Korv is an API framework that uses TCP sockets over SSH to exchange JSON data with a REST-like protocol. It's built on top of the asyncssh module, so it uses asyncio to manage the sockets and its callbacks. This allows you to build rich APIs with the session security of SSH and without the TCP overhead of HTTP.

Communications over this framework requires SSH keys like logging into a normal SSH server:

• The server itself has a private key and a set of public keys for the authorized clients.
• The client has a private key and a set of public keys for the servers it can connect to.

Verbs

There are 4 main verbs that indicate the intent of your request:

• GET for retrieving information.
• STORE for creating new objects.
• UPDATE for changing existing objects.
• DELETE for removing objects.

Keys

As discussed previously, you establish an SSH session with the server, so it's possible to reuse existing keys or generate them through any standard mechanism like the one below:

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

Server

Getting a server up and running is very simple:

fromkorvimportKorvServerdefhello(request):
"""Callback for the /hello endpoint"""return200, {'msg': 'Hello World!'}
defecho(request):
"""Callback for the /echo endpoint"""return200, {'msg': f'{request}'}
# Create a serverk=KorvServer(host_keys=['PATH_TO_YOUR_SERVER_PRIVATE_KEY'], authorized_client_keys='PATH_TO_YOUR_AUTHORIZED_PUBLIC_KEYS')
# Register the callbacksk.add_callback('GET', '/hello', hello)
k.add_callback('GET', '/echo', echo)
# Start listening for requestsk.start()

This will start a new SSH server with the specified private key that listens on port 8022 by default and will accept the clients listed in the authorized keys.

Client

Following is an example on how to communicate with this server.

>>>fromkorvimportKorvClient>>>>>># Create the client>>>k=KorvClient(client_keys=['PATH_TO_YOUR_CLIENTS_PRIVATE_KEY'])
>>>>>># Issue a GET request and print the output>>>k.get('/hello', callback=lambdaresponse: print(response['body']))
>>> {'msg': 'Hello World!'}

Return Codes

We're using standard HTTP response codes:

• 200 = Success.
• 400 = Malformed request or missing parameters.
• 404 = NotFound
• 500 = Internal error.

Server exceptions map to a 500 return code ans will include a traceback in the response.