CODEWITHSUNDEEP
pythonapacheubuntuflaskmod-wsgi
Man8Blue
Man8Blue

Reputation: 1197

OperationalError: attempt to write a readonly database in ubuntu server

I'm running a FlaskApp using mod_wsgi and apache2 on Ubuntu server. I tried running the flask app on localhost successfully and then deployed it on ubuntu server.

But when i try to update database, its giving error:

Failed to update model. (OperationalError) attempt to write a readonly database u'UPDATE mysongs SET songurl=? WHERE songid.id = ?' (u'www.site.com/I_wanna_dance', 1)

Now i tried look for database file permission which is:

-rwxr-xr-x 1 www-data www-data 10240 Jul 14 15:35 /var/www/mywebsite/appfolder/appdata.db`

When i try changing permission to 777, 755, 644 etc. it shows another error: unable to open database file Although database file works fine with 644 permission on localhost but not on ubuntu server.

Also i checked permission of directories and for /var /var/www /var/www/mywebsite /var/www/mywebsite/appfolder etc., all have www-data:www-data as its owner username and group.

I tried googling and but no proper solution other than suggestion of changing file/dir permissions, which i have tried myself.

Why can't it read/access the database file?

Please suggest.

Upvotes: 9

Views: 20091

Answers (4)

Diego Bianchi
Diego Bianchi

Reputation: 742

Just give www-data permision to your project and db

sudo chown www-data:www-data ProjectPath

sudo chown www-data:www-data dbPath

Upvotes: 2

Yash Yennam
Yash Yennam

Reputation: 51

Faced this issue while hosting Django Rest Framework on IIS 7.5 / Windows 2008 Server. It was working fine on local host . I added new feature to handle file upload feature along with "file name" . The files were uploaded properly but the database seemed to not accept the text from "file name" string.

Solution : Go to your concern database. (if you have not assigned any particular database,consider the file db.sqlite3 in base folder)

Right click on the db.sqlite3 --> Properties --> Security --> Edit --> Add

In the text box enter Everyone --> Checkname --> ok

Refresh the server at IIS and try to run the application.

Upvotes: -1

PRMoureu
PRMoureu

Reputation: 13337

This issue is related to the files permissions management AND mostly to the user chosen in the Apache configuration file (*.conf) defined to holds the application processes. In a few words : the write permissions need to match this user.

Most of the time, the sqlite database file has been created by a specific user (for example your current user) and the site application is running under child processes launched by the Apache default user www-data (if the parameter user wasn't specified inside the directive WSGIDaemonProcess). In this case, the database can be read but it will throw this error if you try to modify anything :

(OperationalError) attempt to write a readonly database...

because www-data has no permission on the file (or on the parent folder)

First way : Apply permissions to the user www-data

You can set the write permissions on the database file and its parent folder.

If the folder contains other files, you can add write permission on it and only change the ownership of the database file to the user www-data, for example :

sudo chmod o+w db_directory
sudo chown www-data:  db_directory/site_database.db

Or if the folder contains only the database file, you can try to change the folder owner directly :

sudo chown -R www-data: db_directory

Then check that read/write permissions are well set (with ls -l site_database.db)

More help in this post.

Other solution : Add a specific user to hold the application processes

This can be done by giving the user and group parameters in the directive WSGIDaemonProcess in Apache configuration. It will make Apache launch the child processes under a specific user.

For example :

...
WSGIDaemonProcess main user=myuser group=myuser threads=3 python-home=/path/to/the/virtualenv/
WSGIProcessGroup main
WSGIApplicationGroup %{GLOBAL}
...

This user will manage all operation, including read/write to any files, so check that it has all needed permissions on every related files.

For security concerns, you may not use a wide-privileged user.

Some comments can help in this post.

Note : be careful if you manage your own logging files with directives like ErrorLog in the Apache configuration, these files will follow the same logic of permissions. The same for any file that could be changed by the application.

Upvotes: 9

Man8Blue
Man8Blue

Reputation: 1197

Resolved the issue. It was due to database file permission conflict.

Upvotes: 2

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