# Pirate PostgreSQL backup script

Pirate PostgreSQL backup script written in Python.

This script backs up an entire PostgreSQL database to a remote server using scp. Backup files are
compressed and labeled with a precise timestamp.

Configuration is taken from environment variables.

## Dependencies

- PostgreSQL
- Python 3.9+

## Configuration environment variables

| Name               | Purpose                                                                                                             |
| ------------------ | ------------------------------------------------------------------------------------------------------------------- |
| **PG_DUMPALL_CMD** | Full path to the `pg_dumpall` command included with the PostgreSQL installation. Defaults to `/usr/bin/pg_dumpall`. |
| **DATABASE_HOST**  | Database server host or socket directory. Defaults to `localhost`.                                                  |
| **DATABASE_PORT**  | Database server port number. Defaults to `5432`.                                                                    |
| **DATABASE_USER**  | Connect as specified database user. Defaults to `postgres`.                                                         |
| **SSH_HOST**       | Scp connect string. E.g. `user@host:/some/path/`                                                                    |

## Usage example

```sh
SSH_HOST="user@host:~/pirate-backup-directory/" /usr/bin/python3 pirate-backup.py
```

## Notes

- This script relies on [Trust Authentication](https://www.postgresql.org/docs/current/auth-trust.html) of the backup user on the local server and therefore does not support passing a password through an environment variable. This is usually sufficient for local connections, although peer authentication is often times recommended.

- This script relies on a working ssh connection for the local user to the remote machine using a public-private key pair. See [How To Configure SSH Key-Based Authentication on a Linux Server](https://www.digitalocean.com/community/tutorials/how-to-configure-ssh-key-based-authentication-on-a-linux-server) for instructions.