Category: Linux

pulseaudio-dlna + Yamaha AV Receiver RX-V573

By , 2018-09-03 15:52

It “just works!”

Install pulseaudio-dlna from Ubuntu default repos, then run pulseaudio-dlna. The first time, it failed, but I think that’s because the receiver was switched off. Console output did show it had been detected though. After switching on the receiver then running pulseaudio-dlna again, it redirected my currently playing audio to the receiver after a few seconds! So far this is the first time I’ve managed to get DLNA live streaming working with this receiver in 5 years of owning it.

Cheap, portable Linux laptop – Acer C720 Chromebook

By , 2018-09-03 15:08

Note: this post is more intended for personal reference; as such the quality of writing is not up to my standard, but I’ve decided to publish it as-is anyway since I don’t have time to review and figure it could be useful to someone.

I was looking for a good portable Linux laptop to that I could carry around without being too worried about battery life or the device getting scratched up in my bag. I tried a few different devices, including the HP Folio 13, ThinkPad X131e, GPD Pocket, Dell Latitude E7240. Finally I settled on the Acer C720 Chromebook. The main points in favour of this device are, for me:

  • Compact, thin and light (11.6″)
  • Relatively low cost (4GB RAM model can be had for under $150 CAD)
  • Proper modern low-voltage Intel Core processor (Celeron 2957U – Haswell) and not an Atom core or high-end i7
  • Dual-band Wi-Fi and Bluetooth

and the main downsides:

  • Basic TN LCD panel
  • 16GB storage
  • Runs Chrome OS
  • Chrome OS keyboard layout

The good news is the downsides are fairly easily remedied.

TN LCD Panel

The Acer C720 uses a standard 11.6″ LED backlit eDP panel. I was able to find an IPS panel to replace it on laptopscreen.com (model N116BCA-EA1). The panel replacement is fairly straightforward; care needs to be taken not to break the LCD bezel or any of the clips.

16GB SSD

The SSD on the C720 is a standard M.2 2242 SATA SSD. The M.2 slot is easily accessible after removing the Chromebook’s bottom cover.

Runs Chrome OS

The Chrome OS/Linux dual-boot process is done by using the chrx script (https://github.com/reynhout/chrx). Remember to remove the write-protect screw while the bottom cover is off.

Chrome OS keyboard layout

This was arguably the hardest part. I chose to run Xubuntu, so the steps I went through apply to that environment. Chrx by default provides good defaults, mapping the back, forward, refresh, brightness and volume keys. The big issue for me was the placement of the power button (above the backspace key)

  1. Prevent systemd-logind from handling the power button
    edit /etc/systemd/logind.conf and add the following line:
    HandlePowerKey=ignore
  2. Prevent xfce power manager from handling the power button
    xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/logind-handle-power-key -s true
  3. Allow xfce power manager to handle lid switch
    xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/logind-handle-lid-switch -s false
  4. Remap power key to Delete
    xmodmap -e “keycode 124 = Delete”
    To find the keycode, stop lightdm, startx to start a basic X session, then use xev to get the keycode for the power key.

 

Other tweaks

Consistent custom wallpaper/background for boot splash, login, and lock screen

  • gnome-screensaver uses the Gnome DE’s wallaper setting. Configure this via CLI:
    gsettings set org.gnome.desktop.background picture-uri file:///usr/local/share/wallpaper/animevillage.jpg
  • lightdm-gtk-greeter can be configured using GUI tool lightdm-gtk-greeter-settings or by editing /etc/lightdm/lightdm-gtk-greeter.conf
  • plymouth/boot splash:
    • go to /usr/share/plymouth/themes and create a copy of the xubuntu-logo directory. I called mine xubuntu-logo-mod
      sudo cp -R xubuntu-logo xubuntu-logo-mod
    • within the new xubuntu-logo-mod directory, rename and edit config files accordingly
      325 cd xubuntu-logo-mod/
      326 ls
      327 sudo mv xubuntu-logo.plymouth xubuntu-logo-mod.plymouth
      328 sudo mv xubuntu-logo.script xubuntu-logo-mod.script
      329 sudo nano xubuntu-logo-mod.script
    • replace wallpaper.png in xubuntu-logo-mod directory with desired image. I used ImageMagick’s convert tool to convert my jpg format image to png.
    • add new theme we have created as an “alternative” with higher priority
      • Find out priority and config for current theme
        sudo update-alternatives –query default.plymouth
        Name: default.plymouth
        Link: /usr/share/plymouth/themes/default.plymouth
        Status: auto
        Best: /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth
        Value: /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth

