Sinfonia

Manages discovery of nearby cloudlets and deployment of backends for edge-native applications.

Tier 1 is located in the cloud and it tracks availability of Tier 2 instances at various cloudlets where backends can be deployed. Tier 3 is the client application that mediates the discovery and deployment process for edge-native applications.

This repository implements an example Tier3 client which can be used both as a command-line application, and as a Python library.

Installation

This should be installable with pip install sinfonia-tier3.

Usage

The sinfonia-tier3 application would normally be called by an edge-native application to start an application specific backend on a nearby cloudlet.

The information normally provided by the app are the URL of a Tier1 instance and the UUID identifying the needed backend. Finally the actual frontend application and arguments that will be launched once the backend deployment has started.

$ sinfonia-tier3 <tier1-url> <uuid> <frontend-app> <args...>

An example application with UUID:00000000-0000-0000-0000-000000000000 (or the convenient alias 'helloworld') starts an nginx server that will be accessible with the hostname 'helloworld'.

$ sinfonia-tier3 https://tier1.server.url/ helloworld /bin/sh
sinfonia$ curl -v http://helloworld/
...
sinfonia$ exit

When the frontend application exits, the network namespace and wireguard tunnel are cleaned up. Any resources on the cloudlet are automatically released once Tier2 notices the VPN tunnel has gone idle for some time

Installation from this source repository

You need a recent version of poetry

$ pip install --user pipx
$ ~/.local/bin/pipx ensurepath
... possibly restart shell to pick up the right PATH
$ pipx install poetry

And then use poetry to install the necessary dependencies,

$ git clone https://github.com/cmusatyalab/sinfonia-tier3.git
$ cd sinfonia-tier3
$ poetry install
$ poetry run sinfonia-tier3 ...
... or
$ poetry shell
(env)$ sinfonia-tier3 ...

Why does we need a sudo password when deploying

We need root access to create and configure a Wireguard tunnel endpoint that connects the local application's network namespace/container to the deployed backend. All of the code running as root is contained in src/sinfonia_tier3/root_helper.py

Right now it runs the equivalent of,

ip link add wg-tunnel type wireguard
wg set wg-tunnel private-key <private-key> peer <public-key> endpoint ...
ip link set dev wg-tunnel netns <application network namespace>