Set up a Raspberry Pi Zero headless

If you are using the GUI (Raspian full download) and want to connect your RPi Zero to a keyboard and monitor there are probably easier ways to do this. These notes are for people that want to use a headless (no monitor and GUI) setup ready to connect to your RPi after first boot via SSH from another terminal.

Download Raspbian Lite

wget -O raspbian-lite-latest.zip https://downloads.raspberrypi.org/raspbian_lite_latest

Download link: https://www.raspberrypi.org/downloads/raspbian/

Write Image to SD Card

dd bs=4M if=2017-08-16-raspbian-stretch-lite.img of=/dev/sdb

After this step there should be 2 additional mounts (if not mount the 2 SD card partitions manually).

Set up network interfaces

Create a new config file for the wireless interface.

cd etc/network/interfaces.d/
vim wlan0.conf

Add the following to the new file (if you want to use DHCP – change to static if you want to fix the IP):

auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

Set up connection details for local wireless network

vim etc/wpa_supplicant/wpa_supplicant.conf

Check the file and ensure the network settings are as per the Wireless Network you are connecting to.

country=AU
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="SSID"
psk=HASHED_PSK_VALUE
}

You could use the clear-text PSK passphrase but I prefer not to do that in configuration files. Create a PSK hash using ‘wpa_passphrasethis older article

There could be other config values you might need depending on the network you are connecting to. More info: https://linux.die.net/man/5/wpa_supplicant.conf.

Ensure there are DNS Servers configured

sudo vim etc/resolv.conf

Add the following to the new file (or your own nameservers):

# Google's public DNS servers
nameserver 8.8.8.8
nameserver 8.8.4.4

Enable SSH Access

Create an ssh empty file in the mounted boot partition. This is necessary to enable SSH access as SSH is by default disabled on more recent versions of Raspbian.

cd boot/
sudo touch ssh

Boot RPi

Boot the Rpi by powering up and after ~30secs you should be able to connect to the IP assigned. Check your router or ise ‘nmap’ or similar to check the assigned IP:

sudo nmap -p22 -sV 10.1.1.0/24

Default login details are
UID: pi
PWD: rasbperry

My normal further setup steps for RPi 3 are here.

EDIT [2017-08-21]: One of the things necessary on later RPi’s is to turn off power saving mode on the WLAN interface.

sudo iw dev wlan0 set power_save off

Install Hugo on Ubuntu to generate static websites

Whilst there is a .DEB installer to download from the GoHugo sites I get all matter of warnings that the package is of bad quality and I am not comfortable to run these kinds of installers.

Hugo Logo

I rather install from sources in this case which is very straight forward since the main dependencies (largely GO) are in the Ubuntu main repositories.

Install dependencies

sudo apt-get install golang git mercurial python-pygments

Create environment variables

vim ~/.bashrc
#add the following 3 lines
export GOROOT=/usr/lib/go
export GOPATH=$HOME/go
export PATH=$PATH:$GOROOT/bin:$GOPATH/bin

Update Bash Environment Variables without logging out.

source ~/.bashrc

Install Hugo

go get -u -v github.com/spf13/hugo

Start using Hugo

#create new site
hugo new sitename /path/to/sitename
#change directory to site
cd /path/to/sitename
#create content page
hugo new about.md
#edit content page
vim content/about.md

Paperless Office using the Raspberry Pi

This is a follow-up on an older blog using Ubuntu.

r by rosmary, on Flickr
Creative Commons Creative Commons Attribution 2.0 Generic License   by  rosmary 

For this purpose I used a Fujitsu ScanSnap S1300i scanner as I really like the features of this series (full duplex scan as well auto document feeder as well for around $250). It’s document feeder is not a good as the S1500 we have in the office, but very compact and can be powered from USB hub.

Raspberry Pi Prerequisites

Since this will be a purely headless install designed to sit in a corner behind the scanner I am using a Base Raspian (Debian Wheezy) install (I personally like the clean minimal install via https://github.com/debian-pi/raspbian-ua-netinst the best).

apt-get install sudo vim wget wput libusb-dev build-essential git-core

Add non-privileged user account(s)

adduser USERNAME
adduser USERNAME sudo
groupadd scanner
usermod -a -G scanner USERNAME

Install Sane

The version of sane from the Raspbian repos is not working with the Fujitsu ScanJet range and needs to be built from source.

git clone git://git.debian.org/sane/sane-backends.git
cd sane-backends
BACKENDS=epjitsu ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
make
make install

Install S1300i Driver

You need to get the driver file (‘1300i_0D12.nal’) from the CD that came with the scanner. If you still have access to a CDROM drive that is. :(

mkdir -p /usr/share/sane/epjitsu/
cp 1300i_0D12.nal /usr/share/sane/epjitsu/

Check /etc/sane.d/epjitsu.conf and see if the following line is there (in my case it was already created by sane build).

