Makefile¶

pyramid_oereb uses GNU-Makefile a lot to setup itself and its components. This section is a try to describe the structure of the used Makefile.

A Makefile is constructed of so called targets. Most often a target represents a file which should be created. So you the line defines the commands how to create the development.ini file which is necessary to run DEV instance of pyramid_oereb.

To stay with this line in the Makefile you can see that a mako-render command is called with several variables from a virtual environment. Thats a bit interesting. More interesting is the dependency which is defined right on the same line of the target: install

It refers to the install target some lines above which has a dependency requirements-timestamp which refers to a target some lines above … and so forth.

Important to know is that GNU Make keeps track of target files. So if some change was made for instance to your requirements.txt file to update a pypi package a simple make build is enough to setup your project with it and provide it in your VENV. If you call make build for another reason and say the requirements.txt file was not touched by you the complete targets which depend on this file are omitted.

This is a really powerful tool which - used correctly - can save a lot of work compared to write the same logic in a shell scripte or in a python script. In the best case it leads to reproducible environments independent of the machine it is issued on.

However, because it is a bit different how it works, people often struggle with its usage and avoid to use it at all.

The following sections should help you to understand better what the Makefile provides you when you call a decent target. It shows the dependency-target-system in a graph.

green elements are files which are expected to be there (e.g. setup.py)
red elements are files which will be created through the target or which are meta targets (“phony” - no files are created)