        Alternative: /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth
        Priority: 200

        Alternative: /usr/share/plymouth/themes/xubuntu-logo/xubuntu-logo.plymouth
        Priority: 150

      • Create new alternative with higher priority
        sudo update-alternatives –install /usr/share/plymouth/themes/default.plymouth default.plymouth /usr/share/plymouth/themes/xubuntu-logo-mod/xubuntu-logo-mod.plymouth 200

 

 

 

Getting LightDM/sddm to use a custom screen layout (Kubuntu/Xubuntu 18.04 – xorg)

By , 2018-04-23 12:55
    1. Adjust screen layout using your DE’s tool.
    2. Install and run arandr. arandr will read the current display layout and allow you to save it as an xrandr script.
    3. Place the script from arandr somewhere safe (I put it in /usr/local/bin).
    4. Create file /etc/lightdm/lightdm.conf.d/displays.conf with the following content:
      [SeatDefaults]
      display-setup-script=/usr/local/bin/monitorlayout.sh
      

      Where “/usr/local/bin/monitorlayout.sh” is the path to the script saved from arandr.
      For sddm, instead edit /usr/share/sddm/scripts/Xsetup.sh and add a line to have it run the same “/usr/local/bin/monitorlayout.sh” script.

      #!/bin/sh
      # Xsetup - run as root before the login dialog appears
      
      # set screen layout using Xrandr
      /usr/local/bin/monitorlayout.sh
    5. Restart lightdm or sddm
      sudo systemctl restart lightdm.service
      sudo systemctl restart sddm.service

 

My convoluted Subsonic server setup

By , 2016-05-15 21:23

Since ending my colo server plan, my Subsonic server hasn’t been running. I used to just have all my media synced to the Proxmox server I had in colo, then bind-mounted that folder to the OpenVZ container that was running Subsonic.

I’ve now moved my Proxmox/Subsonic server to a little Zotac ZBOX on my LAN that only has one local disk so I figured I wouldn’t sync all my music over locally when it could just directly access it from my new FreeNAS box. Turns out this is a little bit more complex than I thought – here are the steps I did to get it working:

  1. Get all music onto the FreeNAS box. For this I’m still using BTsync. One client is on my Mac, sharing my iTunes library, the other is in a FreeNAS jail.
  2. Install Subsonic in an LXC container on the Proxmox server.
  3. Create an NFS export on the FreeNAS server and mount it as storage on Proxmox. I just used the “Add storage” option in the Proxmox Web UI rather than adding it to fstab, because I was lazy.
  4. Configure the LXC bind mount. Essentially, in /etc/pve/104.conf :
     mp1: /mnt/pve/freenas,mp=/mnt/freenas
  5. Set up Subsonic to scan the /mnt/freenas/music folder.
  6. Realize that Subsonic has issues with non-ASCII characters in filenames. Fix it by adding “export LANG=en_CA.UTF-8” to the subsonic.sh start script.
  7. Realize that Subsonic has no access to write to the NFS share, since the GIDs on the FreeNAS box and the Subsonic container don’t match. I use GID 500 = users as my main group on FreeNAS, so I created a group freenasusers with GID 500 in the Subsonic container and added the subsonic user to this group.

Probably missed some steps, but that’s the gist of it. I really need to get my blogging and documentation back on track.

Enabling DVD playback on Ubuntu 14.04

By , 2014-08-02 21:37

I don’t really play DVDs on my PCs much anymore, but my brother have me the full boxed set of Freaks and Geeks (great show, cancelled too soon). Running on a fresh install of Ubuntu 14.04, I popped in the DVD and was prompted by “Video Player” aka Totem to install some additional codecs. I obliged, but after the installation, the DVD still wouldn’t play. It turns out that because of legal issues, the libdvdcss2 library is no longer included in the Ubuntu repositories. However, the libdvdread4 package does provide a script to easily install it.

Once you have libdvdread4 installed, run following script:

# sudo /usr/share/doc/libdvdread4/install-css.sh

Restart your video player and enjoy your DVD.

