Rancher 2.0 in lxc

Note: Updated slightly now rancher 2.0 is GA.

There are a couple of tricks, but it is possible to get the Rancher beta running in an lxc container with some tweaks. Firstly, the lxc profile needs to be tweaked:

lxc profile edit default

The defaults that worked for me were:

Start a shell in a docker container that refuses to start

Sometimes, containers die, and you need to look inside to resolve, this one liner allows a quick way to adjust the 'container_name' and it will drop you right into the container so you can look around, then cleanup afterwards.

CTR="container_name"; docker commit $(docker ps -a | egrep " ${CTR}$" | awk '{ print $1 }') test; docker run --rm -ti --entrypoint=bash test; docker rmi test

Or maybe as a script, something like:

dnsmasq in ubuntu zesty

The systemd included in ubuntu zesty doesn't work nicely with dnsmasq by default, which is a pain if you are a developer and want to setup a local .test or similar domain. The way around this is to change the /etc/systemd/resolved.conf and uncomment/add a line like:


Then setup you dnsmasq as normal, probably by creating a file /etc/dnsmasq.d/test with the contents:

Getting <ctrl>-<tab> to work in gnome-terminal

If you are used to using <ctrl>-<tab> and <ctrl>-<shift>-<tab> in firefox, chrome, etc, and want to have the same in gnome terminal, its a little tricky, but these commands should get things setup so that it works for you.


gsettings set org.gnome.Terminal.Legacy.Keybindings:/org/gnome/terminal/legacy/keybindings/ prev-tab '<Primary><Shift>Tab'

gsettings set org.gnome.Terminal.Legacy.Keybindings:/org/gnome/terminal/legacy/keybindings/ next-tab '<Primary>Tab'



Enabling <alt>-<space> in Ubuntu for Ulauncher

If you are wanting to use <alt>-<space> as the key for the excellent Ulauncher with Ubuntu, there are a couple of tweaks that you need to do:

1. Ensure that CompizConfig Settings Manager is installed:

apt-get install compizconfig-settings-manager

2. Start the CompizConfig Settings Manager

Go to General, General options, Key bindings and disable Window Menu which is assigned <alt>-<space> by default.

Ubuntu - Large external USB drive slow to unmount, eject or sync

When using a USB HDD (probably a stick as well), there can be large delays when using a Ubuntu machine while waiting for data to be synced to the disk. After much googling, trying different filesystems and tweaking mount options, the solution that worked was:

echo $((16*1024*1024)) > /proc/sys/vm/dirty_background_bytes
echo $((48*1024*1024)) > /proc/sys/vm/dirty_bytes

Which i found here: http://unix.stackexchange.com/questions/107703/why-is-my-pc-freezing-while-im-copying-a-file-to-a-pendrive/107722#107722 http://lwn.net/Articles/572911/


Find all email that a user sent via postfix mail.log

I needed to find all the email that a user sent with only the postfix mail.log. This simple script does that. There is probably an easier way :-)

#!/bin/bash USERNAME=$1 for i in `grep -A2 $USERNAME mail.log | \
grep message-id | cut -d'<' -f2 | cut -d'>' -f1`; \
do grep "$i" /var/log/mail.log | grep "to=" | awk '{ print $7 }' | \
cut -d'<' -f2 | cut -d'>' -f1; done | sort | uniq -c


A low resource usage Pandora player - Pianobar

Pandora has become my go to choice of music player some time ago, but having a browser window open just to play music strikes me as we little crazy. Pithos is one alternative and does a reasonable job, but I was looking for something lighter and I found it with Pianobar. Theres a bunch of features, it works a treat, and is very lightweight compared to Pithos. Give it a try, maybe you'll prefer a non-gui too.