backend

Beep backend, consisting of several microservices behind traefik, which provides CORS, SSL and authentication services, and orchestrated with docker. The name of each microservice is derived from its folder name. For example, the name of the microservice in backend-auth is auth. As always, more information, such as API docs, can be found in the individual READMEs of each service.

Quickstart

Requires docker-compose.

git clone git@makerforce.io:beep/backend.git
git submodule update --init --recursive
docker-compose up --build

Testing

Each microservice should have it's own integration and unit tests. Running integration tests should involve the following steps:

docker-compose -f docker-compose.integration.yml up
go test -tags=integration

Unit tests are easier:

go test -tags=unit

Background services

The microservices of Beep rely on a few background services, listed below. All of them are covered by the docker-compose file, but in case one wishes to run a service separately, they need to be provided. What a service needs is mentioned in its description.

Name	Website
postgres	[https://www.postgresql.org/]
redis	[https://redis.io/]
nats	[https://nats.io/]
minio	[https://min.io]

Services

The microservices of the Beep backend can be grouped into groups which each cover one of a few different areas of functionality, described below:

Auth

auth and login handle the authentication of user requests, coupled closely with traefik.

login

URL: <base-url>:1837

login takes a phone number and client id and then does a SMS OTP verification of the phone number. Client ID can be any value, but it is highly recommended that it be a unique value, like a MAC address or UUID. If verification succeeds, a signed JWT of the user id and client id is issued. This token will be used by the client for all future attempts of authentication.

login relies on a running redis instance.

auth

auth is completely invisible to the client. When traefik processes a request with a method other than OPTIONS, it calls auth, which parses the Authorization header looking for bearer authentication. If such a header is found, the token is retrieved and its signature verified. If all this succeeds, the request is allowed through with the X-User-Claim header populated by the token's contents. Otherwise, an error is returned and traefik rejects the request.

auth does not rely on anything, but is a bit pointless without a traefik instance calling on it.

Core

URL: <base-url>/core

core handles the retrieval and updating of the information that is not updated comparatively often. For example: user, conversation or contact data. Call this service to do things related to such information. It relies on the X-User-Claim header being populated by auth, mentioned previously. If you run this service without putting it behind a traefik router calling auth, then any old person can populate that header and claim to be anyone. I hope I don't need to say why that is insecure.

core relies on a running postgres instance. Is insecure if not behind traefik calling auth.

Heartbeat

URL: <base-url>/heartbeat

heartbeat handles "last seen" timings for users. A user pings the server periodically via a specific endpoint, which then caches the time of the ping while also updating subscribed clients. Clients subscribe through an EventSource endpoint. On first subscribe, the last cached time of the user in question is pushed to the EventSource stream.

heartbeat relies on a running redis instance. Is insecure if not behind traefik calling auth.

Pictures

URL: <base-url>/pictures

pictures is a simple file upload server whose intended function is to just be a place to park user and group profile pictures.

pictures relies on a running minio instance. Is insecure if not behind traefik calling auth.

Permissions

permissions is an internal system meant to check a user's permission to access something. Currently uses a user-scope system, i.e. user-conversation. Since most things in the backend are related to conversations, the working basis of the permissions model is that if a user is in a conversation, they are pretty much good to go. Caches permissions in redis in a misguided attempt at reducing latency.

permissions relies on a running redis instance.

Bite pipeline

Audio data in Beep is stored in discrete packets called "bites". The Bite pipeline takes in bites and processes them, doing things like storage and transcription to text. Currently, in an downright terrible implementation, bites are just discrete 1400 byte chunks separated with absolutely no regard whatsoever to their content.

webrtc

URL: <base-url>/webrtc

webrtc is a WebRTC Selective Forwarding Unit (SFU) router, keeping track of which conversation a user is in and routing based on that. At the same time, it also diverts the bites to the bite pipeline and issues a store request to store at the same time.

webrtc relies on a running nats instance. Is insecure if not behind traefik calling auth.

store

URL: <base-url/store

store is a wrapper around badger. Receives data through nats, generating keys based on a label supplied with the data. Also supports retrieval of specific data based on key, and scanning a range of keys based on timestamp and supporting retrieval via HTTP endpoints.

store relies on a running nats instance. Is insecure if not behind traefik calling auth.

transcription

transcription takes the raw audio data, packages it and then sends it to the Google Cloud Speech-to-Text. Sends the transcripted result to store to be stored.

transcription relies on a running nats instance. Is insecure if not behind traefik calling auth.

Staging