# Fujitsu S1300i
firmware /usr/share/sane/epjitsu/1300i_0D12.nal
usb 0x04c5 0x128d

sane-find-scanner -q

found USB scanner (vendor=0x04c5 [FUJITSU], product=0x128d [ScanSnap S1300i]) at libusb:001:004
found USB scanner (vendor=0x0424, product=0xec00) at libusb:001:003

scanimage -L

device `epjitsu:libusb:001:004′ is a FUJITSU ScanSnap S1300i scanner

Copy libsane rules from the sane build directory to udev rules.
sudo cp sane-backends/tools/udev/libsane.rules /etc/udev/rules.d/60-libsane.rules

Logout and log in a the non-privileged user account previously created.

If the scanimage -L command works as above you have fully configured the scanner to work under that user account.

Start saned on boot-up

Edit the /etc/rc.local file and add the following line before the ‘0’ line to ensure saned is running as the non-privileged user when you have to reboot.

saned -a USERNAME

Installing Conversion Tools

sudo apt-get install imagemagick bc exactimage pdftk tesseract-ocr tesseract-ocr-eng unpaper

You can add other languages such as tesseract-ocr-deu if you require OCR support for those.

Scan to Repository Script

The script is hosted on Github: https://github.com/leogaggl/misc-scripts/blob/master/scan2repo.sh

#!/bin/bash
# Thanks to Andreas Gohr (http://www.splitbrain.org/) for the initial work
# https://github.com/splitbrain/paper-backup/
OUT_DIR=~/scan
TMP_DIR=`mktemp -d`
FILE_NAME=scan_`date +%Y%m%d-%H%M%S`
LANGUAGE="eng"
echo 'scanning...'
scanimage --resolution 300 \
--batch="$TMP_DIR/scan_%03d.pnm" \
--format=pnm \
--mode Gray \
--source 'ADF Duplex'
echo "Output saved in $TMP_DIR/scan*.pnm"
cd $TMP_DIR
# cut borders
echo 'cutting borders...'
for i in scan_*.pnm; do
mogrify -shave 50x5 "${i}"
done
# check if there is blank pages
echo 'checking for blank pages...'
for f in ./*.pnm; do
unpaper --size "a4" --overwrite "$f" `echo "$f" | sed 's/scan/scan_unpaper/g'`
#need to rename and delete original since newer versions of unpaper can't use same file name
rm -f "$f"
done
# apply text cleaning and convert to tif
echo 'cleaning pages...'
for i in scan_*.pnm; do
echo "${i}"
convert "${i}" -contrast-stretch 1% -level 29%,76% "${i}.tif"
done
# Starting OCR
echo 'doing OCR...'
for i in scan_*.pnm.tif; do
echo "${i}"
tesseract "$i" "$i" -l $LANGUAGE hocr
hocr2pdf -i "$i" -s -o "$i.pdf" < "$i.html" done # create PDF echo 'Converting PDF...' pdftk *.tif.pdf cat output "$FILE_NAME.pdf" wput $FILE_NAME.pdf ftp://uid:pwd@scanner.domain:21/Alfresco/scans/ cp $FILE_NAME.pdf $OUT_DIR/ rm -rf $TMP_DIR

Thanks go to Andi Gohr @ Splitbrain for the excellent blog that helped me to get over the sane problems and also gave me some ideas to make the scan script better (as unpaper was not doing such a good job): http://www.splitbrain.org/blog/2014-08/23-paper_backup_1_scanner_setup

Ubuntu 14.04 Amazon EC2 Cloud Desktop using LXQT

Using Amazon EC2’s free usage tier to host your own cloud desktop is a very economical way to to have a desktop at hand anytime you can not be near one. Since I quite often use Chromebooks these days when on the road this is a particular handy way should I need a full desktop for certain tasks.

Since Ubuntu 14.05 is my default desktop on my normal hardware I obviously want to have my cloud desktop running the same underlying OS. However I don’t think running Unity as the desktop interface would be appropriate via a low-bandwidth remote desktop connection. For this reason I chose LXQT. If you need total stability you probably should go for the more mature LXDE instead, but I have already tried LXQT on an old EEE PC and was very impressed by the speed and low resource usage.

