63 lines
1.4 KiB
ReStructuredText
63 lines
1.4 KiB
ReStructuredText
Request Life Cycle
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==================
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This section describes the sequence of events happening for each request
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answered by the `User HTTP Interface`.
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.. image:: ../_static/request_life_cycle.png
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1. request
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----------
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The user makes a request to the `User HTTP Interface`.
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- The request is matched against the route table
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- ``kapow`` provides a `HANDLER_ID` to identify this request and don't mix it
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with other requests that could be running concurrently.
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2. spawn
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--------
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``kapow`` spawns the executable specified as entrypoint in the matching
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route.
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The default entrypoint is ``/bin/sh``; we'll explain this workflow for now.
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The spawned entrypoint is run with the following variables added to its
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environment:
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- ``KAPOW_HANDLER_ID``: Containing the `HANDLER_ID`
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- ``KAPOW_DATAAPI_URL``: With the URL of the `Data HTTP Interface`
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- ``KAPOW_CONTROLAPI_URL``: With the URL of the `Control HTTP Interface`
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3. ``kapow set /response/body banana``
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--------------------------------------
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During the lifetime of the shell, the request and response resources are
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available via these commands:
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- ``kapow get /request/...``
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- ``kapow set /response/...``
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These commands use the aforementioned environment variables to read data
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from the user request and to write the response. They accept data
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either as arguments or from ``stdin``.
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4. exit
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-------
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The shell dies.
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5. response
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-----------
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``kapow`` finalizes the original request.
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.. todo::
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link to resource tree
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