Enable HTTP proxying for Netty client

.changes/next-release/feature-NettyNIOHTTPClient-8d0be28.json

@@ -0,0 +1,5 @@
+{
+    "category": "Netty NIO HTTP Client", 
+    "type": "feature", 
+    "description": "Add ability to to use HTTP proxies with the Netty async client."
+}

http-clients/netty-nio-client/src/main/java/software/amazon/awssdk/http/nio/netty/NettyNioAsyncHttpClient.java

@@ -91,6 +91,7 @@ private NettyNioAsyncHttpClient(DefaultBuilder builder, AttributeMap serviceDefa
                                              .maxStreams(maxStreams)
                                              .sdkEventLoopGroup(sdkEventLoopGroup)
                                              .sslProvider(resolveSslProvider(builder))
+                                             .proxyConfiguration(builder.proxyConfiguration)
                                              .build();
     }
 
@@ -343,6 +344,16 @@ public interface Builder extends SdkAsyncHttpClient.Builder<NettyNioAsyncHttpCli
          * @return the builder of the method chaining.
          */
         Builder sslProvider(SslProvider sslProvider);
+
+        /**
+         * Set the proxy configuration for this client. The configured proxy will be used to proxy any HTTP request
+         * destined for any host that does not match any of the hosts in configured non proxy hosts.
+         *
+         * @param proxyConfiguration The proxy configuration.
+         * @return The builder for method chaining.
+         * @see ProxyConfiguration#nonProxyHosts()
+         */
+        Builder proxyConfiguration(ProxyConfiguration proxyConfiguration);
     }
 
     /**
@@ -359,6 +370,7 @@ private static final class DefaultBuilder implements Builder {
         private SdkEventLoopGroup.Builder eventLoopGroupBuilder;
         private Integer maxHttp2Streams;
         private SslProvider sslProvider;
+        private ProxyConfiguration proxyConfiguration;
 
         private DefaultBuilder() {
         }
@@ -515,6 +527,16 @@ public void setSslProvider(SslProvider sslProvider) {
             sslProvider(sslProvider);
         }
 
+        @Override
+        public Builder proxyConfiguration(ProxyConfiguration proxyConfiguration) {
+            this.proxyConfiguration = proxyConfiguration;
+            return this;
+        }
+
+        public void setProxyConfiguration(ProxyConfiguration proxyConfiguration) {
+            proxyConfiguration(proxyConfiguration);
+        }
+
         @Override
         public SdkAsyncHttpClient buildWithDefaults(AttributeMap serviceDefaults) {
             return new NettyNioAsyncHttpClient(this, standardOptions.build()

http-clients/netty-nio-client/src/main/java/software/amazon/awssdk/http/nio/netty/ProxyConfiguration.java

