Remote Sessions

You can start interactive remote sessions on the Wasmer Edge.

A session opens an interactive bash shell, which allows you to run any package from the Wasmer registry.

You can even forward ports from the session to your local machine, allowing you access to servers running inside the session!

Note that at the moment sessions do not persist after the connection is closed. In the future persistent sessions will be introduced. This means you will be able to close the connection and then re-connect to your session later on, giving you a persistent remote environment.

While this isn't available quite yet, sessions are already useful to explore the ecosystem and to test out the behaviour of your own apps.

Usage

To start a session:

• Install the wasmer CLI and log in to Wasmer See the Quickstart for a guide.
• Make sure the ssh command is installed.

Once that is done, you can simply run:

$ wasmer ssh

This will drop you right into a interactive bash session. You can now use standard Linux commands like cd, ls, mkdir, etc.

You also have access to the wasmer run command, so you can run arbitrary packages from the Wasmer registry inside your ssh session.

For example:

$ wasmer run john-sharratt/catsay meow

To forward a port, run:

wasmer ssh --map-port 9000

This will forward your local port 9000 to port 9000 in the remote instance, allowing you to access remotely running servers.

Example: Local Access to a Remote Server

We can now combine all these features to run a static web server inside a remote session, and access the server locally through a forwarded port.

The below will first start a session with port 9000 mapped. We then create a public directory and a stub index.html file, and start a static web server on port 9000.

$ wasmer ssh --map-port 9000
 
> mkdir public
> echo HELLO > public/index.html
> wasmer run wasmer/static-web-server -- -p 9000

You will now be able to access the remote server!

Run this on your local machine in a new terminal window:

$ curl localhost:9000
 
> HELLO

How It Works

wasmer ssh simply connects to a server in the Wasmer Edge network through a standard SSH connection.

The server then runs a command (bash by default), and connects stdin, stdout and stderr of the running workload with the SSH session, forwarding all input and output.

Port forwarding is also achieved through SSH.

In fact, you could simply replace wasmer ssh with ssh token@WASMER-SERVER-IP.

The only thing special about wasmer ssh is that it will automatically provision a token for your user that will be recognized by the Edge servers.

Billing

Remote sessions will count toward your resource usage on Wasmer, and will be included in your invoice.