docs(README): init with setup instructions

Signed-off-by: Francesco Noacco <[email protected]>

README.md

@@ -1,23 +1,98 @@
 <!---
-  Copyright 2023 SECO Mind Srl
+  Copyright 2023-2024 SECO Mind Srl
   SPDX-License-Identifier: Apache-2.0
 -->
 
-# EdgehogDeviceForwarder
+# Edgehog Device Forwarder
 
-To start your Phoenix server:
+Proxy server to facilitate communication with Edgehog devices.
+It handles HTTP messages and WebSocket connections between the device and the user client.
 
-  * Run `mix setup` to install and setup dependencies
-  * Start Phoenix endpoint with `mix phx.server` or inside IEx with `iex -S mix phx.server`
+It's only been tested with simple WebSocket connections such as
+[`ttyd`](https://github.com/tsl0922/ttyd), however it should handle arbitrary requests
+as long as you keep in mind its [limitations](#known-issues-and-limitations).
 
-Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.
+## Running the Forwarder locally
 
-Ready to run in production? Please [check our deployment guides](https://hexdocs.pm/phoenix/deployment.html).
+### Start the server
 
-## Learn more
+The first component to be available should be this server,
+as both the device and the client will connect to it.
 
-  * Official website: https://www.phoenixframework.org/
-  * Guides: https://hexdocs.pm/phoenix/overview.html
-  * Docs: https://hexdocs.pm/phoenix
-  * Forum: https://elixirforum.com/c/phoenix-forum
-  * Source: https://github.com/phoenixframework/phoenix
+#### Manual installation
+
+Run the following command to clone the current repository and navigate to it
+
+```bash
+git clone https://github.com/edgehog-device-manager/edgehog_device_forwarder && \
+cd edgehog_device_forwarder
+```
+
+This project requires **Elixir 1.15** with **OTP 26** to run.
+If you use [`asdf`](https://asdf-vm.com/) or [`nix`](https://nixos.org/), you may also use those
+to install the officially supported version.
+
+Now use the following command to start the server:
+
+```bash
+mix phx.server
+```
+
+### Connect a device
+
+You will now need to start the device process.
+You can do so from the same machine or another device or virtual machine.
+The process should be the same, however make sure port 4000 is allowed by the server's firewall.
+
+To connect to the server you will need to use the e2e-test-forwarder program, available in the
+[`edgehog-device-runtime`](https://github.com/edgehog-device-manager/edgehog-device-runtime)
+repository.
+
+#### Manual install
+
+> At the time of writing, you need to use a fork of said repository, because not all the code
+> has been merged.
+> Use the command
+>
+> ```bash
+> git clone https://github.com/rgallor/edgehog-device-runtime -b ws-over-ws && \
+> cd edgehog-device-runtime/e2e-test-forwarder
+> ```
+
+This is a Rust program, so to compile it you will need
+to install [`cargo`](https://www.rust-lang.org/tools/install). Then run it using
+
+```bash
+cargo run -- -H server.local -t abcd
+```
+
+In this example:
+
+- `abcd` is our connection token, which will be used later to connect to the device;
+- `server.local` is the server's host address,
+  so make sure to replace it with your actual server address.
+
+> You don't need to open any port on the device,
+> as all requests will be performed by the device itself.
+
+If you don't get any error from the `cargo run` command you should be connected!
+
+On the same machine, start a `ttyd` server:
+
+```bash
+ttyd -W bash
+```
+
+### User connection
+
+All that's left is to actually perform the http requests!
+
+From any device open a web browser and type in the url `http://server.local:4000/v1/abcd/http/7681`.
+You should see `ttyd`'s window in your browser!
+
+> As before, you should replace `server.local` and `abcd`
+> with your server's host address and your connection token respectively.
+
+## Known issues and limitations
+
+- [ ] maximum message size: 8MB