Key Concepts

Before you implement Tunneling to your functions, there are a few key concepts you need to familiarize yourself with:

• Third-party Reverse Proxy Service: Reverse-proxy providers will generate publicly accessible URLs upon your request that will proxy all requests to your local webserver, and will allow you to connect your localhost with the internet. You can choose any reverse-proxy provider of your choice. In this section of the help documentation, we will be going over detailed steps on generating Tunneling URL for your functions with the following reverse-proxy providers:
  • Ngrok
  • Localtunnel
  • Serveo
  • Localhost.run
  • Pagekite

• Tunneling URL: This is a URL generated by a reverse-proxy provider. This URL routes all the calls made to your non-HTTPS functions and Integration function to your local system. The local websever handles the application’s hosting which can be accessed with this URL. Essentially, this URL allows your local system to act as the server on which your Cron, Event and Integration functions can be executed. If your reverse-proxy provider does not generate the Tunneling URL properly, the Execution History of the function will be listed in the “URL Not Found” status when it is tunneled, and you will encounter an error.

• Tunneled Functions: These are non-HTTPS and Integration functions that you have selected to tunnel. Cron, Event and Integration functions are triggered only during runtime as a backend process and they typically are executed in the Catalyst cloud. However, when these functions are tunneled, their executions are routed to your local system. As a result, the live logs of these function executions will only be available in the CLI and not in the Catalyst Logs component, or anywhere in the console. The only other set of logs that will contain any information about Tunneling is the Audit Logs, where information such as when and by whom the tunneling was enabled will be displayed.

• Catalyst Function Shell: Catalyst allows you to launch a function shell in the Catalyst CLI, where you can debug functions. It functions much like a Node shell, but it is powered by the functionalities of Catalyst CLI. We will be using this shell to execute the Tunneling commands. You can find a list of the Catalyst shell commands for Tunneling in this section.

• Conditions to enable Tunneling: Tunneling is only possible in the development environment of Catalyst. To tunnel your functions, you must first make them available in the Catalyst console by either creating and coding them in the console from the Catalyst Serverless section, or by deploying them to the console after coding them in your local environment.

• Application Performance Monitoring will not be available for functions while they are being tunneled: When a function is being tunneled, calls made to the function are routed to your local system. This prevents the Application Performance Monitoring (APM) component from monitoring the performance of your function. However, if you terminate tunneling, then you can use APM to monitor the performance of the function.