microhack mac brew

Working on a Mac made my work a lot more fun. Especially when I was introduced to homebrew, the missing package manager for macOS.

MacPorts was fine, but it felt clumsy. Every tool seems to be switched to Homebrew and life was good.. Except when you encounter that one tool you need but is not available in brew…

Meet Gits

An example of this is the great shell script made by Roy Lines: gits. A shell script to share contribution between two git accounts when pair programming.

Unfortunately you have to install it by getting a remote bash script and add it in your /usr/local/bin directory with root rights.

$ sudo wget https://raw.github.com/roylines/gits/master/gits.sh -O /usr/local/bin/gits
$ sudo chmod ugo+x /usr/local/bin/gits
$ gits

When I see something like this, it’s another hurdle for using great scripts. It’s a good practice to check these scripts, before putting them into your bash with execution rights. Sometimes, I’m to lazy to do that.. Also I always tend to forget these scripts, so they are never updated and never removed. Your system becomes a mess.

More people did not like that. An issue was raised with a question whether it could be installed with homebrew..

How can it install it on mac? I would prefer to use homebrew.

Well, let’s help Adam!

Create our own tap

Correct format

First step is to change the structure of your script so it can be used for brew. Scripts need to be in the bin/ directory so that is the first thing we need to do.

Simply moving the script to the bin directory..

https://github.com/JeroenKnoops/gits/commit/4de9197fe1e24b751af2a1fe214b4259bf256c49

Release the script

You have to create a release of your script. You can do that by drafting a new release

Once you have a release, we need the SHA-256 checksum of the release to ensure a proper version of the download. Browse to the release and copy the name of the tar-file (in our case: https://github.com/JeroenKnoops/gits/archive/0.1.0.tar.gz)

Download the tar and generate the SHA-256.

$ wget https://github.com/JeroenKnoops/gits/archive/0.1.0.tar.gz
$ shasum -a 256 0.1.0.tar.gz
13b778bf5a7f92285f54179cd88bea4b39f661a3de47a7ff0a84b9aa5d865962  0.1.0.tar.gz

We will need this SHA-256 for our formula.

Define the Formula

We have to define the formula. This can be done by creating a repo called homebrew-tap in your own github repo. It’s best practice to put some information in the README of this repo about the Formulas which are defined.

In our case:

## homebrew-tap
Homebrew tap with formula for installing the following:

- [gits](https://github.com/jeroenknoops/gits)


#### Add this tap
`brew tap jeroenknoops/tap`


#### Install
- gits: `brew install gits`

In the /Formula directory you must create a ruby file with the definition, in our case: gits.rb

class Gits < Formula
  desc "A shell script to share contribution between two git accounts when pair programming."
  homepage "https://github.com/jeroenknoops/gits"
  url "https://github.com/JeroenKnoops/gits/archive/0.1.0.tar.gz"
  version "0.1.0"
  sha256 "13b778bf5a7f92285f54179cd88bea4b39f661a3de47a7ff0a84b9aa5d865962"

  def install
    bin.install "bin/gits"
  end
end

Push the repo to github and we’re ready to go.

Test it

Now people can use the script by installing it with homebrew. It’s still in my private homebrew-tap, so people first have to tap into our private tap.

brew tap jeroenknoops/tap

After that they can install gits with brew install gits

I do not want to tap into someone’s tap

To even raise the level of trust of the script / tool and install convenience, you can also put the Formula directly into the homebrew-core. Now people don’t need to tap into someones private tap. This will require some extra steps, like adding tests.

Brew has a way to test your formula by doing: brew audit --new-formula gits

This will show you what you still need to do, before you can submit it to homebrew. You can also find more information on that in the Formula-Cookbook

Improvements

There are more improvements I should make to release it to homebrew. F.e. add dependencies to git. For now I’m not going to dive into that. Homebrew has good documentation on that: https://docs.brew.sh/Formula-Cookbook

Conclusion

I really liked the way homebrew is set up. I like the way they name things, like brew, tap and bottle. By adding my own bottle I’ve learned how homebrew is working and now I even feel more confident in using it. I like the fact that only bottles with tests and with the proper dependencies check can be added in the core homebrew formulas.

Homebrew cask

Homebrew has another great feature, called homebrew cask. No more: “To install, drag this icon..“. Now you can install tools like atom or 1password by simply calling: brew cask install atom…

More info