500 OOPS: vsftpd: refusing to run with writable root inside chroot()

500 OOPS: vsftpd: refusing to run with writable root inside chroot()

Error:
[root@dockerserver log]# ftp 0
Connected to 0 (0.0.0.0).
220 (vsFTPd 3.0.2)
Name (0:root): ftpuser
331 Please specify the password.
Password:
500 OOPS: vsftpd: refusing to run with writable root inside chroot()
Login failed.
421 Service not available, remote server has closed connection

This Error may hit you when you have installed vsftpd and trying to ftp to it. 
This happens because we are using chroot, which want to us that user should not have write access to the top level directory within the chroot.
To solve the issue add following line to /etc/vsftpd/vsftpd.conf.
allow_writeable_chroot=YES
After saving the changes , restart the vsftpd service.

[root@dockerserver log]# service vsftpd restart
Redirecting to /bin/systemctl restart vsftpd.service

Now test the Ftp Connection.
[root@dockerserver log]# ftp 0
Connected to 0 (0.0.0.0).
220 (vsFTPd 3.0.2)
Name (0:root): ftpuser
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp>