Check service configurations in verify phase

service/pom.xml

@@ -593,6 +593,28 @@
           </execution>
         </executions>
       </plugin>
+
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>3.0.0</version>
+        <executions>
+          <execution>
+            <id>check-all-service-config</id>
+            <phase>verify</phase>
+            <goals>
+              <goal>java</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <mainClass>org.whispersystems.textsecuregcm.CheckServiceConfigurations</mainClass>
+          <classpathScope>test</classpathScope>
+          <arguments>
+            <argument>${project.basedir}/config</argument>
+          </arguments>
+        </configuration>
+      </plugin>
     </plugins>
   </build>
 </project>

service/src/test/java/org/whispersystems/textsecuregcm/CheckServiceConfigurations.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2021 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm;
+
+import java.io.File;
+import java.util.Arrays;
+
+/**
+ * Checks whether all YAML configuration files in a given directory are valid.
+ * <p>
+ * Note: the current implementation fails fast, rather than reporting multiple invalid files
+ */
+public class CheckServiceConfigurations {
+
+  private void checkConfiguration(final File configDirectory) {
+
+    final File[] configFiles = configDirectory.listFiles(f ->
+        !f.isDirectory()
+            && f.getPath().endsWith(".yml"));
+
+    if (configFiles == null || configFiles.length == 0) {
+      throw new IllegalArgumentException("No .yml configuration files found at " + configDirectory.getPath());
+    }
+
+    for (File configFile : configFiles) {
+      String[] args = new String[]{"check", configFile.getAbsolutePath()};
+
+      try {
+        new WhisperServerService().run(args);
+      } catch (final Exception e) {
+        // Invalid configuration will cause the "check" command to call `System.exit()`, rather than throwing,
+        // so this is unexpected
+        throw new RuntimeException(e);
+      }
+    }
+  }
+
+  public static void main(String[] args) {
+
+    if (args.length != 1) {
+      throw new IllegalArgumentException("Expected single argument with config directory: " + Arrays.toString(args));
+    }
+
+    final File configDirectory = new File(args[0]);
+
+    if (!(configDirectory.exists() && configDirectory.isDirectory())) {
+      throw new IllegalArgumentException("No directory found at " + configDirectory.getPath());
+    }
+
+    new CheckServiceConfigurations().checkConfiguration(configDirectory);
+  }
+
+}