Personal DevOps #2

Even though, I wanted to do this structured, beginning with this topic is quite a mess. You have to set up everything and pull all pieces together before one can start working properly.

Getting a Server

First of all, I picked up a new root server. I will install Ubuntu 18.04 LTS on this particular one. I found a great offer at Netcup, where I just ordered a new root server with unlimited traffic.

That way, I can start moving bit by bit from my old, handcrafted and home-brewed server to the new one instead of replacing the old server. Once everything works fine, I will migrate the data and change the DNS entries to the new server.

macOS as Ansible Control Machine

When starting with such a project, one should expect problems from the very first moment. For me, it started already when I wanted to install Ansible on macOX. Why I’ve chosen Ansible over Chef and Puppet will be covered later.

There is no native Ansible package for macOS available. Instead, you can use Homebrew to do so. Assuming Homebrew is already installed, the following command should do the job.

> brew install ansible

However, for me, it already ended in some errors:

xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools),
missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

As most of the time the latest macOS version Mojave might be the reason, running

> xcode-select --install

the command line tools will be installed as part of Xcode. Once accomplished, the homebrew command should work like a charm. Eventually, Ansible is available on my local laptop which is now my control machine.

Setting up the SSH Access

Usually, I deactivate all password-based logins on a server and allow only RSA-key-based logins. To generate the key, you can follow the instruction on ssh.com.

To upload the key, ssh-copy-id is needed. However, once again this is not available on macOS and you have to install it using

> brew install ssh-copy-id

Now you can upload the key using

> ssh-copy-id -i ~/.ssh/key user@host

So far I have planned this was the only step necessary on the server. All future settings, including deactivating password only access should be set using Ansible scripts.

Setting up a Repository

As a (former) developer, I almost don’t do anything without putting my stuff into a revisioning system. For my Ansible scripts, I decided to set up a private GitHub repository. Although I use GitLab and Subversion at the moment at work as well as running a Subversion server at home, I meanwhile put almost everything int GitHub repositories. Therefore Github comes just in quite handy.

Why Ansible?

For automation, there are several frameworks. One major advantage of Ansible is the fact, only a single so-called control machine is needed. There is no further Ansible infrastructure needed. Once you have installed Ansible as described above you are ready to go. For Puppet, you need again to deal with a server and agents an eventually you stick with running daemons. While this is a feasible approach e.g. to manage my team’s 100 servers at work, this is an overkill for personal use. Same with Chef. That’s the reason, I decided to use Ansible as it seems a quite feasible approach for personal use with little overhead while being an approach with the least attack vectors.

If not being familiar with ansible, I recommend watching the following 14-minute video, which gives you a good overview of Ansible’s capabilities. You might want to skip the last four minutes as it deals with Red Hat’s Ansible Tower which targets enterprises.