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ao Unit Router

The ao Unit Router is a simple Reverse Proxying Service, used to facilitate and simulate a distributed ao Network. It is implemented as a simple NodeJS Service, using the popular, robust, and lightweight http-proxy to manage Reverse Proxied Requests to the underlying host.

This service will deterministically route ao Process operations to an underlying host. In other words, a Process will always be routed to the same underlying ao Unit, according to it's index in the HOSTS environment variable. If, for whatever reason, the underlying host cannot be reached, the ao Unit Router will determinstically, and transparently, failover to the next underyling host. If all underlying hosts cannot be reached, the final err is returned in the response to the client.

• Usage
• Environment Variables
• Tests
• Debug Logging
• Project Structure
• System Requirements

Usage

First install dependencies using npm i.

Then simply start the server using npm start or npm run dev if you are working on the project locally. This will start a hot-reload process listening on port 3005 by default.

Environment Variables

There are a few environment variables that you MUST set:

• NODE_CONFIG_ENV: whether the service should be ran in development or production mode. Basically, this loads a separate set of default configuration.
• AO_UNIT: which ao Unit, either cu or mu, this Reverse Proxy Service is meant to mirror.
• HOSTS: a comma-delimited string containing all of the underlying hosts that can Reverse Proxied to. If AO_UNIT is cu, then HOSTS should be a series of ao Compute Unit Hosts. Similarly if AO_UNIT is mu then HOSTS should be a series of ao Messenger Unit Hosts
• STRATEGY: either redirect or proxy (default). If STRATEGY is redirect, the service will reply with an HTTP 307 Temporary Redirect to the underlying ao unit. If STRATEGY is proxy, the service will act as a reverse proxy to the underlying ao unit and forward the HTTP request itself.

The below environment variables are optional. All 3 must be set for subrouting to work.

• SUBROUTER_URL the underlying router to route to
• SUR_URL the SU-R url to use to check process owners for subrouter redirection
• OWNERS a list of owners to redirect to a subrouter

In order for the Router's Reverse Proxying to be consistent, the ordering of the HOST list MUST be consistent.

Tests

You can execute unit tests by running npm test

Debug Logging

You can enable verbose debug logging on the Web Server, by setting the DEBUG environment variable to the scope of logs you're interested in

All logging is scoped under the name ao-router*.

Project Structure

This ao Unit Router project is simple service, with minimal business logic.

System Requirements

The ao Unit Router Server is containerized stateless application, and can be deployed to any containerized environment using its Dockerfile. It will also need some way to receive secrets injected from it's environment ie. some sort of Parameter Store. See Environment Variables.

It will need to accept ingress from the Internet over HTTPS in order to fulfill incoming requests, and egress to other ao Units over HTTP or HTTPS.

So in summary, this ao Unit Server system requirements are:

• a Containerization Environment to run the application
• Memory scaling
• an ability for secrets to be Injected into the Environment
• an ability to accept Ingress from the Internet
• an ability to Egress to other ao Units