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#!/usr/bin/env ruby

DISKS = %w(/ /something /somewhere/else)

DISKS.each do |d|
  (fs,blocks,used,available,cap,mount) = %x[df -P #{d}].lines.drop(1).first.split
  cap = cap.to_i
  puts "alert on #{fs} at #{mount} (#{cap}%)" if cap > 85
end

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#!/usr/bin/env ruby
require 'maildir'
 
class Maildir
  def subdirectories
        dirs = Dir.glob(File.join(@path,"*")).find_all{|a|File.directory?(a)}
        dirs.map{|a|Maildir.new(a)}
  end

  def read_all!

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#!/usr/bin/env ruby1.9.1
# encoding:utf-8
#
require 'ostruct'
require 'optparse'

vm = OpenStruct.new {}

vm.memory = 1
vm.cpu = 1

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For some reason, this didn't work with the standard GUI bluetooth tools, so I did the following

1. Run the command-line bluetoothctl tool
2. type "agent on"
3. type "scan on"
4. press the button on your keyboard, the light should flash if it's not paired with anything else
5. type "devices" (this shows the list of devices)
6. type "trust xxxx" where xxxx is the keyboard MAC
7. type "connect xxxx" where xxxx is the keyboard MAC
8. type "pair xxxx" where xxxx is the keyboard MAC

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TBS6280 with PCTV DVB-S2 USB Stick

I've recently struggled to get the following two pieces of DVB hardware to work together on the same machine:

• TBS 6280 Dual-Tuner DVB-T2 PCI-Express card (Amazon)
• PCTV DVB-S2 USB Stick (Amazon)

The instructions below apply to Debian Wheezy (7.0) with the [wheezy-backports][wb] repository enabled

The problem is this: Linux 3.2 (available from [wheezy-backports][wb]) comes with a [driver][em28xx] which works fine for the DVB-S2 USB stick, but doesn't come with any drivers at all for the TBS6280 (they

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Static OpenVPN configuration between a single pair of hosts

So you've got two boxes, separated by some kind of network that you're not in control of, and you'd like to encrypt traffic between them. You're not going to have multiple clients connecting to each other, just these two boxes.

As of OpenVPN 2, it's possible to configure the hosts in peer-to-peer mode, with static keying, meaning that the actual VPN setup is super easy:

1. Install OpenVPN (>=2) on both boxes, the standard Wheezy version is fine.
2. Generate a static key as follows: openvpn --genkey --secret /path/to/somewhere/secret.key
3. Copy the secret key to both boxes over a secure channel (e.g SSH)
4. Create /etc/openvpn/p2p.conf on both boxes as show in box1.vpn.cnf and box2.vpn.cnf below

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So uwsgi is pretty crazy:

# ./bin/uwsgi --help|wc -l
857

I'm using it under runit to manage some graphite processes, the problem I was having, was that I simply couldn't get it to restart with sv t, or stop with sv d.

Turns out, this is because UWSGI's default behaviour is to "brutally reload" when it receives the TERM signal, unlike most other things you'd use under runit which would normally die.

Luckily, one of uwsgi's 857 options fixes this:

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Hello

Things

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Apache Weirdness

Today I've spent a fairly large amount of time trying to track down a weird Apache edge-case, related to how self-referential URLs are generated. This is mostly-relevant if you're running Varnish (or any HTTP proxy really), and Apache 2.4 (although this probably affects other versions of Apache as well).

The configuration I'd normally use for Varnish/Apache is this:

[client] -> [varnish on port 80] -> [apache on high port, e.g 8080]

This normally (in my experience) works fine, and can be fairly transparent to the user.

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Sudo Weirdness

In a continuing series of documenting weird things that I find on Linux in case I have to come back to them in the future, today I came across some weirdness when trying to do something very specific with sudo.

The [sudoers man page][sudoersman] is long and complicated, it's even mentioned in an [XKCD Comic][xkcdsudoers].

In this case, I wanted to express the following:

Users in a specified group, "managed", must be able to execute /usr/bin/git as a specific (non-root) user, "person", without specifying a password.