websocket-proxy

This package provides a websocket proxy that allows you to overcome networking difficulties when connecting services running in isolated networks to a cloud.

It does that by providing a websocket channel that proxies local port to the remote server.

Installation

# install node and npm
sudo apt install nodejs npm  # it's roughly 50MB :(

# clone the repository
git clone https://github.com/fragaria/websocket-proxy.git
cd websocket-proxy

# install dependencies
npm install

Running a server

This will make isolated services available in the cloud.

node run server

By default, server launches on port 8090.

Server accepts these environamental variables:

• ADDRESS ... TCP/IP address to listen on (default: localhost)
• PORT: ... TCP/IP port number to bind to (default: 8090)
• KEY_SERVER_URL ... URL to a key server. When set, WS Server will call GET request on ``<KEY_SERVER_URL>/key/"```. If the othe party responds with other status code than 200, the connecting client is immediatelly disconnected. If KEY_SERVER_URL is undefined, client with any key can connect (default: undefined).

Configuration environment variables

Client and Server can be configured through environment variables. Forexample run KEY=1234 npm run client to start client with client key 1234. Here is a list of supported configuration variables.

Server

• ADDRESS - the address to listen on (default: localhost)
• PORT - port to listen on (default: 8090)
• KEY_SERVER_URL - key-mster API url for authentication or empty to ignore authentication (default: none)
• KEY_SERVER_IGNORE_FOR_HOSTNAMES - hostnames to be ignored for key server (default: none)
• CLIENT_INACTIVE_AFTER_SECS - number of seconds of client inactivity after which the connection is considered dead (default: 90),
• SERVER_CLIENT_LIST_DUMP_FILE - filepath where to keep list of connected clients; If empty, no list is being written (default: none)

Client

• KEY - client key (default: client-1
• SERVER_URL - url of Websocket Proxy server (default: ws://localhost:8090),
• FORWARD_TO - url where to forward all communication to (default: http://prusa3d.local),
• FORWARD_TO_PORTS - comma separated list of ports where to forward communication to (default: 80,443)

Connecting a client to the server

Using websocket-proxy client, you can connect your service in your isolated network to the cloud-hosted websocket-proxy server.

Assuming you have a running server on http://ws.yourdomain.com, you can expose your local port 80 like this:

# Connect local port to the cloud-hosted proxy server
client_key=myclient-1
node client $client_key http://ws.yourdomain.com http://localhost:80

# Test your local port is available
curl http://ws.yourdomain.com/api/$client_key/

Note the trailing slash: it has to be present!

Creating websocket_proxy.server as docker image

# Clone this
git clone https://github.com/fragaria/websocket-proxy.git
cd websocket-proxy

# Build docker image
docker build -t fragaria/websocket-proxy:latest .

# Start docker container
docker create -p 127.0.0.1:8090:8090 --name websocket-proxy fragaria/websocket-proxy:latest
docker start websocket-proxy

# Test connecting a client
node client random-client-id http://localhost:8090 http://weevil.info/

Now open your browser and paste url: http://localhost:8090/api/random-client-id/ and voilà, what a nice bug you see.

Installing client as a systemd service

Install the application to a well known location:

git clone https://github.com/fragaria/websocket-proxy.git
sudo cp -ax websocket-proxy /opt/websocket-proxy
sudo mv /opt/websocket-proxy.service /etc/systemd/system
sudo mv /opt/websocket_proxy.conf /etc

Now modify /etc/websocket_proxy.conf accoring to your needs. Finally, enable the installed service:

sudo systemctl daemon-reload
sudo systemctl enable websocket-proxy

Running tests

npm test