chore: Add mongo data migration check before initializing the postgres dump

deploy/docker/fs/opt/appsmith/utils/bin/move-to-postgres.mjs

@@ -18,6 +18,11 @@ let mongoDbUrl;
 let mongoDumpFile = null;
 const EXPORT_ROOT = "/appsmith-stacks/mongo-data";
 
+// The minimum version of the MongoDB changeset that must be present in the mongockChangeLog collection to run this script.
+// This is to ensure we are migrating the data from the stable version of MongoDB.
+const MINIMUM_MONGO_CHANGESET = "add_empty_policyMap_for_null_entries";
+const MONGO_MIGRATION_COLLECTION = "mongockChangeLog";
+
 for (let i = 2; i < process.argv.length; ++i) {
   const arg = process.argv[i];
   if (arg.startsWith("--mongodb-url=") && !mongoDbUrl) {
@@ -77,6 +82,15 @@ if (isBaselineMode) {
 const collectionNames = await mongoDb.listCollections({}, { nameOnly: true }).toArray();
 const sortedCollectionNames = collectionNames.map(collection => collection.name).sort();
 
+// Verify that the MongoDB data has been migrated to a stable version i.e. v1.43 before we start migrating the data to Postgres.
+if (!await isMongoDataMigratedToStableVersion(mongoDb)) {
+  console.error("MongoDB migration check failed: Try upgrading the Appsmith instance to latest before opting for data migration.");
+  console.error(`Could not find the valid migration execution entry for "${MINIMUM_MONGO_CHANGESET}" in the "${MONGO_MIGRATION_COLLECTION}" collection.`);
+  await mongoClient.close();
+  mongoServer?.kill();
+  process.exit(1);
+}
+
 for await (const collectionName of sortedCollectionNames) {
 
   console.log("Collection:", collectionName);
@@ -183,3 +197,16 @@ function mapClassToType(_class) {
       return null;
   }
 }
+
+/**
+ * Method to check if MongoDB data has migrated to a stable version before we start migrating the data to Postgres.
+ * @param {*} mongoDb - The MongoDB client.
+ * @returns {Promise<boolean>} - A promise that resolves to true if the data has been migrated to a stable version, false otherwise.
+ */
+async function isMongoDataMigratedToStableVersion(mongoDb) {
+  const doc = await mongoDb.collection(MONGO_MIGRATION_COLLECTION).findOne({
+    changeId: MINIMUM_MONGO_CHANGESET,
+    state: "EXECUTED",
+  });
+  return doc !== null;
+}