apt-upgrade

I used to use a 2 command 1 liner to update my system:

sudo apt-get update && sudo apt-get dist-upgrade

That was easy enough to type out now and then. But over time it grew to include removing and cleaning downloaded packages as well.

Then there’s the matter of knowing if an update requires a system restart.

The lazy me put it all into one bash script and made it globally accessible and executable:

Placed it in  /usr/local/bin/apt-upgrade  and made it executable with  sudo chmod +x /usr/local/bin/apt-upgrade .

Now I can run  sudo apt-upgrade on all of my servers and it’ll update things as well as letting me know if a reboot is required.

Unable to install sass gem on CentOS 6.9 with Ruby 2.4

Something changed recently, preventing a VM from fully provisioning. Tracking it down was a bit of a PiTA.

OS: CentOS 6.9
Ruby: 2.4 – installed from source with the gearlingguy.ruby ansible role
Gems to be installed: sass

The issue is with the ffi ruby gem.

Looking at the releases in github, a recent release updated the required version of autoconf installed on the system. Fine for modern systems, not so much for CentOS 6.9.

The solution is to install the ffi ruby gem with the version prior to this recent change:

This then allows sass to be installed without complaint!

Setting up an On-Premise instance of Amon

NewRelic no longer offers server monitoring for free accounts, so what are the alternatives when you’re on a skin-flint budget?

There are lots, but I’m not going to review any of them. Instead, I’ve been tasked with getting Amon running on a DigitalOcean droplet so that it might be appraised.

Amon can either be used as a SAAS, hosted by Amon themselves. Or it can be run “On-Premise” by cloning the git repo to your own server.

The On-Premise instructions didn’t work for me as-is on a fresh Ubuntu 16.04 server. So I present to you here the result of getting it going!

Assumptions:

  1. You know what you’re doing with Linux on a server.
  2. You can create your own VPS, or have dedicated hardware, that will only be used for server monitoring.
  3. MongoDB is installed from Mongo’s repo, not Ubuntu’s.
  4. Let’s Encrypt is used for the SSL certificate.
  5. The FQDN used for accessing the Amon instance matches the server’s full hostname (easy enough to change by altering FULL_HOSTNAME).
  6. Postfix is used on localhost as the MTA (alter the content of /etc/opt/amon/amon.yml if that’s not to be the case).

The following took the instructions of https://docs.amon.cx/onpremise/ and then extended/tweaked them to create a fully working server.

So the initial script I wrote turned out better suited to being a collection of scripts. And to keep them together, I’ve created a new GitHub repo to house them.

If you find it useful, great! If you would like to help make the installation provisioning system better, PRs are very welcome 🙂

https://github.com/bigcalm/amon-server

Vagrant: sudo access and the hostsupdater plugin

Bringing up a vagrant machine is as easy as vagrant up.

If you’re a web developer, it would be nice if it were to add the private network IP address to /etc/hosts of the host machine. Thus giving you instant access to http://my-awesome-site.dev/

This doesn’t happen by default, but it is possible with the use of a plugin. The one I like to use is vagrant-hostsupdater.

Install thus:

When you bring up the vagrant machine, it will now automatically add the VM’s name to /etc/hosts.

As /etc/hosts is owned by root (and I hope you aren’t running everything as root), you have to provide sudo access to edit /etc/hosts.

Either you manually enter your sudo password every time you run vagrant up, or you can add some rules to sudoers.

This will work on Ubuntu type systems. Paths to sh and sed may be different on your own system.

Copy/paste the following into /etc/sudoers.d/vagrant and chmod the file to 0440

A similar system can be used if you want to make use of nfs for the file sharing with the VM.

Again, this works for Ubuntu systems, you mileage may vary.

Copy/paste the following into /etc/sudoers.d/vagrant and chmod the file to 0440

You will now be able to use nfs without having to enter your sudo password on each vagrant up and vagrant halt.
 

Multi-screen with Ubuntu Unity

This tweet has to have been the most popular thing I have ever said. At time of posting it has gained 80 retweets, 25 favourites and many replies/questions.

Work recently bought me a new workstation, so the 1st thing I always do is to dual boot with Ubuntu.

Some might consider me an edge case user. Though as a developer, I like a rather particular set-up. That is, 3 wide screen monitors with the central one rotated 90 degrees for my IDE.

This is something that Windows gets right without having to dig about installing things. While Linux distros have always struggled (in my experience).

Because my tweet gained quite a few questions, I thought it best to reply to them here for everybody to see.

@ankitvad asks what specs. I use for Ubuntu.
Titanium Rimless Glasses from Spex4Less.com
Couldn’t resist, sorry 🙂

Dell Alienware X51
CPU: i7
Memory: 8GB
Graphics card: nVidia GeForce GTX 660
Storage: 1TB HDD (Windows) 120GB SSD (Linux)
Mouse: Logictech M570 trackball
OSs: Window 7 SP1, Ubuntu 12.10 64bit
Monitors: 2 x 22″ Dell, 1 x 22″ LG

All 3 monitors are connected to the one graphics card. Two by DVI and one by HDMI.

As I said, this is a working system from a fresh install without updates being applied or any 3rd party packages installed. So the default graphics driver is doing quite well these days 🙂

The only downside to this is that the default graphics driver is dog slow and won’t let me play games on Steam 😉 The next step will be to get the nVidia binary driver working.

Chroot SFTP home dir

Example user ‘iain’

Adding extra fields to FOSUserBundle / SonataUserBundle

Sadly, this isn’t really documented (at time of writing).

Adding new protected variables to your User.php entity will not actually create database entries when you try to do a doctrine:schema:update.

While one still needs to have the protected variables in this entity class, along with getters and setters, the actual creation work is within UserBundle/Resources/config/doctrine/User.orm.xml

Here is an example for adding a foreign key:

Ubuntu 12.04 LTS on Bytemark VM

If, like me, you can’t wait for Ubuntu 12.04.1 to be released, you can force an upgrade of your favourite OS OS.

If you are going from the previous LTS 10.04, then the -d is important. Otherwise there would be no upgrade to offer.

The upgrade process should go smoothly enough. Except for when it comes to the kernel.

Bytemark VM’s make use of kernels that sit outside of the VM itself.

I didn’t realise this until I tried to fix syslog doing this:

Even if you update grub, it’ll be ignored. Instead, follow the instructions here: http://www.bytemark.co.uk/support/technical_documents/kernelchange?tags=VirtualMachine

At the time of writing, I chose 3.2.0-kvm-i386-20110111 as it’s fairly close to the kernel being used by other Ubuntu 12.04 machines I have.

Your mileage may vary, but I hope this helps somebody else with the same trouble.