NOTE (Edit: 2014-11-03): Please find an updated (and easier) version of this blog here. I was experiencing some issues with LXQT (which is understandable as it clearly states that it is not a release version)

Provision Ubuntu 14.04 LTS EC2 Instance

EC2 Choose Image

Instance details

  1. Connect to AWS Console and go to EC2 Service
  2. Choose OS Image: “Ubuntu Server 14.04 LTS” (see screenshot)
  3. Choose a “Micro Instance” if you want to use Amazon’s Free Usage Tier
  4. Choose Instance details – the defaults will generally be fine
  5. Add Storage (I generally add a separate Volume for /home but default should do)
  6. Tag instance (just give it a name to that makes sense to you in the console if you have more than one)
  7. Configure Security Group – I only set SSH which is the default (see Firewall config below). Add any other ports needed
  8. Review & Launch the instance. You need to choose your RSA Access Keys in this step. If you haven’t got any and download. DO NOT LOOSE the private keys or you will not be able to connect.

Setup Desktop & VNC

Connect via SSH to the EC2 Instance you just created (using the IP in the control panel and your RSA Key)

sudo apt-get install software-properties-common
sudo add-apt-repository ppa:lubuntu-dev/lubuntu-daily
sudo add-apt-repository ppa:gilir/q-project
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install lxqt-metapackage lxqt-panel vnc4server

Start VNC server under the desired user account. This will create the desired configuration files. Kill after the startup process is finished.

vncserver
#after successful start
vncserver -kill :1

Edit xstartup files

vim ~/.vnc/xstartup
Paste the following:
#!/bin/sh
# Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
#exec /etc/X11/xinit/xinitrc
exec openbox-session &
startlxqt &
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &

Create startup script

sudo vim /etc/init.d/vncserver
Paste the following:
#!/bin/bash
### BEGIN INIT INFO
# Provides: vncserver
# Required-Start: $syslog
# Required-Stop: $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: VNC Server Startup Script
# Description: Author: Leo Gaggl (www.gaggl.com)
### END INIT INFO
unset VNCSERVERARGS
VNCSERVERS=""
[ -f /etc/vncserver/vncservers.conf ] && . /etc/vncserver/vncservers.conf
prog=$"VNC server"
start() {
. /lib/lsb/init-functions
REQ_USER=$2
echo -n $"Starting $prog: "
ulimit -S -c 0 >/dev/null 2>&1
RETVAL=0
for display in ${VNCSERVERS}
do
export USER="${display##*:}"
if test -z "${REQ_USER}" -o "${REQ_USER}" == ${USER} ; then
echo -n "${display} "
unset BASH_ENV ENV
DISP="${display%%:*}"
export VNCUSERARGS="${VNCSERVERARGS[${DISP}]}"
su ${USER} -c "cd ~${USER} && [ -f .vnc/passwd ] && vncserver :${DISP} ${VNCUSERARGS}"
fi
done
}
stop() {
. /lib/lsb/init-functions
REQ_USER=$2
echo -n $"Shutting down VNCServer: "
for display in ${VNCSERVERS}
do
export USER="${display##*:}"
if test -z "${REQ_USER}" -o "${REQ_USER}" == ${USER} ; then
echo -n "${display} "
unset BASH_ENV ENV
export USER="${display##*:}"
su ${USER} -c "vncserver -kill :${display%%:*}" >/dev/null 2>&1
fi
done
echo -e "\n"
echo "VNCServer Stopped"
}
case "$1" in
start)
start $@
;;
stop)
stop $@
;;
restart|reload)
stop $@
sleep 3
start $@
;;
condrestart)
if [ -f /var/lock/subsys/vncserver ]; then
stop $@
sleep 3
start $@
fi
;;
status)
status Xvnc
;;
*)
echo $"Usage: $0 {start|stop|restart|condrestart|status}"
exit 1
esac

Mark the startup script as executable and create the config file for the startup script.
sudo chmod +x /etc/init.d/vncserver
sudo mkdir /etc/vncserver
sudo vim /etc/vncserver/vncservers.conf

Paste the following:
VNCSERVERS="1:USERNAME"
VNCSERVERARGS[1]="-geometry 1024x768"

update-rc.d vncserver defaults 99

Start the VNC Server

sudo /etc/init.d/vncserver start

Firewall configuration

By default VNC will use port 9501 (and subsequent ports for each session). Since VNC password authentication is generally very weak I personally do not expose this port through the firewall. I use SSH port forwarding to tunnel the VNC port through SSH (encrypted) which means only the SSH port is open and can be properly secured.

ssh -L 5901:localhost:5901 -i /path/to/your/aws/keyfile.pem YOUR.EC2.IP.ADDRESS

You should then be able to access VNC via localhost:

VNC Viewer

Hopefully you should see the LXQT Desktop:

Ubuntu LXQT

 

If you want to access this from a Chromebook this blog might help.

