Oss support opendal(including mysql) (#8204)

### What problem does this PR solve?

#8074
Oss support opendal(including mysql)

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

rag/utils/opendal_conn.py

@@ -0,0 +1,115 @@
+import opendal
+import logging
+import pymysql
+import yaml
+
+from rag.utils import singleton
+
+SERVICE_CONF_PATH = "conf/service_conf.yaml"
+
+CREATE_TABLE_SQL = """
+CREATE TABLE IF NOT EXISTS `{}` (
+    `key` VARCHAR(255) PRIMARY KEY,
+    `value` LONGBLOB,
+    `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    `updated_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
+);
+"""
+SET_MAX_ALLOWED_PACKET_SQL = """
+SET GLOBAL max_allowed_packet={}
+"""
+
+
+def get_opendal_config_from_yaml(yaml_path=SERVICE_CONF_PATH):
+    try:
+        with open(yaml_path, 'r') as f:
+            config = yaml.safe_load(f)
+
+        opendal_config = config.get('opendal', {})
+        kwargs = {}
+        if opendal_config.get("schema") == 'mysql':
+            mysql_config = config.get('mysql', {})
+            kwargs = {
+                "schema": "mysql",
+                "host": mysql_config.get("host", "127.0.0.1"),
+                "port": str(mysql_config.get("port", 3306)),
+                "user": mysql_config.get("user", "root"),
+                "password": mysql_config.get("password", ""),
+                "database": mysql_config.get("name", "test_open_dal"),
+                "table": opendal_config.get("config").get("table", "opendal_storage")
+            }
+            kwargs["connection_string"] = f"mysql://{kwargs['user']}:{kwargs['password']}@{kwargs['host']}:{kwargs['port']}/{kwargs['database']}"
+        else:
+            schema = opendal_config.get("schema")
+            config_data = opendal_config.get("config", {})
+            kwargs = {"schema": schema, **config_data}
+        logging.info("Loaded OpenDAL configuration from yaml: %s", kwargs)
+        return kwargs
+    except Exception as e:
+        logging.error("Failed to load OpenDAL configuration from yaml: %s", str(e))
+        raise
+
+
+@singleton
+class OpenDALStorage:
+    def __init__(self):
+        self._kwargs = get_opendal_config_from_yaml()
+        self._schema = self._kwargs.get('schema', 'mysql')
+        if self._schema == 'mysql':
+            self.init_db_config()
+            self.init_opendal_mysql_table()
+        self._operator = opendal.Operator(self._schema, **self._kwargs)
+
+        logging.info("OpenDALStorage initialized successfully")
+
+    def put(self, bucket, fnm, binary):
+        self._operator.write(f"{bucket}/{fnm}", binary)
+
+    def get(self, bucket, fnm):
+        return self._operator.read(f"{bucket}/{fnm}")
+
+    def rm(self, bucket, fnm):
+        self._operator.delete(f"{bucket}/{fnm}")
+        self._operator.__init__()
+
+    def scan(self, bucket, fnm):
+        return self._operator.scan(f"{bucket}/{fnm}")
+
+    def obj_exist(self, bucket, fnm):
+        return self._operator.exists(f"{bucket}/{fnm}")
+
+
+    def init_db_config(self):
+        try:
+            conn = pymysql.connect(
+                host=self._kwargs['host'],
+                port=int(self._kwargs['port']),
+                user=self._kwargs['user'],
+                password=self._kwargs['password'],
+                database=self._kwargs['database']
+            )
+            cursor = conn.cursor()
+            max_packet = self._kwargs.get('max_allowed_packet', 4194304)  # Default to 4MB if not specified
+            cursor.execute(SET_MAX_ALLOWED_PACKET_SQL.format(max_packet))
+            conn.commit()
+            cursor.close()
+            conn.close()
+            logging.info(f"Database configuration initialized with max_allowed_packet={max_packet}")
+        except Exception as e:
+            logging.error(f"Failed to initialize database configuration: {str(e)}")
+            raise
+
+    def init_opendal_mysql_table(self):
+        conn = pymysql.connect(
+            host=self._kwargs['host'],
+            port=int(self._kwargs['port']),
+            user=self._kwargs['user'],
+            password=self._kwargs['password'],
+            database=self._kwargs['database']
+        )
+        cursor = conn.cursor()
+        cursor.execute(CREATE_TABLE_SQL.format(self._kwargs['table']))
+        conn.commit()
+        cursor.close()
+        conn.close()
+        logging.info(f"Table `{self._kwargs['table']}` initialized.")

rag/utils/storage_factory.py

@@ -20,6 +20,7 @@ from enum import Enum
 from rag.utils.azure_sas_conn import RAGFlowAzureSasBlob
 from rag.utils.azure_spn_conn import RAGFlowAzureSpnBlob
 from rag.utils.minio_conn import RAGFlowMinio
+from rag.utils.opendal_conn import OpenDALStorage
 from rag.utils.s3_conn import RAGFlowS3
 from rag.utils.oss_conn import RAGFlowOSS
 
@@ -30,6 +31,7 @@ class Storage(Enum):
     AZURE_SAS = 3
     AWS_S3 = 4
     OSS = 5
+    OPENDAL = 6
 
 
 class StorageFactory:
@@ -39,6 +41,7 @@ class StorageFactory:
         Storage.AZURE_SAS: RAGFlowAzureSasBlob,
         Storage.AWS_S3: RAGFlowS3,
         Storage.OSS: RAGFlowOSS,
+        Storage.OPENDAL: OpenDALStorage
     }
 
     @classmethod