What is lets ?

Introduction

Lets is a task runner.

You can think of it as a tool with a config where you can write tasks.

The task is usually your set of cli commands which you want to group together and gave it a name.

For example, if you want to run tests in your project you may need to run next commands:

# spinup a database for tests
docker-compose up postgres
# apply database migrations
docker-compose run --rm sql alembic upgrdade head
# run some tets
docker-compose run --rm app pytest -x "test_login"

This all can be represented in one task - for example lets test

command:
  test:
    description: Run integration tests
    cmd: |
      docker-compose up postgres
      docker-compose run --rm sql alembic upgrdade head
      docker-compose run --rm app pytest -x "test_login"

And execute - lets test. Now everyone in you team knows how to run tests.

Why yet another task runner ?

So is there are any of such tools out there ?

Well, sure there are some.

Many developers know such a tool called make.

So why not make ?

make is more like a build tool and was not intended to be used as a task runner (but usually used because of the lack of alternatives or because it is install on basicaly every developer's machine).

make has some sort of things which are bad/hard/no convinient for developers which use task runners on a daily basis.

Lets is a brand new task runner with a task-centric philosophy and created specifically to meet developers needs.

Features

• yaml config - human-readable, recognizable and convenient format for such configs (also used by kubernetes, ansible, and many others)
• arguments parsing - using http://docopt.org
• global and per/command env
• global and per/command dynamic env - can be computed at runtime
• checksum - a feature which helps to track file changes
• written in Go - which means it is easy to read, write and test as well as contributing to project

To see all features, check out config documentation