This is a step-by-step guide to build a command-line tool to manage multiple git repos, and learn modules such as

In addition, I will cover engineering practices such as packaging and continuous integration.

This command-line tool has two functionalities:

  1. display information of all the registered repos side by side;
  2. delegate git commands for any number of repos from any working directory.

The official version is called gita. It has about 200 lines of code and over 700 stars on Github.

gita

I break up the project into 5 milestones

The rest of this post is a brief overview.

milestone 1: basic CLI

Here the goal is to build a command-line interface (CLI) using the argparse module. Specifically, we will implement three sub-commands add, rm, and ls, to

  • add / remove repos
  • display names and file paths of registered repos

The intended behavior is shown in the following example, where I denote the command-line input with $ and the output with >.

$ gita add /a/b/repo1 /a/d/repo2
> 2 repos are added.
$ gita ls
> repo1 repo2
$ gita ls repo1
> /a/b/repo1
$ gita rm repo1
$ gita ls
> repo2

milestone 2: git integration

Here we will add a sub-command ll, which displays information such as repo name, branch name, edit status, commit message for all repos. For example,

$ gita ll
> repo1 master *_    A nice new feature
> repo2 hot-fix *    Fix some bug

Under the hood, each piece of information comes from executing a git command using the subprocess module.

milestone 3: git delegation

In this milestone, we are going to

  • delegate git commands for repos
  • define custom git command delegation with a YAML file
  • add a super sub-command to delegate arbitrary git commands

The purpose of delegation is to run git commands

  1. from any working directory,
  2. in batch.

For example, gita pull some-repo executes git pull for some-repo, and gita fetch runs git fetch for all repos.

This is the most fun milestone where we build powerful features upon the infrastructure laid out in the previous milestones.

milestone 4: speedup

Here we will use asyncio library to speedup the git command delegation for multiple repos. You are free to use the alternative libraries to achieve the same goal.

milestone 5: miscellaneous topics

Here the topics include writing shell script for command auto-completion, and marketing an open source project.

general references