code refactor to handle edge cases

Author: sagnghos

google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java

@@ -58,6 +58,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
+import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
@@ -810,18 +811,6 @@ protected SpannerOptions(Builder builder) {
     enableBuiltInMetrics = builder.enableBuiltInMetrics;
     enableEndToEndTracing = builder.enableEndToEndTracing;
     monitoringHost = builder.monitoringHost;
-    String externalHostTokenPath = System.getenv("SPANNER_EXTERNAL_HOST_AUTH_TOKEN");
-    if (builder.isExternalHost && builder.emulatorHost == null && externalHostTokenPath != null) {
-      String token;
-      try {
-        token =
-            Base64.getEncoder()
-                .encodeToString(Files.readAllBytes(Paths.get(externalHostTokenPath)));
-      } catch (IOException e) {
-        throw SpannerExceptionFactory.newSpannerException(e);
-      }
-      credentials = new GoogleCredentials(new AccessToken(token, null));
-    }
   }
 
   /**
@@ -1483,7 +1472,7 @@ public Builder setDecodeMode(DecodeMode decodeMode) {
     @Override
     public Builder setHost(String host) {
       super.setHost(host);
-      if (this.emulatorHost == null && !CLOUD_SPANNER_HOST_PATTERN.matcher(host).matches()) {
+      if (!CLOUD_SPANNER_HOST_PATTERN.matcher(host).matches()) {
         this.isExternalHost = true;
       }
       // Setting a host should override any SPANNER_EMULATOR_HOST setting.
@@ -1656,6 +1645,19 @@ public SpannerOptions build() {
         this.setChannelConfigurator(ManagedChannelBuilder::usePlaintext);
         // As we are using plain text, we should never send any credentials.
         this.setCredentials(NoCredentials.getInstance());
+      } else if (isExternalHost && credentials == null) {
+        String externalHostTokenPath = System.getenv("SPANNER_EXTERNAL_HOST_AUTH_TOKEN");
+        if (!Strings.isNullOrEmpty(externalHostTokenPath)) {
+          String token;
+          try {
+            token =
+                Base64.getEncoder()
+                    .encodeToString(Files.readAllBytes(Paths.get(externalHostTokenPath)));
+          } catch (IOException e) {
+            throw SpannerExceptionFactory.newSpannerException(e);
+          }
+          credentials = GoogleCredentials.create(new AccessToken(token, null));
+        }
       }
       if (this.numChannels == null) {
         this.numChannels =

google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ConnectionOptions.java

@@ -82,9 +82,12 @@
 import io.opentelemetry.api.OpenTelemetry;
 import java.io.IOException;
 import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Base64;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -921,6 +924,7 @@ private ConnectionOptions(Builder builder) {
             getInitialConnectionPropertyValue(AUTO_CONFIG_EMULATOR),
             usePlainText,
             System.getenv());
+    String externalHostTokenPath = System.getenv("SPANNER_EXTERNAL_HOST_AUTH_TOKEN");
     // Using credentials on a plain text connection is not allowed, so if the user has not specified
     // any credentials and is using a plain text connection, we should not try to get the
     // credentials from the environment, but default to NoCredentials.
@@ -935,6 +939,16 @@ && getInitialConnectionPropertyValue(OAUTH_TOKEN) == null
       this.credentials =
           new GoogleCredentials(
               new AccessToken(getInitialConnectionPropertyValue(OAUTH_TOKEN), null));
+    } else if (isExternalHost && !Strings.isNullOrEmpty(externalHostTokenPath)) {
+      String token;
+      try {
+        token =
+            Base64.getEncoder()
+                .encodeToString(Files.readAllBytes(Paths.get(externalHostTokenPath)));
+      } catch (IOException e) {
+        throw SpannerExceptionFactory.newSpannerException(e);
+      }
+      this.credentials = GoogleCredentials.create(new AccessToken(token, null));
     } else if (getInitialConnectionPropertyValue(CREDENTIALS_PROVIDER) != null) {
       try {
         this.credentials = getInitialConnectionPropertyValue(CREDENTIALS_PROVIDER).getCredentials();

google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/SpannerPool.java

@@ -407,9 +407,6 @@ Spanner createSpanner(SpannerPoolKey key, ConnectionOptions options) {
     if (options.getConfigurator() != null) {
       options.getConfigurator().configure(builder);
     }
-    if (options.usesEmulator()) {
-      builder.setEmulatorHost(key.host);
-    }
     return builder.build().getService();
   }