Flask-SQLAlchemy deployment error: Read-only file system at /var/task/instance

My code:

from flask import Flask, render_template, url_for
from flask import request, flash, redirect, session, abort
from flask_login import login_user, logout_user, login_required, current_user, UserMixin
from werkzeug.security import check_password_hash, generate_password_hash
from flask_sqlalchemy import SQLAlchemy
from flask_admin import Admin
from flask_admin.contrib.sqla import ModelView
from flask_login import LoginManager, UserMixin
import os

app = Flask(__name__)

app.config["SQLALCHEMY_DATABASE_URI"] = 'sqlite:///nexus.db'

nexusdb = SQLAlchemy(app)
lm = LoginManager(app)

mem0_dir = os.environ.get("MEM0_DIR", "/tmp/.mem0")

class Users (nexusdb.Model, UserMixin):
    __tablename__ = 'users'
    id = nexusdb.Column(nexusdb.Integer, primary_key=True)
    login = nexusdb.Column(nexusdb.String(128), nullable=False)
    password = nexusdb.Column(nexusdb.String(255), nullable=False)
    description = nexusdb.Column(nexusdb.String(255), default="Нет описания...")
    is_admin = nexusdb.Column(nexusdb.String(18), default="FALSE")

class Posts (nexusdb.Model):
    __tablename__ = 'posts'
    id = nexusdb.Column(nexusdb.Integer, primary_key=True)
    user_name = nexusdb.Column(nexusdb.Integer, nexusdb.ForeignKey('users.id'))
    text = nexusdb.Column(nexusdb.Text, nullable=False)
    name = nexusdb.Column(nexusdb.String(64), nullable=False)
    board = nexusdb.Column(nexusdb.String(64), nullable=False)

class Comments (nexusdb.Model):
    __tablename__ = 'comments'
    id = nexusdb.Column(nexusdb.Integer, primary_key=True)
    user_name = nexusdb.Column(nexusdb.Integer, nexusdb.ForeignKey('users.id'))
    post_id = nexusdb.Column(nexusdb.Integer, nexusdb.ForeignKey('posts.id'))
    text = nexusdb.Column(nexusdb.Text, nullable=False)

def CREATE_ALL():
    with app.app_context():
        nexusdb.create_all()

admin = Admin(app, name="Админ-панель")
app.secret_key = "salty_web3418"

@lm.user_loader
def load_user(user_id):
    return Users.query.get(user_id)

@app.route("/")
def homeRedirect():
    return redirect("/home")

@app.route("/home")
def home():
    l = current_user.is_authenticated
    p = Posts.query.limit(3).all()
    return render_template("home.html", loginned=l, posts = p)

@app.route("/boards")
def boards():
    l = current_user.is_authenticated
    return render_template("boards.html", loginned=l)

@app.route("/boards/random", methods=['GET', 'POST'])
@login_required
def boards_random():

    if request.method == "POST":
        postname = request.form.get("RandomPostName")
        posttext = request.form.get("RandomPostText")

        if not postname or not posttext:
            print("ERROR: Имя или текст поста неправельны!")
        
        post = Posts(name = postname, text = posttext, board = "random", user_name = current_user.login)

        nexusdb.session.add(post)
        nexusdb.session.commit()
        return redirect("/boards/random")
    
    else:
        posts = Posts.query.filter_by(board = "random").order_by(Posts.name).all()
        return render_template("random-b.html", posts = posts)

@app.route("/boards/clean", methods=['GET', 'POST'])
@login_required
def boards_clean():
    if request.method == "POST":
        postname = request.form.get("CleanPostName")
        posttext = request.form.get("CleanPostText")

        if not postname or not posttext:
            print("ERROR: Имя или текст поста неправельны!")
        
        post = Posts(name = postname, text = posttext, board = "clean", user_name = current_user.login)

        nexusdb.session.add(post)
        nexusdb.session.commit()
        return redirect("/boards/clean")
    
    else:
        posts = Posts.query.filter_by(board = "clean").order_by(Posts.name).all()
        return render_template("clean-b.html", posts = posts)

