How to recover data in server terminal after error with odk central server in digital ocean

1. What is the issue? Please be detailed.
After almost 2years without issues I got an 504 error with the server. So I did sudo reboot.

root@docker-ubuntu-s-1vcpu-1gb-intel-ams3-01:~/central# docker --version && docker-compose version
Docker version 20.10.7, build f0df350
docker-compose version 1.29.2, build 5becea4c
docker-py version: 5.0.0
CPython version: 3.7.10
OpenSSL version: OpenSSL 1.1.0l 10 Sep 2019

2. What steps can we take to reproduce this issue?
Later, I tried to restart the server following upgrade instructions but I got an error:
COPY failed: file not found in build context or excluded by .dockerignore: stat files/allow-postgres14-upgrade: file does not exist
ERROR: Service 'postgres' failed to build : Build failed

First, I am interested in recovering the data from the terminal?
Second, if possible how can I recover the system and have odk central running again?

Thanks a lot,

It looks like you're on DigitalOcean? The easiest option is to restore from a backup/snapshot.

If you don't have a backup, fixing the upgrade is likely the best choice.

In this case, it seems you haven't followed the upgrade instructions because you are running an old version of Docker, but are trying to upgrade to the latest version of Central. Start by reviewing upgrade notes for all versions between your current version and the one you are upgrading to.

Hi Yaw,
I managed to upgrade docker, docker compose and postgres by following upgrade instructions. Thank you!