpoint mode of IMDS.Supported values include IPv4 and IPv6.
-         * @return Returns a reference to this builder
-         */
-        Builder endpointMode(EndpointMode endpointMode);
-
-        /**
-         * Define the SdkHttpClient instance to make the http requests.
-         *
-         * @param httpClient The SdkHttpClient instance to make the http requests.
-         * @return Returns a reference to this builder
+         * Define the http client used by the Ec2 Metadata client. If provided, the Ec2MetadataClient will <em>NOT</em> manage the
+         * lifetime if the httpClient and must therefore be closed explicitly by calling the {@link SdkAsyncHttpClient#close()}
+         * method on it.
+         * @param httpClient the http client
+         * @return a reference to this builder
          */
         Builder httpClient(SdkHttpClient httpClient);
-
-        Ec2MetadataClient build();
-
     }
 
 }

core/imds/src/main/java/software/amazon/awssdk/imds/Ec2MetadataClientBuilder.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.imds;
+
+import java.net.URI;
+import java.time.Duration;
+import software.amazon.awssdk.annotations.SdkPublicApi;
+import software.amazon.awssdk.utils.builder.SdkBuilder;
+
+/**
+ * Base shared builder interface for Ec2MetadataClient
+ * @param <B> the Builder Type
+ * @param <T> the Ec2MetadataClient Type
+ */
+@SdkPublicApi
+public interface Ec2MetadataClientBuilder<B, T> extends SdkBuilder<Ec2MetadataClientBuilder<B, T>, T> {
+    /**
+     * Define the retry policy which includes the number of retry attempts for any failed request.
+     *
+     * @param retryPolicy The retry policy which includes the number of retry attempts for any failed request.
+     * @return a reference to this builder
+     */
+    B retryPolicy(Ec2MetadataRetryPolicy retryPolicy);
+
+    Ec2MetadataRetryPolicy getRetryPolicy();
+
+    /**
+     * Define the endpoint of IMDS.
+     *
+     * @param endpoint The endpoint of IMDS.
+     * @return a reference to this builder
+     */
+    B endpoint(URI endpoint);
+
+    URI getEndpoint();
+
+    /**
+     * Define the Time to live (TTL) of the token.
+     *
+     * @param tokenTtl The Time to live (TTL) of the token.
+     * @return a reference to this builder
+     */
+    B tokenTtl(Duration tokenTtl);
+
+    Duration getTokenTtl();
+
+    /**
+     * Define the endpoint mode of IMDS. Supported values include IPv4 and IPv6.
+     *
+     * @param endpointMode The endpoint mode of IMDS. Supported values include IPv4 and IPv6.
+     * @return a reference to this builder
+     */
+    B endpointMode(EndpointMode endpointMode);
+
+    EndpointMode getEndpointMode();
+
+}

core/imds/src/main/java/software/amazon/awssdk/imds/internal/BaseEc2MetadataClient.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.imds.internal;
+
+import static software.amazon.awssdk.imds.internal.Ec2MetadataEndpointProvider.DEFAULT_ENDPOINT_PROVIDER;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.net.URI;
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import software.amazon.awssdk.annotations.SdkInternalApi;
+import software.amazon.awssdk.http.AbortableInputStream;
+import software.amazon.awssdk.imds.Ec2MetadataClientBuilder;
+import software.amazon.awssdk.imds.Ec2MetadataRetryPolicy;
+import software.amazon.awssdk.imds.EndpointMode;
+import software.amazon.awssdk.utils.IoUtils;
+import software.amazon.awssdk.utils.Logger;
+import software.amazon.awssdk.utils.Validate;
+
+@SdkInternalApi
+public abstract class BaseEc2MetadataClient {
+
+    protected static final Duration DEFAULT_TOKEN_TTL = Duration.of(21_600, ChronoUnit.SECONDS);
+    private static final Logger log = Logger.loggerFor(BaseEc2MetadataClient.class);
+
+    protected final Ec2MetadataRetryPolicy retryPolicy;
+    protected final URI endpoint;
+    protected final RequestMarshaller requestMarshaller;
+    protected final Duration tokenTtl;
+
+    protected BaseEc2MetadataClient(Ec2MetadataClientBuilder<?, ?> builder) {
+        this.retryPolicy = Validate.getOrDefault(builder.getRetryPolicy(), Ec2MetadataRetryPolicy.builder()::build);
+        this.tokenTtl = Validate.getOrDefault(builder.getTokenTtl(), () -> DEFAULT_TOKEN_TTL);
+        this.endpoint = getEndpoint(builder);
+        this.requestMarshaller = new RequestMarshaller(this.endpoint);
+    }
+
+    private URI getEndpoint(Ec2MetadataClientBuilder<?, ?> builder) {
+        URI builderEndpoint = builder.getEndpoint();
+        EndpointMode builderEndpointMode = builder.getEndpointMode();
+        Validate.mutuallyExclusive("Only one of 'endpoint' or 'endpointMode' must be specified, but not both",
+                                   builderEndpoint, builderEndpointMode);
+        if (builderEndpoint != null) {
+            return builderEndpoint;
+        }
+        if (builderEndpointMode != null) {
+            return URI.create(DEFAULT_ENDPOINT_PROVIDER.resolveEndpoint(builderEndpointMode));
+        }
+        EndpointMode resolvedEndpointMode = DEFAULT_ENDPOINT_PROVIDER.resolveEndpointMode();
+        return URI.create(DEFAULT_ENDPOINT_PROVIDER.resolveEndpoint(resolvedEndpointMode));
+    }
+
+    protected static String uncheckedInputStreamToUtf8(AbortableInputStream inputStream) {
+        try {
+            return IoUtils.toUtf8String(inputStream);
+        } catch (IOException ioe) {
+            throw new UncheckedIOException(ioe);
+        } finally {
+            IoUtils.closeQuietly(inputStream, log.logger());
+        }
+    }
+
+}