Google Cloud client libraries use HTTPS and gRPC in underlying communication
with the services. In both protocols, you can configure a proxy using
https.proxyHost
and, optionally, https.proxyPort
properties.
Configure a proxy with HTTP
For HTTP clients, you can configure a basic proxy by using http.proxyHost
and
related system properties, as documented by
Java Networking and Proxies.
For a custom proxy (for example, an authenticated proxy), provide a
custom HttpTransportFactory
to GoogleCredentials
:
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.apache.v2.ApacheHttpTransport;
import com.google.auth.http.HttpTransportFactory;
import com.google.auth.oauth2.GoogleCredentials;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.routing.HttpRoutePlanner;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.ProxyAuthenticationStrategy;
import org.apache.http.impl.conn.DefaultProxyRoutePlanner;
import java.io.IOException;
public class ProxyExample {
public GoogleCredentials getCredentials() throws IOException {
HttpTransportFactory httpTransportFactory = getHttpTransportFactory(
"some-host", 8080, "some-username", "some-password"
);
return GoogleCredentials.getApplicationDefault(httpTransportFactory);
}
public HttpTransportFactory getHttpTransportFactory(String proxyHost, int proxyPort, String proxyUsername, String proxyPassword) {
HttpHost proxyHostDetails = new HttpHost(proxyHost, proxyPort);
HttpRoutePlanner httpRoutePlanner = new DefaultProxyRoutePlanner(proxyHostDetails);
CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(
new AuthScope(proxyHostDetails.getHostName(), proxyHostDetails.getPort()),
new UsernamePasswordCredentials(proxyUsername, proxyPassword)
);
HttpClient httpClient = ApacheHttpTransport.newDefaultHttpClientBuilder()
.setRoutePlanner(httpRoutePlanner)
.setProxyAuthenticationStrategy(ProxyAuthenticationStrategy.INSTANCE)
.setDefaultCredentialsProvider(credentialsProvider)
.build();
final HttpTransport httpTransport = new ApacheHttpTransport(httpClient);
return new HttpTransportFactory() {
@Override
public HttpTransport create() {
return httpTransport;
}
};
}
}
The preceding example requires com.google.http-client:google-http-client-apache-v2
.
Configure a proxy with a gRPC custom proxy configuration
For a custom proxy with gRPC, supply a ProxyDetector
to
the ManagedChannelBuilder
:
Replace PROXY_USERNAME
, PROXY_PASSWORD
, PROXY_HOST
, and PROXY_PORT
with the credentials and address of your proxy.
import com.google.api.core.ApiFunction;
import com.google.api.gax.rpc.TransportChannelProvider;
import com.google.cloud.tasks.v2.CloudTasksClient;
import com.google.cloud.tasks.v2.CloudTasksSettings;
import com.google.cloud.tasks.v2.stub.CloudTasksStubSettings;
import io.grpc.HttpConnectProxiedSocketAddress;
import io.grpc.ManagedChannelBuilder;
import io.grpc.ProxiedSocketAddress;
import io.grpc.ProxyDetector;
import javax.annotation.Nullable;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
public CloudTasksClient getService() throws IOException {
TransportChannelProvider transportChannelProvider =
CloudTasksStubSettings.defaultGrpcTransportProviderBuilder()
.setChannelConfigurator(
new ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder>() {
@Override
public ManagedChannelBuilder apply(ManagedChannelBuilder managedChannelBuilder) {
return managedChannelBuilder.proxyDetector(
new ProxyDetector() {
@Nullable
@Override
public ProxiedSocketAddress proxyFor(SocketAddress socketAddress)
throws IOException {
return HttpConnectProxiedSocketAddress.newBuilder()
.setUsername(PROXY_USERNAME)
.setPassword(PROXY_PASSWORD)
.setProxyAddress(new InetSocketAddress(PROXY_HOST, PROXY_PORT))
.setTargetAddress((InetSocketAddress) socketAddress)
.build();
}
});
}
})
.build();
CloudTasksSettings cloudTasksSettings =
CloudTasksSettings.newBuilder()
.setTransportChannelProvider(transportChannelProvider)
.build();
return CloudTasksClient.create(cloudTasksSettings);
}