Screenshot from 2014-08-03 01:35:17

uptime

By , 2014-07-31 15:32

I noticed that my workstation has been up essentially since I made my last blog post.
129 days and counting.

 $ uptime
 15:22:40 up 129 days,  2:41,  5 users,  load average: 1.88, 1.91, 1.93

This system also hasn’t been re-installed since November 2012. The initial install was done using the Ubuntu 12.10 “Quantal Quetzal” CD on November 20, 2012. I’ve since upgraded to every interim release – 13.04, 13.10 and now 14.04, and used a host of different desktop environments and window managers (currently using i3). The PC actually hasn’t been rebooted since installing 14.04; I only restarted X.

[email protected]:/var/log/installer$ ls -l
total 1532
-rw------- 1 root   root   1303 Nov 20  2012 casper.log
-rw------- 1 root   root   3856 Nov 20  2012 debug
-rw-r--r-- 1 root   root 420116 Nov 20  2012 initial-status.gz
-rw-r--r-- 1 root   root     59 Nov 20  2012 media-info
-rw------- 1 root   root 747016 Nov 20  2012 partman
-rw------- 1 syslog adm  377562 Nov 20  2012 syslog
-rw------- 1 root   root     17 Nov 20  2012 version
[email protected]:/var/log/installer$ sudo cat media-info 
Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
[email protected]:/var/log/installer$

 

Selection_111

two-line bash script to extract all rars in a given folder

By , 2013-02-15 12:15

This script will find all .rar files in a given directory and extract them into the specified directory. Requires the unrar binary installed in PATH.

usage: unrar-recursive.sh [directory to scan] [extraction destination dir]

  • Running the script without arguments will search for all .rar files in the current directory and subdirectories and extract them all to the current working directory.
  • Running the script with only 1 argument will search for all .rar files in the specified directory and extract them into the same directory.
#!/bin/bash
if [ "$#" -eq 0 ]; then dest=$1; else dest=$2; fi
find $1 -type f -iname "*.rar" -exec unrar e {} $dest \;

Sources:

Atheros AR5005/5212, WPA encryption

By , 2012-11-07 22:08

I have a few old reliable AR5005G (5212, PCI 168c:0013) cards, both MiniPCI and Cardbus from the heyday of Wireless-G back in the early ’00s. Back then, Atheros 500x series cards were THE cards to have if you wanted to have some fun with aircrack, or if you just wanted your WiFi to actually WORK, especially under Linux. The madwifi (aka ath_pci) drivers were probably the most stable wireless drivers at the time. Even on Windows, you could use 3rd party drivers to put the cards in monitor mode and capture packets.

Times have changed and madwifi has been superseded by ath5k (and indirectly ath9k).

For some reason I decided to install Ubuntu 12.04 on an old Fujitsu Lifebook (Pentium III 600MHz, upgraded 512MB RAM, ATI Mobility Radeon M4) without built-in wireless, using a Netgear WPN511 Cardbus adapter. I expected everything to work as it did in the old days, but for some reason the WiFi wouldn’t stay connected.

It seems the hardware encryption capabilites on the card don’t quite support WPA2/CCMP-AES, even though the ath5k driver says it does. So the solution is to disable hardware encryption support:

echo "options ath5k nohwcrypt=1" | sudo tee /etc/modprobe.d/ath5k.conf

Then reboot, or reload the ath5k module (modprobe -rv ath5k, modprobe -v ath5k).

Now I can enjoy my surprisingly not-extremely-slow 10-year old laptop wirelessly.

Source: http://ubuntuforums.org/showthread.php?p=12086356#post12086356

http://madwifi-project.org/

Useful apt commands

By , 2012-10-29 14:46

apt-cache search [searchterm]

search local apt-cache for a package  containing [searchterm]

apt-file list [packagename]

lists all files associated with [packagename], even if the package is not installed

apt-file search [/path/to/file]

search for the package that “owns” [/path/to/file]

apt-cache madison [packagename]

displays all available versions of [packagename]

apt-get install [packagename]=[version]

force apt to install a specific version of a package

Automatic vpnc connection on DD-WRT

By , 2012-09-24 18:34

I sometimes have to work from home, which means using VPN. Cisco VPN works quite well, but it’s just not the same as being on the corp network.

Using a spare DD-WRT router (ASUS WL-520GU) running the VPN build of DD-WRT, I set up a persistent VPN connection. Now when I connect my work PC to this router, it behaves just like it’s on the corporate LAN.

