Backend

This is a collection of services comprising the UWFlow backend.

Architecture

The architecture is explained in a standalone RFC.

Requirements

The following packages are required for core functionality:

• docker
• docker-compose

The following packages are required by optional components:

• hasura-cli: Hasura web interface

Exact package names may vary across distributions; for example, Ubuntu refers to docker as docker.io. The above list is intended as an unambiguous guideline for humans and is not necessarily consistent with any single distribution.

First-time setup

To find out what is really expected, peruse scripts/sanity-check.sh and apply common sense, as the following docs may be outdated.

1. Ensure the required packages are installed (see above).
2. Download and decrypt the database dump:

• Download the file located in Google Drive at Flow/Data/pg_backup.gpg.
• Run gpg2 --decrypt pg_backup.gpg > pg_backup. Use the password from the shared Bitwarden vault.

3. Copy .env.sample to .env and edit the latter as needed. In particular:

• POSTGRES_DUMP_PATH should point to pg_backup obtained at the end of (2)
• UW_API_KEY_V3 should be set as instructed in the uwapi-importer README
• POSTGRES_HOST should be set to postgres on *NIX systems and 0.0.0.0 on Windows (which is incidentally otherwise unsupported)

How to run this

If you have not run the backend before, refer to the preceding section first. That being done, simply run script/start.sh.

As dependencies between containers exist that cannot be explicitly specified, the system will take a while to reach a stable (all services up) state. The script will wait as this happens, but it should not take more than a minute. If it does, then something went wrong. Ping #backend-dev.

It is instructive to study the script, as it often does not need to be re-run in its entirety. For example, when developing api, it is not necessary clear database state, so the following command suffices:

docker-compose up -d --build

Interacting with the backend

When docker-compose is active, services may be accessed at their published ports, as declared in docker-compose.yml.

To illustrate, the postgres service publishes port 5432, so

psql -h localhost -p 5432 -U flow

will spawn a Postgres shell connected to the database container. If you do not happen to have postgres-client installed, this also works:

$ docker exec -it postgres sh
(docker) # psql -U postgres flow