postgres documentation lacks information on use with docker

[richvdh]

(see: https://github.com/matrix-org/synapse/blob/master/docs/postgres.md)

... in particular, it doesn't say how to run synapse_port_db

[richvdh]

For the record, I think you can do something like:

docker run --rm -it \
    --mount type=volume,src=synapse-data,dst=/data \
    --entrypoint /usr/local/bin/synapse_port_db \
    matrixdotorg/synapse:latest \
    --sqlite-database /data/homeserver.db.snapshot \
    --postgres-config /data/homeserver-postgres.yaml

[beda17]

For those using docker-compose:

docker-compose run --rm --entrypoint /usr/local/bin/synapse_port_db synapse --sqlite-database=/data/homeserver.db --postgres-config=/data/homeserver_new.yaml --curse

synapse ............................. your synapse container name
homeserver.db .................. your sqlite database file
homeserver_new.yaml ...... your new config file

Don't forget to start your postgresdb first and learn from my mistake: If you limit the postgresql container memory, give enough.

[richvdh]

@beda17 would you be able to open a PR to add this to the documentation?

[beda17]

I am not a programmer, but I am using git for few months and I would like to contribute. I will get my courage together and try to propose a PR.

[chmac]

Another option to run synapse_port_db is to remove the PORTS option in the docker compose file, thus taking the server offline, get a bash terminal like docker exec -it synapse_container_id /bin/bash and then run the script. Ugly, but it gets the job done.

[chmac]

I've submitted a PR which addresses some of these topics, links to this issue, and mentions in the example compose file that it's necessary to actually enable postgres in the config file, otherwise sqlite is the default.