How to do it

  1. First, get the recommended DD-WRT VPN build from dd-wrt.com and flash the router.
  2. Connect the VPN router’s WAN/Internet port to your home LAN.
  3. Make sure your router’s LAN IP doesn’t conflict with any subnets in the corp network or your existing home LAN. I used 192.168.133.0/24.
  4. Add your corporate domains and DNS servers to the dnsmasq config (Services tab)
  5. Next, customize the script at the end of this post and paste in the Administration>Commands section. Click Save Startup.
  6. Reboot the router. Wait about 5 minutes (it takes a while to start up) and verify you can ping/access servers on the corp LAN.
  7. Done!

This isn’t exactly the most stable solution, but it works and I haven’t had any disconnects so far. Also much cheaper and much less trouble than setting up a site-to-site VPN using a real Cisco router.

One sticking point is that from now on any changes to router config (DHCP, WiFi, etc.) will require a reboot. Otherwise your VPN tunnel will die and won’t come back for some reason.

Also, speeds are limited by the router’s processor. Mine is only a 266MHz ARM, so IPsec puts quite a load on it, meaning I can only sustain speeds of about 2Mbps – sadly still better than some of our WAN sites that are using T1 lines.

Script

mkdir /tmp/etc/vpnc
rm -f /tmp/etc/vpnc/vpnc.sh
#Create the VPNC startup script in /tmp
echo '
#!/bin/sh 
vpn_concentrator="your.vpn.gateway" ##enter ip or hostname of your Ipsec vpn concentrator
vpn_keepalive_host1="some.server.corp"        ##enter the ip or hostname of a computer that is only reachable if vpn connection is established.
vpn_keepalive_host2="other.server.corp"        ##enter the ip or hostname of a computer that is only reachable if vpn connection is established.
vpn_groupname="groupname"  ##enter the group name here
vpn_grouppasswd="grouppass"   ##enter the group password here
vpn_username="user"       ##enter your username here
vpn_password="pass"        ##enter your password here

#--do not edit this--
#Written by Alain R. 28.Sep.2007
#updated by Matthieu Y. 2012-09-24
vpnc-disconnect
rm -f /tmp/etc/vpnc/vpn.conf
#Create vpnc config file
echo "
IPSec gateway $vpn_concentrator
IPSec ID $vpn_groupname
IPSec secret $vpn_grouppasswd
Xauth username $vpn_username
Xauth password $vpn_password
" >> /tmp/etc/vpnc/vpn.conf
# allow dnsmasq to forward dns replies for LAN subnets
sed -i "s/stop-dns-rebind//g" /tmp/dnsmasq.conf
killall dnsmasq
dnsmasq --conf-file=/tmp/dnsmasq.conf 
#Check if we can ping the IPs specified above
pingtest1 () {
 ping -q -c1 $param1 >> /dev/null
 if [ "$?" == "0" ]; then
       echo 0 #reachable 

 else
	echo 1 #not reachable
 fi
}

pingtest2 () {
 ping -q -c2 $param2 >> /dev/null
 if [ "$?" == "0" ]; then
       echo 0 #reachable 

 else
	echo 1 #not reachable
 fi
}
doloop=true

while [ $doloop==true ]; do
			param1=$vpn_keepalive_host1;

			if [ "`pingtest1`" == "0" ]; then
				sleep 300
			else
				param2=$vpn_keepalive_host2;
				if [ "`pingtest2`" == "0" ]; then
					sleep 300
				else
					doloop=false
					vpnc-disconnect
					vpnc /tmp/etc/vpnc/vpn.conf --dpd-idle 0
					sleep 1
					if [ "`pingtest1`" != "0" ]; then
						sleep 10
					fi
					tundev="`ifconfig |grep tun |cut -b 1-4`"
					iptables -A FORWARD -o $tundev -j ACCEPT
					iptables -A FORWARD -i $tundev -j ACCEPT
					iptables -t nat -A POSTROUTING -o $tundev -j MASQUERADE
					sleep 9
				fi
			fi
done

return 0;
' >> /tmp/etc/vpnc/vpnc.sh
chmod 700 /tmp/etc/vpnc/vpnc.sh
/tmp/etc/vpnc/vpnc.sh&

References:

 

 

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