@@ -0,0 +1,207 @@
+/*
+ * Copyright 2010-2019 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.http.nio.netty;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import software.amazon.awssdk.annotations.SdkPublicApi;
+import software.amazon.awssdk.utils.builder.CopyableBuilder;
+import software.amazon.awssdk.utils.builder.ToCopyableBuilder;
+
+/**
+ * Proxy configuration for {@link NettyNioAsyncHttpClient}. This class is used to configure an HTTP proxy to be used by
+ * the {@link NettyNioAsyncHttpClient}.
+ *
+ * @see NettyNioAsyncHttpClient.Builder#proxyConfiguration(ProxyConfiguration)
+ */
+@SdkPublicApi
+public final class ProxyConfiguration implements ToCopyableBuilder<ProxyConfiguration.Builder, ProxyConfiguration> {
+    private final String scheme;
+    private final String host;
+    private final int port;
+    private final Set<String> nonProxyHosts;
+
+    private ProxyConfiguration(BuilderImpl builder) {
+        this.scheme = builder.scheme;
+        this.host = builder.host;
+        this.port = builder.port;
+        this.nonProxyHosts = Collections.unmodifiableSet(builder.nonProxyHosts);
+    }
+
+    /**
+     * @return The proxy scheme.
+     */
+    public String scheme() {
+        return scheme;
+    }
+
+    /**
+     * @return The proxy host.
+     */
+    public String host() {
+        return host;
+    }
+
+    /**
+     * @return The proxy port.
+     */
+    public int port() {
+        return port;
+    }
+
+    /**
+     * @return The set of hosts that should not be proxied.
+     */
+    public Set<String> nonProxyHosts() {
+        return nonProxyHosts;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        ProxyConfiguration that = (ProxyConfiguration) o;
+
+        if (port != that.port) {
+            return false;
+        }
+
+        if (scheme != null ? !scheme.equals(that.scheme) : that.scheme != null) {
+            return false;
+        }
+
+        if (host != null ? !host.equals(that.host) : that.host != null) {
+            return false;
+        }
+
+        return nonProxyHosts.equals(that.nonProxyHosts);
+
+    }
+
+    @Override
+    public int hashCode() {
+        int result = scheme != null ? scheme.hashCode() : 0;
+        result = 31 * result + (host != null ? host.hashCode() : 0);
+        result = 31 * result + port;
+        result = 31 * result + nonProxyHosts.hashCode();
+        return result;
+    }
+
+    @Override
+    public Builder toBuilder() {
+        return new BuilderImpl(this);
+    }
+
+    public static Builder builder() {
+        return new BuilderImpl();
+    }
+
+    /**
+     * Builder for {@link ProxyConfiguration}.
+     */
+    public interface Builder extends CopyableBuilder<Builder, ProxyConfiguration> {
+
+        /**
+         * Set the hostname of the proxy.
+         * @param host The proxy host.
+         * @return This object for method chaining.
+         */
+        Builder host(String host);
+
+        /**
+         * Set the port that the proxy expects connections on.
+         * @param port The proxy port.
+         * @return This object for method chaining.
+         */
+        Builder port(int port);
+
+        /**
+         * The HTTP scheme to use for connecting to the proxy. Valid values are {@code http} and {@code https}.
+         * <p>
+         * The client defaults to {@code http} if none is given.
+         *
+         * @param scheme The proxy scheme.
+         * @return This object for method chaining.
+         */
+        Builder scheme(String scheme);
+
+        /**
+         * Set the set of hosts that should not be proxied. Any request whose host portion matches any of the patterns
+         * given in the set will be sent to the remote host directly instead of through the proxy.
+         *
+         * @param nonProxyHosts The set of hosts that should not be proxied.
+         * @return This object for method chaining.
+         */
+        Builder nonProxyHosts(Set<String> nonProxyHosts);
+    }
+
+    private static final class BuilderImpl implements Builder {
+        private String scheme;
+        private String host;
+        private int port;
+        private Set<String> nonProxyHosts = Collections.emptySet();
+
+        private BuilderImpl() {
+        }
+
+        private BuilderImpl(ProxyConfiguration proxyConfiguration) {
+            this.scheme = proxyConfiguration.scheme;
+            this.host = proxyConfiguration.host;
+            this.port = proxyConfiguration.port;
+            this.nonProxyHosts = new HashSet<>(proxyConfiguration.nonProxyHosts);
+        }
+
+        @Override
+        public Builder scheme(String scheme) {
+            this.scheme = scheme;
+            return this;
+        }
+
+        @Override
+        public Builder host(String host) {
+            this.host = host;
+            return this;
+        }
+
+        @Override
+        public Builder port(int port) {
+            this.port = port;
+            return this;
+        }
+
+        @Override
+        public Builder nonProxyHosts(Set<String> nonProxyHosts) {
+            if (nonProxyHosts != null) {
+                this.nonProxyHosts = new HashSet<>(nonProxyHosts);
+            } else {
+                this.nonProxyHosts = Collections.emptySet();
+            }
+            return this;
+        }
+
+        @Override
+        public ProxyConfiguration build() {
+            return new ProxyConfiguration(this);
+        }
+    }
+}