Working with Git — How to Clone and Fork a Git Repository

December 1, 2014December 1, 2014 / Christopher Paquin / Leave a comment

So as I have stated before, I am still very new to Git. I know just enough to do a few basic tasks, but nothing much more advanced than that.

Thankfully, the process of cloning a remote Git repository is actually rather simple once you know what you are doing. Forking a repo is just as easy. Again, once you know what you are doing. Below I am going to walk you through the steps in a very simple and easy to understand way.

Cloning a Remote Repository

First lets change to a directory that we want to use as a landing zone when we download — or more accurately — clone a remote repo.

#cd /root && mkdir git

Now using the remote git URL, lets clone the fatmin github master repo @ https://github.com/Fatmin/general.git. Note that the destination of general.git name of our remote repo.

#git clone https://github.com/Fatmin/general.git

This creates the directory “general” which contains all the downloaded files, scripts, and code that we have previously checked in to our github repo. This command also initializes our pwd as a Git repo… no need to run Git init.

Forking a Remote Repository

Now lets say that we want to make a fork of the fatmin master repo. For example, lets say that we are working on a new puppet module and want to be able to test it out and then push to a new branch that we have decided to call testing.

First we need to create a new local branch. We accomplish this with the command below. As stated above, our branch is called testing.

#git checkout -b testing

Now lets grab our puppet module, script, file, code, what have you, and move it into our pwd of /root/git.

Note that even though our file is now located inside our cloned and branched repo, we need to tell Git to add it to the repo with the command below. This command will add any new files or directories in our newly created local repository.

#git add .

Now we need to commit the changes in our local repo. Here we are adding a comment along with our commit. Then we are pushing our changes back up to the remote origin (https://github.com/Fatmin/general.git) into a new branch called testing.

#git commit -m “pushing scripts to testing branch” && git push origin testing

Once we are happy with our changes, or whatever, we can then log into github and approve the merge between our master branch and our testing branch.

Puppet: How Not To Generate a Certificate with Your Correct Hostname

November 9, 2014December 1, 2014 / Christopher Paquin

So, I’ve been hacking away in my homelab as of late, building out a CentOS kickstart server, a Git server, and a puppet server. Right now, I am working on how to roll my puppet agent installs into my kickstart process. I just started on this, so I have yet to nail it down.

So currently, when kicking a VM, I am not yet setting my new CentOS node’s hostname before the install process. Sadly I am setting it manually as I am still building my kickstarts, and they are no where near where I want them to be.

Well, this whole hostname mumbo-jumbo just creates all sorts of issues for puppet… the hostname is one thing initially, then puppet installs as part of the post, and the hostname is set manually to finalize the install. Well this is no good, as you are are not going to be able to add your new node properly until you step in and provide a bit of manual persuasion.

Now while its not hard to find documentation on how to troubleshoot puppet node and master certificate issues — see here and here for example — none of it was written to help troubleshoot the mess that I had created.

Here was my specfic error.

Error: Could not request certificate: The certificate retrieved from the master does not match the agent’s private key.
Certificate fingerprint: BE:B6:B6:5E:AC:B8: ..truncated

And here verbatim, is the output that you get in response to the error above.

To fix this, remove the certificate from both the master and the agent and then start a puppet run, which will automatically regenerate a certficate.

On the master:
puppet cert clean localhost.localdomain

On the agent:
rm -f /etc/puppetlabs/puppet/ssl/certs/localhost.localdomain.pem
puppet agent -t

So we try that and it doesn’t work. The next cert I generate identifies my node as localhost again.

So heres how to fix the issue.

# rm -rf /etc/puppetlabs/puppet/ssl

Now before we generate another certificate for our node, lets test what hostname a new cert would have using the command below.

#puppet agent –verbose –configprint certname

If the command above does not spit out the correct hostname, then you my friend, are in luck. Edit the file below

# vi /etc/puppetlabs/puppet/puppet.conf

Now change the entry below by removing the localhost.localdomain, and replacing that mess with the correct hostname

certname = correcthostname.localdomain

Now kickoff a puppet run on the node

#puppet agent -t

Log into the UI, or ssh into the puppet master, and accept the new node request.

Kick off another puppet run after you have accepted the request to seal the deal and update the new node properly.

How to Create a Vagrant Base Box from an Existing One

Some brief notes on Docker

Getting Started with Git: Creating a Git Repo

October 31, 2014November 28, 2014 / Christopher Paquin

So first off let me start by saying that I know that there is a ton of information out there on how to get started with Git. Heck, when you create your repo in GitLab it spits these instructions right out in front of your nose. However, what I have found is that most instructions tell you what to do to get started with git, however they do not tell you exactly what you are doing. You end up running a few command and then sit back and try to figure out what you actually just did.

That being said, getting started with Git has been the hardest part of the process, as most of us traditional grey-beard sysadmins are not that familiar with code management. When I was first getting started in technology, there were developers and there were sysadmins, and those two worlds were extremely separate. Now, we as we enter the age of DEVOPS and automation these two worlds are once again colliding (like they did in the beginning, but more on that another day).

In my lab I decided to build a stand alone vm for Git and Puppet. After doing some research – and asking others– on how and what to do to get Git up and running with a nice front end web interface, I decided to get started by installing the GitLab Omnibus package for Centos 6. This process was quick, easy, and painless.

Once I had a working webUI up and running it was time to create my first repo. Instead of trying to accomplish this from my Fedora workstaion, I just clicked on the "New Project" button on the GitLab dashboard and created an empty repo called "General_Scripts".

Back on my Fedora workstation I created a new directory in my home dir called git, and inside that directory I created a directory called "General_Scripts" as I had done in the webUI.

Now it was time to use Git.

First off you need to configure a few global Git options. This only needs to be done once.

#git config –global user.name "Fatmin"

#git config –global user.email "fatmin@fatmin.com"

Once these global configs are set you can then you can move on to seeding your repo. Here you see my change directories to the Global_Scripts directory and tell Git to initialize this directory as a repo.

#cd Global_Scripts

#git init

Now lets create a file and add it to the repo. Here were are going to create a simple README containing a description of my new repo. The instructions do not tell you that you have to put anything in this initial file, however what good is an empty README anyway

#vi README.md

Now tell git that this file needs to be added to the "General_Scripts" repo that we created a few steps ago.

#git add README.md

Now lets commit that file with a nice little comment. Commit comments should describe what the file we added or what we changed in an existing file

#git commit -m "Added README.md"

Now we need to tell our local git command what remote repo we are going to sync to. Note my git repo url is puppet.lab.localdomain, fatmin is my user's namespace, and General_Scripts is my repo.