Architecture

The overall system comprises a series of services, background queues and third-party backing services, as shown in the diagram below:

All the services and background queues provided by this Internet gateway run on Node.js and share a common Docker image.

Services

This app implements the minimum set of services required for an Awala Internet gateway:

PoWeb server

A PoWeb server, to exchange parcels with private gateways via the Internet.

This server is powered by Fastify and ws.

CogRPC server

A CogRPC server, to exchange parcels with private gateways via an end-to-end encrypted sneakernet.

An operator may choose not to deploy the CogRPC server if their users don’t need the ability to use the sneakernet.

This server is powered by grpc.

PoHTTP server

A PoHTTP server, to receive parcels from other gateways or public endpoints.

This server is powered by Fastify.

Background queues

For performance, scalability and reliability reasons, the services above defer computationally- or IO-intensive operations to background queues:

Cargo Relay Connection (CRC) queue

The CRC queue decrypts and processes the contents of each cargo stored by the CogRPC service.

Parcel Delivery Connection (PDC), Internet-bound queue

This queue delivers each parcel stored by the CogRPC and PoWeb services. This client uses @relaycorp/relaynet-pohttp.

Backing services

The components provided by this Internet gateway employ the following third-party backing services:

S3-compatible, object store server

This server is used to store parcels bound for private gateways. Minio is used in development.

CloudEvents broker

Any CloudEvents supported by @relaycorp/cloudevents-transport.

Redis

Redis PubSub is used for inter-component communication using asynchronous messaging, when we don’t need messages to be persisted. The following channels are used:

• pdc-parcel.${privateGatewayId} where ${privateGatewayId} is the id of the private gateway. Parcels received via Internet-based PDCs (e.g., PoHTTP) are published on these channels.

Key Management Service (KMS)

Any KMS supported by @relaycorp/webcrypto-kms documentation.

MongoDB

MongoDB is used to store the certificates owned by the Internet gateway instance, as well as transient metadata about private gateways (e.g., DH public keys, outgoing parcels).

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