Fix native compilation for Google PubSub extension

Fixes #3832

extensions/google-pubsub/runtime/pom.xml

@@ -77,6 +77,11 @@
             <groupId>org.apache.camel</groupId>
             <artifactId>camel-google-pubsub</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.graalvm.nativeimage</groupId>
+            <artifactId>svm</artifactId>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 
     <build>

extensions/google-pubsub/runtime/src/main/java/org/apache/camel/quarkus/component/google/pubsub/graalvm/GaxGrpcSubstitutions.java

@@ -0,0 +1,167 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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
+ *
+ *      http://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 org.apache.camel.quarkus.component.google.pubsub.graalvm;
+
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.gax.grpc.ChannelPrimer;
+import com.google.api.gax.grpc.GrpcHeaderInterceptor;
+import com.google.api.gax.grpc.GrpcInterceptorProvider;
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.api.gax.rpc.HeaderProvider;
+import com.oracle.svm.core.annotate.Alias;
+import com.oracle.svm.core.annotate.Substitute;
+import com.oracle.svm.core.annotate.TargetClass;
+import io.grpc.CallOptions;
+import io.grpc.Channel;
+import io.grpc.ChannelCredentials;
+import io.grpc.ClientCall;
+import io.grpc.ClientInterceptor;
+import io.grpc.Grpc;
+import io.grpc.ManagedChannel;
+import io.grpc.ManagedChannelBuilder;
+import io.grpc.MethodDescriptor;
+import org.threeten.bp.Duration;
+
+/**
+ * Cut out unsupported and optional features that are only present in grpc-alts.
+ *
+ * Camel Google PubSub only requires access to FixedTransportChannelProvider, but we leave
+ * InstantiatingGrpcChannelProvider in a functional state in case some other library
+ * needs to use it.
+ */
+final class GaxGrpcSubstitutions {
+}
+
+@TargetClass(InstantiatingGrpcChannelProvider.class)
+final class InstantiatingGrpcChannelProviderSubstitutions {
+    @Alias
+    private Executor executor;
+    @Alias
+    private HeaderProvider headerProvider;
+    @Alias
+    private GrpcInterceptorProvider interceptorProvider;
+    @Alias
+    private String endpoint;
+    @Alias
+    private Integer maxInboundMessageSize;
+    @Alias
+    private Integer maxInboundMetadataSize;
+    @Alias
+    private Duration keepAliveTime;
+    @Alias
+    private Duration keepAliveTimeout;
+    @Alias
+    private Boolean keepAliveWithoutCalls;
+    @Alias
+    private ChannelPrimer channelPrimer;
+    @Alias
+    private ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> channelConfigurator;
+
+    @Substitute
+    private ManagedChannel createSingleChannel() throws IOException {
+        GrpcHeaderInterceptor headerInterceptor = new GrpcHeaderInterceptor(headerProvider.getHeaders());
+        ClientInterceptor metadataHandlerInterceptor = new GrpcMetadataHandlerInterceptorTarget();
+
+        int colon = endpoint.lastIndexOf(':');
+        if (colon < 0) {
+            throw new IllegalStateException("invalid endpoint - should have been validated: " + endpoint);
+        }
+        int port = Integer.parseInt(endpoint.substring(colon + 1));
+        String serviceAddress = endpoint.substring(0, colon);
+
+        ManagedChannelBuilder<?> builder;
+        ChannelCredentials channelCredentials;
+        try {
+            channelCredentials = createMtlsChannelCredentials();
+        } catch (GeneralSecurityException e) {
+            throw new IOException(e);
+        }
+
+        if (channelCredentials != null) {
+            builder = Grpc.newChannelBuilder(endpoint, channelCredentials);
+        } else {
+            builder = ManagedChannelBuilder.forAddress(serviceAddress, port);
+        }
+
+        builder.disableServiceConfigLookUp();
+
+        builder = builder.intercept(new GrpcChannelUUIDInterceptorTarget())
+                .intercept(headerInterceptor)
+                .intercept(metadataHandlerInterceptor)
+                .userAgent(headerInterceptor.getUserAgentHeader())
+                .executor(executor);
+
+        if (maxInboundMetadataSize != null) {
+            builder.maxInboundMetadataSize(maxInboundMetadataSize);
+        }
+        if (maxInboundMessageSize != null) {
+            builder.maxInboundMessageSize(maxInboundMessageSize);
+        }
+        if (keepAliveTime != null) {
+            builder.keepAliveTime(keepAliveTime.toMillis(), TimeUnit.MILLISECONDS);
+        }
+        if (keepAliveTimeout != null) {
+            builder.keepAliveTimeout(keepAliveTimeout.toMillis(), TimeUnit.MILLISECONDS);
+        }
+        if (keepAliveWithoutCalls != null) {
+            builder.keepAliveWithoutCalls(keepAliveWithoutCalls);
+        }
+        if (interceptorProvider != null) {
+            builder.intercept(interceptorProvider.getInterceptors());
+        }
+        if (channelConfigurator != null) {
+            builder = channelConfigurator.apply(builder);
+        }
+
+        ManagedChannel managedChannel = builder.build();
+        if (channelPrimer != null) {
+            channelPrimer.primeChannel(managedChannel);
+        }
+        return managedChannel;
+    }
+
+    @Alias
+    ChannelCredentials createMtlsChannelCredentials() throws IOException, GeneralSecurityException {
+        throw new UnsupportedOperationException();
+    }
+}
+
+@TargetClass(className = "com.google.api.gax.grpc.GrpcMetadataHandlerInterceptor")
+final class GrpcMetadataHandlerInterceptorTarget implements ClientInterceptor {
+
+    @Alias()
+    @Override
+    public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> method,
+            final CallOptions callOptions, Channel next) {
+        throw new UnsupportedOperationException();
+    }
+}
+
+@TargetClass(className = "com.google.api.gax.grpc.GrpcChannelUUIDInterceptor")
+final class GrpcChannelUUIDInterceptorTarget implements ClientInterceptor {
+    @Alias
+    @Override
+    public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> methodDescriptor,
+            CallOptions callOptions, Channel channel) {
+        throw new UnsupportedOperationException();
+    }
+}

integration-tests/google-pubsub/pom.xml

@@ -69,7 +69,6 @@
         </dependency>
     </dependencies>
     <profiles>
-        <!-- TODO: https://github.com/apache/camel-quarkus/issues/3832
         <profile>
             <id>native</id>
             <activation>
@@ -97,7 +96,6 @@
                 </plugins>
             </build>
         </profile>
-        -->
         <profile>
             <id>virtualDependencies</id>
             <activation>