Installing libdvdcss on Ubuntu 13.10

With the demise of the Medibuntu repository and libdvdcss not being hosted in the main Ubuntu repos due to licensing issues a new repository is needed from 13.10 upwards. Thanks to the good folks at VideoLAN (makers of the awsome VLC Video Player) there is a ready and updated source available.

wget ftp://ftp.videolan.org/pub/debian/videolan-apt.asc | sudo apt-key add -
echo "deb ftp://ftp.videolan.org/pub/debian/stable ./" | sudo tee /etc/apt/sources.list.d/libdvdcss.list
sudo apt-get update
sudo apt-get install libdvdcss2

Disable services on boot – Ubuntu 12.04

To keep my desktop (notebook) machine light and responsive I don’t want unnecessary services starting on boot-time. Turns out Ubuntu is surprisingly cumbersome to configure in this area (compared to RedHat / Fedora).

Two services I need on my notebook, but don’t want them to start unless I require them running are MySQL and Apache. But it looks like some services are started using upstart init daemon and it appears there is no management tool for this. Services can pe prevented from auto-starting either by renaming the config file or commenting out the start line in the config file

sudo cp /etc/init/mysql.conf /etc/init/mysql.conf.modified
sudo rm /etc/init/mysql.conf

Or comment out the following line in the config file

sudo vim /etc/init/mysql.conf
#start on runlevel [2345]

Reference: http://upstart.ubuntu.com/cookbook/#disabling-a-job-from-automatically-starting

Other services are still started using rc.d such as Apache. They can be disabled using

sudo update-rc.d -f apache2 disable

Now these services should not start up when the machine boots and can be started manually
sudo service apache2 start
sudo service mysql start


EDIT (2012-08-07): thanks to a comment below from Van Luu there is a GUI option that I was unaware of called BootUp Manager (http://www.marzocca.net/linux/bum.html)

sudo apt-get install bum

Disable the Guest account from Ubuntu Login Screen

Having a guest account might be useful on a home computer, but it’s generally not what I want enabled on a notebook.

To disable the default Guest account you need to edit lightdm.conf and add a line (allow-guest=false).

sudo vim /etc/lightdm/lightdm.conf

[SeatDefaults]
greeter-session=unity-greeter
user-session=ubuntu
allow-guest=false

Tested in Ubuntu 12.04 LTS Precise Pangolin & Ubuntu 11.10 Oneiric Ocelot

Ubuntu – Google Mail (GoogleApps) as default mail client

Since Ubuntu 9.10 NetbookRemix has been released I am again finding myself using my trusty old ASUS EEE when on the road.  And  finally it seems I have found a vanilla Linux distribution that is reasonably responsive and works ‘out of the box’.

One thing I don’t need on the road (as a matter of fact on none of my equipment) is having to install & maintain some client/server mail client. Here is a workable solution to have your browser default ‘mailto:’ links to Google Apps.

Howto

System –> Preferences –> Preferred Applications

Ubuntu Preferences Screenshot

Chrome:

perl -MURI::Escape -e '$to = shift;$to =~ s/^mailto://i;exec("chromium-browser", "https://mail.google.com/a/yourdomain.tld/?view=cm&fs=1&tf=1&cmid=22&to=".URI::Escape::uri_escape($to) );' '%s'

Firefox:

perl -MURI::Escape -e '$to = shift;$to =~ s/^mailto://i;exec("firefox", "https://mail.google.com/a/yourdomain.tld/?view=cm&fs=1&tf=1&cmid=22&to=".URI::Escape::uri_escape($to) );' '%s'

Note: do not forget to replace ‘yourdomain.tld’ with your actual Google Apps domain

Here is the link to the original blog entry by David Davis (xantus77): http://xantus.vox.com/library/post/howto-use-gmail-for-mailto-links-linuxubuntu.html (Kudos !)