OperationalError: attempt to write a readonly DB on Vercel via Github (the DB and its folder are ful-CodePudding

I am trying to deploy a simple Flask app with a SQLite database. It works fine when running locally. I deploy it on Vercel via Github. It works until it needs to write to the db. Then there is

OperationalError: attempt to write a readonly database

Both the DB and the folder ‘instance’ that contains it are Full-access on my local system, I can see it with

attrib ~/instance

in the command line (I am working with Windows 10). Is there a way to check and change the access mode of a file or a folder right on the Github repo?

Here are the logs regarding this error:

[ERROR] 2023-01-12T17:19:33.931Z    63bacb5b-ec13-4247-b784-9aaba99376a0
    Exception on /register [POST]Traceback (most recent call last):
  File "/var/task/sqlalchemy/engine/base.py", line 1900, in _execute_context    self.dialect.do_execute
(  File "/var/task/sqlalchemy/engine/default.py", line 736, in do_execute    cursor.execute(statement, parameters)
sqlite3.OperationalError: attempt to write a readonly database
The above exception was the direct cause of the following exception:
Traceback (most recent call last):  File "/var/task/flask/app.py", line 2525, in wsgi_app    response = self.full_dispatch_request()  File "/var/task/flask/app.py", line 1822, in full_dispatch_request    rv = self.handle_user_exception(e)  File "/var/task/flask/app.py", line 1820, in full_dispatch_request    rv = self.dispatch_request()  File "/var/task/flask/app.py", line 1796, in dispatch_request    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)  File "./app.py", line 136, in register    db.session.commit()  
File "<string>", line 2, in commit  File "/var/task/sqlalchemy/orm/session.py", line 1451, in commit    self._transaction.commit(_to_root=self.future)  File "/var/task/sqlalchemy/orm/session.py", line 829, in commit    self._prepare_impl()  File "/var/task/sqlalchemy/orm/session.py", line 808, in _prepare_impl    self.session.flush()  File "/var/task/sqlalchemy/orm/session.py", line 3444, in flush    self._flush(objects)  File "/var/task/sqlalchemy/orm/session.py", line 3584, in _flush    transaction.rollback(_capture_exception=True)  File "/var/task/sqlalchemy/util/langhelpers.py", line 70, in __exit__    compat.raise_(  File "/var/task/sqlalchemy/util/compat.py", line 211, in raise_    raise exception  File "/var/task/sqlalchemy/orm/session.py", line 3544, in _flush    flush_context.execute()  File "/var/task/sqlalchemy/orm/unitofwork.py", line 456, in execute    rec.execute(self)  File "/var/task/sqlalchemy/orm/unitofwork.py", line 630, in execute    util.preloaded.orm_persistence.save_obj(  File "/var/task/sqlalchemy/orm/persistence.py", line 245, in save_obj    _emit_insert_statements(  File "/var/task/sqlalchemy/orm/persistence.py", line 1238, in _emit_insert_statements    result = connection._execute_20(  File "/var/task/sqlalchemy/engine/base.py", line 1705, in _execute_20    return meth(self, args_10style, kwargs_10style, execution_options)  File "/var/task/sqlalchemy/sql/elements.py", line 334, in _execute_on_connection    return connection._execute_clauseelement(  File "/var/task/sqlalchemy/engine/base.py", line 1572, in _execute_clauseelement    ret = self._execute_context(  File "/var/task/sqlalchemy/engine/base.py", line 1943, in _execute_context    self._handle_dbapi_exception(  File "/var/task/sqlalchemy/engine/base.py", line 2124, in _handle_dbapi_exception    util.raise_(  File "/var/task/sqlalchemy/util/compat.py", line 211, in raise_    raise exception  File "/var/task/sqlalchemy/engine/base.py", line 1900, in _execute_context    self.dialect.do_execute(  File "/var/task/sqlalchemy/engine/default.py", line 736, in do_execute    cursor.execute(statement, parameters)sqlalchemy.exc.
OperationalError: (sqlite3.OperationalError) attempt to write a readonly database

I double-checked the access mode of the DB in my local system both as User and as Admin

CodePudding user response：

It turns out that Vercel does not support SQLite. It is clearly written in their guides:

SQLite needs a local file system on the server to store the data permanently when write requests are made. In a serverless environment, this central single permanent storage is not available because storage is ephemeral with serverless functions.

So it's not the problem of a Read-only mode, but rather the issue with SQL databases on Vercel.