Upgrading from Stretch to Buster with docker 3rd party installed

Hi,

I was going to upgrade to Buster, but I've got docker installed and am running a container as an ldap server. Consequently I don't want to get rid of it, but the install guide I read suggested removing all 3rd-party repositories before starting.

This is the current situatioin with my sources files
❱ cat /etc/apt/sources.list
#

# deb cdrom:[Debian GNU/Linux 9.0.0 _Stretch_ - Official amd64 NETINST 20170617-13:06]/ stretch main

#deb cdrom:[Debian GNU/Linux 9.0.0 _Stretch_ - Official amd64 NETINST 20170617-13:06]/ stretch main

deb http://ftp.uk.debian.org/debian/ stretch main contrib non-free
deb-src http://ftp.uk.debian.org/debian/ stretch main contrib non-free

deb http://security.debian.org/debian-security stretch/updates main
deb-src http://security.debian.org/debian-security stretch/updates main

# stretch-updates, previously known as 'volatile'
deb http://ftp.uk.debian.org/debian/ stretch-updates main
deb-src http://ftp.uk.debian.org/debian/ stretch-updates main

❱ cat /etc/apt/sources.list.d/docker.list
deb https://download.docker.com/linux/debian stretch stable

If anyone has any advice, please let me know,

Thanks