feat: enable reuse for mongodb

Author: BounkongK

modules/mongodb/src/main/java/org/testcontainers/containers/MongoDBContainer.java

@@ -130,19 +130,23 @@ private void checkMongoNodeExitCodeAfterWaiting(final Container.ExecResult execR
 
     @SneakyThrows(value = { IOException.class, InterruptedException.class })
     private void initReplicaSet() {
-        log.debug("Initializing a single node node replica set...");
-        final ExecResult execResultInitRs = execInContainer(buildMongoEvalCommand("rs.initiate();"));
-        log.debug(execResultInitRs.getStdout());
-        checkMongoNodeExitCode(execResultInitRs);
-
-        log.debug(
-            "Awaiting for a single node replica set initialization up to {} attempts",
-            AWAIT_INIT_REPLICA_SET_ATTEMPTS
-        );
-        final ExecResult execResultWaitForMaster = execInContainer(buildMongoEvalCommand(buildMongoWaitCommand()));
-        log.debug(execResultWaitForMaster.getStdout());
+        if (isReplicationSetAlreadyInitialized()) {
+            log.debug("Replica set already initialized.");
+        } else {
+            log.debug("Initializing a single node node replica set...");
+            final ExecResult execResultInitRs = execInContainer(buildMongoEvalCommand("rs.initiate();"));
+            log.debug(execResultInitRs.getStdout());
+            checkMongoNodeExitCode(execResultInitRs);
+
+            log.debug(
+                "Awaiting for a single node replica set initialization up to {} attempts",
+                AWAIT_INIT_REPLICA_SET_ATTEMPTS
+            );
+            final ExecResult execResultWaitForMaster = execInContainer(buildMongoEvalCommand(buildMongoWaitCommand()));
+            log.debug(execResultWaitForMaster.getStdout());
 
-        checkMongoNodeExitCodeAfterWaiting(execResultWaitForMaster);
+            checkMongoNodeExitCodeAfterWaiting(execResultWaitForMaster);
+        }
     }
 
     public static class ReplicaSetInitializationException extends RuntimeException {
@@ -151,4 +155,10 @@ public static class ReplicaSetInitializationException extends RuntimeException {
             super(errorMessage);
         }
     }
+
+    private boolean isReplicationSetAlreadyInitialized() {
+        // since we are creating a replica set with one node, this node must be primary (state = 1)
+        final ExecResult execCheckRsInit = execInContainer(buildMongoEvalCommand("if(db.adminCommand({replSetGetStatus: 1})['myState'] != 1) quit(900)"));
+        return execCheckRsInit.getExitCode() == CONTAINER_EXIT_CODE_OK;
+    }
 }