@app.route("/boards/creative", methods=['GET', 'POST'])
@login_required
def boards_creative():
    if request.method == "POST":
        postname = request.form.get("CreativePostName")
        posttext = request.form.get("CreativePostText")

        if not postname or not posttext:
            print("ERROR: Имя или текст поста неправельны!")
        
        post = Posts(name = postname, text = posttext, board = "creative", user_name = current_user.login)

        nexusdb.session.add(post)
        nexusdb.session.commit()
        return redirect("/boards/creative")
    
    else:
        posts = Posts.query.filter_by(board = "creative").order_by(Posts.name).all()
        return render_template("creative-b.html", posts = posts)

@app.route("/user", methods=['GET', 'POST'])
@login_required
def user():
    user = current_user
    
    if request.method == 'POST':
        newlogin = request.form.get("userName")
        newdes = request.form.get("userDes")

        user.login = newlogin
        user.description = newdes

        nexusdb.session.commit()

        newuser = current_user
        return render_template("user.html", u=newuser)

    return render_template("user.html", u=user)

@app.route("/login", methods=['GET', 'POST'])
def login():
    login = request.form.get("loginName")
    password = request.form.get("loginPassword")

    if request.method == "POST":
        if login and password:
            user = Users.query.filter_by(login=login).first()

            if user and check_password_hash(user.password, password):
                login_user(user)

                return redirect("/home")
            else:
                print("ERROR: Логин или пароль неправельны!")
        else:
            print("ERROR: Логин и пароль неправельны!")

    return render_template("login.html")

@app.route('/register', methods=['GET', 'POST'])
def register():
    login = request.form.get("regName")
    password = request.form.get("regPassword")
    password_retype = request.form.get("passRepeat")

    if request.method == "POST":
        if not (login or password or password_retype):
            print("ERROR: Логин, пароль или его повторение неправельны!")
        elif password != password_retype:
            print("ERROR: Пароль и его повторение должны быть одинаковы!")
        else:
            hash_pwd = generate_password_hash(password)
            new_user = Users(login = login, password = hash_pwd)
            nexusdb.session.add(new_user)
            nexusdb.session.commit()

            return redirect(url_for('login')) # В url_for имя функции

    return render_template("register.html")

@app.route('/logout', methods=['GET', 'POST'])
@login_required
def logout():
    logout_user()
    return redirect("/")

@app.route('/boards/post/<int:postid>', methods=['GET', 'POST'])
@login_required
def post_detail(postid):
    if request.method == "POST":
        text = request.form.get("CommentText")
        user = current_user.login

        if text and user:
            comment = Comments(user_name = user, text=text, post_id = postid)

            nexusdb.session.add(comment)
            nexusdb.session.commit()
            return redirect(f"/boards/post/{postid}")

    post = Posts.query.filter_by(id = postid).one()
    comments = Comments.query.filter_by(post_id = post.id).all()
    return render_template("post-detail.html", post = post, coms = comments)

@app.errorhandler(401)
def login_regirect(p):
    return redirect("/login")

@app.before_request
def before_request():
    if request.full_path.startswith('/admin/'):
        if current_user.is_admin == "FALSE":
            abort(400, 'Отказанно в доступе...')

admin.add_view(ModelView(Users, nexusdb.session, name="Пользователи"))
admin.add_view(ModelView(Posts, nexusdb.session, name="Посты"))
admin.add_view(ModelView(Comments, nexusdb.session, name="Комментарии"))

Error Message

I get the following error when deploying to Vercel:

OSError: [Errno 30] Read-only file system: ‘/var/task/instance’

Error importing api/app.py:  
Traceback (most recent call last):  
File “/var/task/_vendor/vercel_runtime/vc_init.py”, line 303, in  
__vc_spec.loader.exec_module(__vc_module)  
File “<frozen importlib._bootstrap_external>”, line 999, in exec_module  
File “<frozen importlib._bootstrap>”, line 488, in _call_with_frames_removed  
File “/var/task/api/app.py”, line 16, in  
nexusdb = SQLAlchemy(app)  
^^^^^^^^^^^^^^^  
File “/var/task/_vendor/flask_sqlalchemy/extension.py”, line 278, in __init__  
self.init_app(app)  
File “/var/task/_vendor/flask_sqlalchemy/extension.py”, line 373, in init_app  
self._apply_driver_defaults(options, app)  
File “/var/task/_vendor/flask_sqlalchemy/extension.py”, line 627, in _apply_driver_defaults  
os.makedirs(app.instance_path, exist_ok=True)  
File “”, line 225, in makedirs  
OSError: [Errno 30] Read-only file system: ‘/var/task/instance’  
Python process exited with exit status: 1.

