November-2022-Upgrade missing docker-compose file

Hi Guys,
I am currently (trying to) migrating PostgreSQL and MongoDB. I already failed on step one since i cannot find the right file “docker-compose.primary.backend.template.yml”. It simply doesnt exist in our clients env.

After a long search i pulled the newest branch in hopes this will work, it didnt. Could somebody please lead me on the right path?

Regards,
Level-1 IT Support with no clue.

Welcome to the community, @MrRaypizar! Pinging @stephenoduor and @ks_1 for your support.

Update:
I followed the steps in the migration guide and configured the file docker-compose.backend.primary.override.yml. Everything worked fine until Step 8, where I’m required to upgrade PostgreSQL 9.5. Since PostgreSQL 9.5 has reached EOL, I am unable to find the necessary packages via apt-get, which halts my progress.

Below is the output of my attempt:

root@postgres:/# apt-cache policy postgresql-9.5-postgis-3 && \
    POSTGIS_VERSION_9_5=$(apt-cache policy postgresql-9.5-postgis-3|grep Candidate:|awk '{print $2}') && \
    apt-get install -y --no-install-recommends postgresql-9.5-postgis-3=${POSTGIS_VERSION_9_5} postgresql-9.5-postgis-3-scripts=${POSTGIS_VERSION_9_5} && \
    apt-get upgrade
N: Unable to locate package postgresql-9.5-postgis-3
N: Couldn't find any package by glob 'postgresql-9.5-postgis-3'
N: Couldn't find any package by regex 'postgresql-9.5-postgis-3'
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
E: Unable to locate package postgresql-9.5-postgis-3
E: Couldn't find any package by glob 'postgresql-9.5-postgis-3'
E: Couldn't find any package by regex 'postgresql-9.5-postgis-3'
E: Unable to locate package postgresql-9.5-postgis-3-scripts
E: Couldn't find any package by glob 'postgresql-9.5-postgis-3-scripts'
E: Couldn't find any package by regex 'postgresql-9.5-postgis-3-scripts'

Can you advise on how to proceed with upgrading or migrating from PostgreSQL 9.5 given the lack of available packages?