This is part of a series of posts on backing up and restoring a backup for Matrix Synapse server. Synapse was installed using the matrix-docker-ansible deployment which while a little complicated can greatly ease management later on down the road. All the main components are in docker containers so we need to use docker to access.

https://github.com/spantaleev/matrix-docker-ansible-deploy/blob/master/docs/maintenance-postgres.md#backing-up-postgresql

As the root user run

docker exec --env-file=/matrix/postgres/env-postgres-psql matrix-postgres pg_dumpall -h matrix-postgres | gzip -c > /matrix/postgres.sql.gz

This will dump the Postgres database in /matrix/postgres.sql.gz
We can use this later to restore to a new server or keep as a backup.