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’

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.

PPTP tunnels and if-up.d

Current project requires a couple of VPN tunnels to be set up. An IPsec and a PPTP.
The IPsec will wait for another day, the PPTP is set up and ready to go.
One thing that wasn’t quite right with the tunnel though, is the static route created by PPTP missed out a large chunk of the server’s network.

Starting the tunnel sets up the routing rule of 192.168.100.111 to be sent to the tunnel.

This meant that if I wanted to get to 100.10, it wasn’t being sent.

The way around this was to add a new route: route add -host 192.168.100.10 dev ppp0

Works great from the CLI, nothing happens when added to /etc/network/interfaces or /etc/network/if-up.d/foobar.

Found out (trial and error) that it was trying to add the route as soon as the tunnel was created. This doesn’t work as the tunnel takes a few seconds to wake up.

Work around was to add a ‘sleep 5’ to /etc/network/if-up.d/foobar before the route command line.

Creating race conditions isn’t nice, but it works 🙁

Symfony 1.4 Doctrine 1.2 MS SQL Server

Web server: Linux (Ubuntu on my dev setup), Apache, PHP 5.3, Symfony 1.4, Doctrine 1.2.
Database server: Microsoft Windows 2008 Server, MS SQL Server

Trying to get Symfony to talk to the database server has been a painful experience for the last few days. But perseverance has paid off.

Lots of Googling with trial & error has resulted in actually achieving a development setup that will mirror the eventual production setup.

Short version:

  1. Follow the FreeTDS and ODBC setup instructions of http://jamesrossiter.wordpress.com/2011/03/08/connecting-to-microsoft-sql-server-using-odbc-from-ubuntu-server/
  2. Use the following in config/databases.yml

In the above snippit, replace ‘datasourcename’ with whatever you used in /etc/odbc.ini and replace ‘sqlserver’ with the name used in /etc/freetds/freetds.conf & /etc/odbc.ini

It’s late and I’ve been struggling to get this working for some time. I may expand this entry in the future if required.

References and insperation:
1) http://blog.acjacinto.com/2011/11/compiling-php-with-mssql-servers-native.html
2) http://www.microsoft.com/download/en/details.aspx?id=28160
3) http://jamesrossiter.wordpress.com/2011/03/08/connecting-to-microsoft-sql-server-using-odbc-from-ubuntu-server/
4) http://trac.symfony-project.org/wiki/HowToConnectToMSSQLServer

 

Google calendar in Mozilla Thunderbird on Ubuntu 11.10

Via the Ubuntu Software Centre:

  1. Search for thunderbird
  2. Click on the search result “Thunderbird Email” and then on the “More Info” button
  3. Enable at least the “Calendar Extension for Thunderbird – Google Calendar support (xul-ext-gdata-provider)”
  4. Install the add-ons
  5. Open your Google Calendar in your web browser
  6. In the left-hand column, under “My calendars”, hover over the calendar of choice and click the down arrow that appears after the calendar name
  7. Select “Calendar settings”
  8. Close to the bottom of the page will be the “Calendar ID” (in my case it is my full email address. Make a note of this ID.
  9. Start up Thunderbird upon completion.
  10. File -> New -> Calendar
  11. Select “On the Network” and click Next
  12. Select “CalDAV”
  13. In the Location field enter: https://www.google.com/calendar/dav/calendar.id.noted.in.point.8/events
  14. Click Next then enter a name for the calendar and set an email account against it
  15. When prompted, enter your username and password for accessing this calendar