"Squashing" commits

Jonas Gerosa — Tue, 01 Mar 2022 18:06:41 +0000

Why to squash commit?

In this article, we will cover how to squash commits but before that let's understand why would we want to do this. The most beneficial aspect of squashing commit is during the PR review where instead of having multiple commits to check we will have only one:

PR with 4 commits

In the above example, we could have only the commit message "Created component Main".

Squashing the commit

First let's check how many commits we will have to squash:

git log

In this example, we have 4 commits in our branch develop. Let's squash them with

git rebase -i HEAD~4

This will open our default editor with the following content:

pick 8bfae95 Created component Main
pick 614f223 Created style for compoent Main
pick f94c037 Bugfix on component Main
pick 5f23279 Changed some styles on component

We have a legend explaining the options available here but for the squash just leave the first line with "pick" and change all other ones to "squash" or "s".

Save your file and the next file with the commit messages will appear:

In our case we'll exclude all messages and leave only the first one:

After saving your file we now have only one commit in our local branch:

Now let's push this to create our new PR - the -f here was used because now we are behind the remote branch:

git push origin develop -f

And now we have a PR with only one commit :)

Github: Using multiple deploy keys

Jonas Gerosa — Sat, 20 Nov 2021 16:21:22 +0000

This tutorial will cover how to use multiple deploy keys with Github on a Linux/Mac system.

The first repository with deploy key

To use a repository with a deploy key first check if you have an id_rsa.pub file

ls -l ~/.ssh

if there is a key created you will see a result like this:

ls -l ~/.ssh/
total 40
-rw------- 1 jonasg domain^users  2610 nov 20 10:26 ceep_rsa
-rw-r--r-- 1 jonasg domain^users   580 nov 20 10:26 ceep_rsa.pub
-rw-r--r-- 1 jonasg domain^users   117 nov 20 10:27 config
-rw------- 1 jonasg domain^users  3389 out  4 14:34 id_rsa
-rw-r--r-- 1 jonasg domain^users   752 out  4 14:34 id_rsa.pub
-rw-r--r-- 1 jonasg domain^users 11272 nov 19 09:42 known_hosts

In the example above I have 2 different keys, one id_rsa, and another ceep_rsa. Each key is composed of a rsa file and a rsa_pub file.

For creating or first "deploy key" we will use the id_rsa.pub file. Copy the content of the command:

cat ~/.ssh/id_rsa.pub

And on your Github repository, access Settings / Deploy keys / Add deploy key. Past the key on the Key field, give it a name in the field Title, and check the permission to write to be able to push to this repository.

Adding a second deploy key

Create a new ssh key:

ssh-keygen 
Generating public/private rsa key pair.
Enter file in which to save the key (/home/jonasg/.ssh/id_rsa): /home/jonasg/.ssh/second_rsa
Enter passphrase (empty for no passphrase): 
Enter same passphrase again:

This will create a new pair of files named second_rsa and second_rsa.pub. Copy the second_rsa.pub content and paste it on Github Deploy key of the second repository on Settings / Deploy keys / Add deploy key.

Now it will be necessary to create a config file for our keys:

vi ~/.ssh/config

And add the configuration below:

Host repositoryOne.github.com
  HostName github.com
  User git
  IdentityFile /home/jonasg/.ssh/id_rsa
  IdentitiesOnly yes

Host repositoryTwo.github.com
  HostName github.com
  User git
  IdentityFile /home/jonasg/.ssh/second_rsa
  IdentitiesOnly yes

And on local git repository:

vi "local_repository"/.git/config

Change the value of URL replacing only the repositoryTwo part. The end result will be something like 'git@repositoryTwo.github.com:your-repository-path'

[core]
        repositoryformatversion = 0
        filemode = true
        bare = false
        logallrefupdates = true
[remote "origin"]
        url = git@repositoryTwo.github.com:jonas-gerosa361-react/ceep.git
        fetch = +refs/heads/*:refs/remotes/origin/*

Now you will be able to push to both repositories without passing user and password. For adding more repository just follow the same proccess for them.