42 lines
1.3 KiB
ReStructuredText
42 lines
1.3 KiB
ReStructuredText
Request Life Cycle
|
|
==================
|
|
|
|
This section describes the sequence of events happening for each request
|
|
answered by the User HTTP Interface.
|
|
|
|
.. image:: ../_static/request_life_cycle.png
|
|
|
|
|
|
1. The user makes a request to the User HTTP 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. ``kapow`` spawns the binary specified as entrypoint in the matching route
|
|
|
|
The default entrypoint is /bin/sh; we'll explain this workflow for now.
|
|
|
|
The spawned entrypoint is run with the following variables added to its
|
|
environment:
|
|
|
|
- ``KAPOW_HANDLER_ID``: Containing the `HANDLER_ID`
|
|
- ``KAPOW_DATAAPI_URL``: With the URL of the `data interface`
|
|
- ``KAPOW_CONTROLAPI_URL``: With the URL of the `control interface`
|
|
|
|
3. 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.
|
|
|
|
4. The shell dies
|
|
5. ``kapow`` finalizes the original request
|
|
|
|
|
|
.. todo::
|
|
|
|
link to resource tree
|