Category Archives: Asides

Aside #5 – A trip down memory lane (RISC OS games)

Whilst I’ve been attempting to learn a new thing each month this year, I’ve been finding it really tricky to keep to the pretty loose schedule. As such, I though I’d try and note down every time a shiny new thing takes my interest, so that I have some idea why I’m incapable of completing a series of blog posts.

RISC OS

I’d been derailed by the idea of getting games I used to play on Acorn running on the rPi. Seeing the RISC OS as an option for the rPi OS I went straight off to find ROMS for old Acorn games I loved as a lil hacker.. And ended up watching loads of vids on youtube:

Cataclysm

Galactic Dan

(“Mmm! Thank you!”)

Xenon 2

Twin Worlds

Mad Professor

Gods

(awesome music!)

Instigator
— Seeing Mad Professor youtube clip whilst researching for the “setup” pi post made me yearn for simpler times..

Aside #4 – Accessing EC2 from my phone via SSH

Whilst I’ve been attempting to learn a new thing each month this year, I’ve been finding it really tricky to keep to the pretty loose schedule. As such, I though I’d try and note down every time a shiny new thing takes my interest, so that I have some idea why I’m incapable of completing a series of blog posts.

Accessing EC2 from a phone running ConnectBot

The ppk you use for putty/kitty/ssh doesn’t work on connectbot so you need to generate a new one from within the phone (connectbot app) and copy it over to your EC2 instance, appending it to your authorised keys file.

Generating the key

Go and install the app from the android store.

Find the app on your phone:
connectbot_icon

Generate a new key from the Manage Keys page:
connectbot_generate_public_key

Getting your file to your EC2 instance

Firstly, copy the public key to clipboard:
connectbot_copy_public_key

Then get it to your phone. There are a few ways of doing this; I pasted it into a new text file via my phone’s dropbox app and then curl-ed/wget-ed that file on to my EC2 instance (obviously logging in from a PC).

Adding it to your authorised keys

First I backed the existing authorized_keys file up:

cp ~/.ssh/authorized_keys backup_auth

Then I appended the one generated from my phone:

cat s3_id_dsa.pub >> ~/.ssh/authorized_keys

You can now log in directly from your phone without using a login:
connectbot_logged_in_to_EC2

Instigator
— needing to restart Apache whilst AFK

Aside #3 – HDMI-CEC Awesomeness

Whilst I’ve been attempting to learn a new thing each month this year, I’ve been finding it really tricky to keep to the pretty loose schedule. As such, I though I’d try and note down every time a shiny new thing takes my interest, so that I have some idea why I’m incapable of completing a series of blog posts.

HDMI CEC

I’m investigating writing apps that implement HDMI CEC protocol and can therefore be manipulated via a TV remote control only. Or an API to handle basic stuff.

HDMI pins
It looks like HDMI CEC is on pins 13 and 17 (?) of an HDMI male connector

The idea that you can plug an HDMI cable into your HDMI-CEC capable TV and not have to use a keyboard to interact with the device is fantastic for usability!

Instigator
— HDMI CEC on XBMC and BerryBoot

Aside #2 – RPi + VirtualBox = :(

Whilst I’ve been attempting to learn a new thing each month this year, I’ve been finding it really tricky to keep to the pretty loose schedule. As such, I though I’d try and note down every time a shiny new thing takes my interest, so that I have some idea why I’m incapable of completing a series of blog posts.

Running Pi distros in VirtualBox

Apparently you can run raspberryPi distros in virtualbox (totally doesn’t work though..)

Converting a .img to a .vdi:

"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" convertfromraw -format VDI path:\to\input.img path:\to\output.vdi

Instigator
— trying to get decent screenshots of the various pi OS without having to take pics of the tv

Aside #1 – EC2 WordPress Issues

Whilst I’ve been attempting to learn a new thing each month this year, I’ve been finding it really tricky to keep to the pretty loose schedule. As such, I though I’d try and note down every time a shiny new thing takes my interest, so that I have some idea why I’m incapable of completing a series of blog posts.

EC2 Issues

I’m really having problems with EC2 these days, and I’m constantly being dragged back into finding out what the problem(s) is/are..

Restarts don’t restart

Had to add entries into the rc.local to restart httpd and mysql, and also had to change the permissions on the file to allow it to be executed upon restart (sudo chmod 6755 /etc/rc.d/rc.local).

Instigator
— because the blog went down a couple of times and I didn’t notice!

Backups kill the site!

WordPress 2 DropBox – killed me. As does mysqldump in general.

DB backup

mysqldump --add-drop-table -u <username> -p <database> | bzip2 -czs > <db backup filename>.bz2

website backup

tar -cjf <site backup filename>.bz2 /var/www

Instigator
— wordpress kept telling me to upgrade to the latest version, but also had a big MAKE SURE YOU BACKUP FIRST warning; and the WordPress 2 DropBox plugin killed my EC2 microinstance.

WordPress: Alerting on high CPU usage

#!/bin/sh
#
# Script to check CPU usage and tweet me if it's over a threshold
#
if [ ` uptime | awk '{ print$10 }' | cut -d. -f1 ` -gt 50 ];
then
    sudo python /home/ec2-user/tweepy/ec2Event.py '@rposbo LOAD: ' < /tmp/load
else
    echo lo
fi

This totally doesn’t work! Uptime seems to happily report low CPU usage even when the site is dying. Maybe CPU is low and mem is high.. hmm.. may have to change that check.

Instigator
— attempting to backup wordpress keeps breaking my site, dammit!

logstash, graphite, statsd

Currently trying to get those three to work together and help me find out why the EC2 microinstance is so.. uh.. micro..

Instigator
— EC2 just keeps on dying and I need to find out why

Asides

Ooh! Shiny!!
Whilst I’ve been attempting to learn a new thing each month this year, I’ve been finding it really tricky – except for January – to keep to the pretty loose schedule.

And I don’t even have a job to take my time up at the moment!

As such, I though I’d try and note down every time a shiny new thing takes my interest, so that I have some idea why I’m incapable of completing a series of blog posts.

They’ll be short and sweet and will probably take the form:

Thing I looked at

Bit more detail

Instigator
— reason I looked at it.

Let’s see how it goes