step-exec-lib 0.3.1

A library that helps execute pipeline of tasks using filters and simple composition

step-exec-lib

A simple library to easily orchestrate a set of Steps into a filtrable pipeline.

Disclaimer: docs are still work-in-progress!

Each step provides a defined set of actions. When a pipeline is execute first all pre actions of all Steps are executed, then run actions and so on. Steps can provide labels, so you can easily disable/enable a subset of steps.

A ready to use python app template. Based on pipenv.

How to use the library

BuildStep

The most important basic class is BuildStep. The class is abstract and you have to inherit from it to provide any actual functionality. The most important methods and properties of this class are:

• Each BuildStep provides a set of step names it is associated with in the steps_provided property. These steps are used for filtering with --steps/--skip-steps command line options.
• initialize_config provides additional config options a specific class delivered from BuildStep wants to provide.
• pre_run is optional and should be used for validation and assertions. pre_runs of all BuildSteps are executed before any run method is executed. Its purpose is to allow the abs to quit with error even before any actual build or tests are done. The method can't be blocking and should run fast. If pre_step of any BuildStep fails, run methods of all BuildSteps are skipped.
• run is the method where actual long-running actions of the BuildStep are executed.
• cleanup is an optional method used to clean up resources that might have been needed by run but can't be cleaned up until all runs have executed. cleanups are called after any run failed or all of them are done.

BuildStepsFilteringPipeline

BuildStep class provides the steps_provided property, but is not in control of whether it should be executed or not and when. BuildSteps have to be assembled into pipelines. The basic pipeline in BuildStepsFilteringPipeline, which allows you to make a sequential pipeline out of your steps and filter and skip them according to steps_provided they return and command line options --steps/--skip-steps. Each major part of abs execution is combined into a pipeline, like HelmBuildFilteringPipeline used to execute build pipeline with Helm 3 or PytestTestFilteringPipeline which is used to execute tests using pytest once the build pipeline is done.