chore: add a runnable tool that can we used to debug gRPC connection issues (#80)

* chore: add a runnable tool that can we used to debug gRPC connection issues

* better messaging

Author: igorbernstein2

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/misc_utilities/SimpleGceRawRead.java

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+/*
+ * Copyright 2019 Google LLC
+ *
+ * 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 com.google.cloud.bigtable.misc_utilities;
+
+import com.google.bigtable.v2.BigtableGrpc;
+import com.google.bigtable.v2.ReadRowsRequest;
+import com.google.bigtable.v2.ReadRowsResponse;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Lists;
+import io.grpc.ManagedChannel;
+import io.grpc.alts.ComputeEngineChannelBuilder;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.logging.ConsoleHandler;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Simple utility to debug connection issues.
+ *
+ * <p>It enables verbose gRPC logging and does a simple read using a GCE channel builder.
+ *
+ * <pre>{@code
+ * mvn install
+ *
+ * mvn test-compile exec:java \
+ *   -pl google-cloud-bigtable \
+ *   -Dexec.mainClass=com.google.cloud.bigtable.misc_utilities.SimpleGceRawRead \
+ *   -Dexec.classpathScope=test \
+ *   -Dbigtable.project=gcloud-devel \
+ *   -Dbigtable.instance=google-cloud-bigtable \
+ *   -Dbigtable.table=integration-tests \
+ *   -Dbigtable.data-endpoint="bigtable.googleapis.com"
+ * }</pre>
+ */
+public class SimpleGceRawRead {
+
+  public static void main(String[] args) {
+    configureLogging();
+
+    String projectId = System.getProperty("bigtable.project", "gcloud-devel");
+    String instanceId = System.getProperty("bigtable.instance", "google-cloud-bigtable");
+    String tableId = System.getProperty("bigtable.table", "integration-tests");
+
+    String endpoint = System.getProperty("bigtable.data-endpoint", "bigtable.googleapis.com");
+    String tableName =
+        String.format("projects/%s/instances/%s/tables/%s", projectId, instanceId, tableId);
+
+    System.out.printf(">>>>>>>>> Trying to connect to: %s, to read %s%n%n%n", endpoint, tableName);
+
+    ManagedChannel channel =
+        ComputeEngineChannelBuilder.forAddress(endpoint, 443)
+            .disableServiceConfigLookUp()
+            .defaultServiceConfig(newServiceConfig())
+            .build();
+    try {
+      BigtableGrpc.BigtableBlockingStub stub = BigtableGrpc.newBlockingStub(channel);
+
+      Iterator<ReadRowsResponse> iter =
+          stub.readRows(
+              ReadRowsRequest.newBuilder().setTableName(tableName).setRowsLimit(1).build());
+      System.out.printf("%n%n>>>>>>>>> Success Rows Read: %d%n%n", Lists.newArrayList(iter).size());
+    } finally {
+      channel.shutdown();
+    }
+  }
+
+  /** Enable verbose gRPC logging */
+  private static void configureLogging() {
+    Logger.getLogger("io.grpc").setLevel(Level.ALL);
+    Logger.getLogger("io.grpc.netty.shaded").setLevel(Level.ALL);
+
+    ConsoleHandler stderr = new ConsoleHandler();
+    stderr.setLevel(Level.ALL);
+
+    Logger.getLogger("").addHandler(stderr);
+  }
+
+  private static Map<String, Object> newServiceConfig() {
+    ImmutableMap<String, Object> pickFirstStrategy =
+        ImmutableMap.<String, Object>of("pick_first", ImmutableMap.of());
+    ImmutableMap<String, Object> childPolicy =
+        ImmutableMap.<String, Object>of("childPolicy", ImmutableList.of(pickFirstStrategy));
+    ImmutableMap<String, Object> grpcLbPolicy =
+        ImmutableMap.<String, Object>of("grpclb", childPolicy);
+    return ImmutableMap.<String, Object>of("loadBalancingConfig", ImmutableList.of(grpcLbPolicy));
+  }
+}

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/misc_utilities/package-info.java

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+/*
+ * Copyright 2019 Google LLC
+ *
+ * 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.
+ */
+/**
+ * Miscellaneous developer utilities that can be executed by the developer to debug issues.
+ *
+ * <p>These are not meant to be used as automated tests, but more so for interactive use to debug
+ * issues.
+ */
+package com.google.cloud.bigtable.misc_utilities;