Help me pls

from flask import Flask, render_template, url_for from flask import request, flash, redirect, session, abort from flask_login import login_user, logout_user, login_required, current_user, UserMixin from werkzeug.security import check_password_hash, generate_password_hash from flask_sqlalchemy import SQLAlchemy from flask_admin import Admin from flask_admin.contrib.sqla import ModelView from flask_login import LoginManager, UserMixin import os app = Flask(__name__) app.config["SQLALCHEMY_DATABASE_URI"] = 'sqlite:///nexus.db' nexusdb = SQLAlchemy(app) lm = LoginManager(app) mem0_dir = os.environ.get("MEM0_DIR", "/tmp/.mem0") class Users (nexusdb.Model, UserMixin): __tablename__ = 'users' id = nexusdb.Column(nexusdb.Integer, primary_key=True) login = nexusdb.Column(nexusdb.String(128), nullable=False) password = nexusdb.Column(nexusdb.String(255), nullable=False) description = nexusdb.Column(nexusdb.String(255), default="Нет описания...") is_admin = nexusdb.Column(nexusdb.String(18), default="FALSE") class Posts (nexusdb.Model): __tablename__ = 'posts' id = nexusdb.Column(nexusdb.Integer, primary_key=True) user_name = nexusdb.Column(nexusdb.Integer, nexusdb.ForeignKey('users.id')) text = nexusdb.Column(nexusdb.Text, nullable=False) name = nexusdb.Column(nexusdb.String(64), nullable=False) board = nexusdb.Column(nexusdb.String(64), nullable=False) class Comments (nexusdb.Model): __tablename__ = 'comments' id = nexusdb.Column(nexusdb.Integer, primary_key=True) user_name = nexusdb.Column(nexusdb.Integer, nexusdb.ForeignKey('users.id')) post_id = nexusdb.Column(nexusdb.Integer, nexusdb.ForeignKey('posts.id')) text = nexusdb.Column(nexusdb.Text, nullable=False) def CREATE_ALL(): with app.app_context(): nexusdb.create_all() admin = Admin(app, name="Админ-панель") app.secret_key = "salty_web3418" @lm.user_loader def load_user(user_id): return Users.query.get(user_id) @app.route("/") def homeRedirect(): return redirect("/home") @app.route("/home") def home(): l = current_user.is_authenticated p = Posts.query.limit(3).all() return render_template("home.html", loginned=l, posts = p) @app.route("/boards") def boards(): l = current_user.is_authenticated return render_template("boards.html", loginned=l) @app.route("/boards/random", methods=['GET', 'POST']) @login_required def boards_random(): if request.method == "POST": postname = request.form.get("RandomPostName") posttext = request.form.get("RandomPostText") if not postname or not posttext: print("ERROR: Имя или текст поста неправельны!") post = Posts(name = postname, text = posttext, board = "random", user_name = current_user.login) nexusdb.session.add(post) nexusdb.session.commit() return redirect("/boards/random") else: posts = Posts.query.filter_by(board = "random").order_by(Posts.name).all() return render_template("random-b.html", posts = posts) @app.route("/boards/clean", methods=['GET', 'POST']) @login_required def boards_clean(): if request.method == "POST": postname = request.form.get("CleanPostName") posttext = request.form.get("CleanPostText") if not postname or not posttext: print("ERROR: Имя или текст поста неправельны!") post = Posts(name = postname, text = posttext, board = "clean", user_name = current_user.login) nexusdb.session.add(post) nexusdb.session.commit() return redirect("/boards/clean") else: posts = Posts.query.filter_by(board = "clean").order_by(Posts.name).all() return render_template("clean-b.html", posts = posts) @app.route("/boards/creative", methods=['GET', 'POST']) @login_required def boards_creative(): if request.method == "POST": postname = request.form.get("CreativePostName") posttext = request.form.get("CreativePostText") if not postname or not posttext: print("ERROR: Имя или текст поста неправельны!") post = Posts(name = postname, text = posttext, board = "creative", user_name = current_user.login) nexusdb.session.add(post) nexusdb.session.commit() return redirect("/boards/creative") else: posts = Posts.query.filter_by(board = "creative").order_by(Posts.name).all() return render_template("creative-b.html", posts = posts) @app.route("/user", methods=['GET', 'POST']) @login_required def user(): user = current_user if request.method == 'POST': newlogin = request.form.get("userName") newdes = request.form.get("userDes") user.login = newlogin user.description = newdes nexusdb.session.commit() newuser = current_user return render_template("user.html", u=newuser) return render_template("user.html", u=user) @app.route("/login", methods=['GET', 'POST']) def login(): login = request.form.get("loginName") password = request.form.get("loginPassword") if request.method == "POST": if login and password: user = Users.query.filter_by(login=login).first() if user and check_password_hash(user.password, password): login_user(user) return redirect("/home") else: print("ERROR: Логин или пароль неправельны!") else: print("ERROR: Логин и пароль неправельны!") return render_template("login.html") @app.route('/register', methods=['GET', 'POST']) def register(): login = request.form.get("regName") password = request.form.get("regPassword") password_retype = request.form.get("passRepeat") if request.method == "POST": if not (login or password or password_retype): print("ERROR: Логин, пароль или его повторение неправельны!") elif password != password_retype: print("ERROR: Пароль и его повторение должны быть одинаковы!") else: hash_pwd = generate_password_hash(password) new_user = Users(login = login, password = hash_pwd) nexusdb.session.add(new_user) nexusdb.session.commit() return redirect(url_for('login')) # В url_for имя функции return render_template("register.html") @app.route('/logout', methods=['GET', 'POST']) @login_required def logout(): logout_user() return redirect("/") @app.route('/boards/post/<int:postid>', methods=['GET', 'POST']) @login_required def post_detail(postid): if request.method == "POST": text = request.form.get("CommentText") user = current_user.login if text and user: comment = Comments(user_name = user, text=text, post_id = postid) nexusdb.session.add(comment) nexusdb.session.commit() return redirect(f"/boards/post/{postid}") post = Posts.query.filter_by(id = postid).one() comments = Comments.query.filter_by(post_id = post.id).all() return render_template("post-detail.html", post = post, coms = comments) @app.errorhandler(401) def login_regirect(p): return redirect("/login") @app.before_request def before_request(): if request.full_path.startswith('/admin/'): if current_user.is_admin == "FALSE": abort(400, 'Отказанно в доступе...') admin.add_view(ModelView(Users, nexusdb.session, name="Пользователи")) admin.add_view(ModelView(Posts, nexusdb.session, name="Посты")) admin.add_view(ModelView(Comments, nexusdb.session, name="Комментарии"))

Error importing api/app.py: Traceback (most recent call last): File “/var/task/_vendor/vercel_runtime/vc_init.py”, line 303, in __vc_spec.loader.exec_module(__vc_module) File “<frozen importlib._bootstrap_external>”, line 999, in exec_module File “<frozen importlib._bootstrap>”, line 488, in _call_with_frames_removed File “/var/task/api/app.py”, line 16, in nexusdb = SQLAlchemy(app) ^^^^^^^^^^^^^^^ File “/var/task/_vendor/flask_sqlalchemy/extension.py”, line 278, in __init__ self.init_app(app) File “/var/task/_vendor/flask_sqlalchemy/extension.py”, line 373, in init_app self._apply_driver_defaults(options, app) File “/var/task/_vendor/flask_sqlalchemy/extension.py”, line 627, in _apply_driver_defaults os.makedirs(app.instance_path, exist_ok=True) File “”, line 225, in makedirs OSError: [Errno 30] Read-only file system: ‘/var/task/instance’ Python process exited with exit status: 1.