Request Life Cycle

This section describes the sequence of events happening for each request answered by the HTTP User Interface.

1. request

The user makes a request to the HTTP User Interface.

• The request is matched against the route table.
• kapow provides a HANDLER_ID to identify this request and don’t mix it with other requests that could be running concurrently.

2. spawn

kapow spawns the executable specified as entrypoint in the matching route.

The default entrypoint is /bin/sh; let’s focus on this workflow.

The spawned entrypoint is run with the following variables added to its environment:

• KAPOW_HANDLER_ID: Containing the HANDLER_ID
• KAPOW_DATA_URL: With the URL of the HTTP Data Interface
• KAPOW_CONTROL_URL: With the URL of the HTTPS Control Interface

3. kapow set /response/body banana

During the lifetime of the shell, the request and response resources are available via these commands:

• kapow get /request/...
• kapow set /response/...

These commands use the aforementioned environment variables to read data from the user request and to write the response. They accept data either as arguments or from stdin.

4. exit

The shell dies. Long live the shell!

5. response

kapow finalizes the original request. Enjoy your banana now.