Preserve original behavior, azure repo plugin

Allow plugin install even if no azure settings are present atm

Author: albertzaharovits

plugins/repository-azure/src/main/java/org/elasticsearch/repositories/azure/AzureRepositoryPlugin.java

@@ -21,6 +21,7 @@
 
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.settings.SettingsException;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.plugins.Plugin;
@@ -68,6 +69,9 @@ public List<Setting<?>> getSettings() {
     public void reload(Settings settings) {
         // secure settings should be readable
         final Map<String, AzureStorageSettings> clientsSettings = AzureStorageSettings.load(settings);
+        if (clientsSettings.isEmpty()) {
+            throw new SettingsException("If you want to use an azure repository, you need to define a client configuration.");
+        }
         azureStoreService.refreshAndClearCache(clientsSettings);
     }
 }

plugins/repository-azure/src/main/java/org/elasticsearch/repositories/azure/AzureStorageSettings.java

@@ -195,16 +195,13 @@ public static Map<String, AzureStorageSettings> load(Settings settings) {
         for (final String clientName : ACCOUNT_SETTING.getNamespaces(settings)) {
             storageSettings.put(clientName, getClientSettings(settings, clientName));
         }
-        if (storageSettings.isEmpty()) {
-            throw new SettingsException("If you want to use an azure repository, you need to define a client configuration.");
-        }
-        if (storageSettings.containsKey("default") == false) {
+        if (false == storageSettings.containsKey("default") && false == storageSettings.isEmpty()) {
             // in case no setting named "default" has been set, let's define our "default"
             // as the first named config we get
             final AzureStorageSettings defaultSettings = storageSettings.values().iterator().next();
             storageSettings.put("default", defaultSettings);
         }
-        assert storageSettings.containsKey("default") : "always have 'default'";
+        assert storageSettings.containsKey("default") || storageSettings.isEmpty() : "always have 'default' if any";
         return Collections.unmodifiableMap(storageSettings);
     }
 

plugins/repository-azure/src/test/java/org/elasticsearch/repositories/azure/AzureStorageServiceTests.java

@@ -153,11 +153,6 @@ public void testReinitClientWrongSettings() throws IOException {
         }
     }
 
-    public void testGetSelectedClientWithNoPrimaryAndSecondary() {
-        final SettingsException e = expectThrows(SettingsException.class, () -> new AzureStorageServiceImpl(Settings.EMPTY));
-        assertThat(e.getMessage(), is("If you want to use an azure repository, you need to define a client configuration."));
-    }
-
     public void testGetSelectedClientNonExisting() {
         final AzureStorageServiceImpl azureStorageService = new AzureStorageServiceImpl(buildSettings());
         final SettingsException e = expectThrows(SettingsException.class, () -> azureStorageService.client("azure4"));