Handling SSH Protocol Links in Chrome (on Linux)

As a network engineer, I have been annoyed by not being able to click on SSH links in webpages for years while running Linux.

After digging in a bit I was able to find this solution which works for SSH in Chrome.

I’m running Ubuntu 16.04 in my setup.

My SSH URL links look like this:

ssh:///user@host:port

Here is the process I used to get these links working.

#Check which handler is setup for SSH
xdg-mime query default x-scheme-handler/ssh

#Write code for new handler
cat << EOF > ~/.local/share/applications/ssh.desktop
[Desktop Entry]
Version=1.0
Name=SSH Launcher
Exec=bash -c '(URL="%U" HOST=\$(echo \${URL:6} | cut -d ":" -f1) PORT=$(echo \${URL:6} | cut -d ":" -f2); ssh \$HOST -p \$PORT); bash'
Terminal=true
Type=Application
Icon=utilities-terminal
EOF

#Apply New handler for SSH
xdg-mime default ssh.desktop x-scheme-handler/ssh

#Confirm new handler has been applied
xdg-mime query default x-scheme-handler/ssh

Manually Installing Plugins in Vagrant

It looks like there have been some changes lately in Vagrant from v 1.7.4 –> 1.8.4 that allow me to no longer install plugins locally.

I kept getting failures that looked like this:

vagrant plugin install ./vagrant-libvirt-0.0.33.gem 
Installing the './vagrant-libvirt-0.0.33.gem' plugin. This can take a few minutes...
Bundler, the underlying system Vagrant uses to install plugins,
reported an error. The error is shown below. These errors are usually
caused by misconfigured plugin installations or transient network
issues. The error from Bundler is:

Could not find gem 'vagrant-libvirt (= 0.0.33)' in any of the gem sources listed in your Gemfile or available on this machine.

Warning: this Gemfile contains multiple primary sources. Using `source` more than once without a block is a security risk, and may result in installing unexpected gems. To resolve this warning, use a block to indicate which gems should come from the secondary source. To upgrade this warning to an error, run `bundle config disable_multisource true`.Warning: this Gemfile contains multiple primary sources. Using `source` more than once without a block is a security risk, and may result in installing unexpected gems. To resolve this warning, use a block to indicate which gems should come from the secondary source. To upgrade this warning to an error, run `bundle config disable_multisource true`.

So based on my read of https://github.com/mitchellh/vagrant/issues/5643 there is a work around to host a local gem server to make the install proceed that way and sure enough it works. Here are the steps for that workaround as it pertains to the vagrant-libvirt plugin for Vagrant.

sudo apt-get install ruby-dev zlib1g-dev

#Download and build the Vagrant-libvirt plugin
git clone https://github.com/vagrant-libvirt/vagrant-libvirt.git
cd vagrant-libvirt/
gem build vagrant-libvirt.gemspec

#workaround for Local Gem Install Failure
#https://github.com/mitchellh/vagrant/issues/5643

#Install it locally
sudo gem install ./vagrant-libvirt*.gem

#Serve the locally installed gems on localhost:8808
sudo gem server & 

#Install the vagrant plugin while pointing at a local gemserver
vagrant plugin install vagrant-libvirt --plugin-source http://localhost:8808

# Turn off the gem server
kill %1

Autoplaying Files in Kodi Isengard

Almost all the affects of the change in naming from XBMC to Kodi have been realized at this point except for a few small areas. One of those areas is using the on-box API to send commands into Kodi or automate certain actions.

In my case I was trying to automatically play a file as soon as my Kodi player boots. To do that you simply place a file with the right content in the right place.

My System Details:

  • Hardware: Raspberry Pi 2 /w Edimax EW-7811UTC AC600 Wifi Adapter
  • Software: OpenELEC v6.0.3 (Kodi 15.2 Isengard)

Specifically, create a file called autoexec.py in the /storage/.kodi/userdata/ directory.

import xbmc
xbmc.executebuiltin( "PlayMedia(smb://192.168.1.20/usenet/Baby_Stream.strm)" )
xbmc.executebuiltin( "PlayerControl(repeat)" )

If you’re trying to test the script on the CLI via ssh by using the python interpreter you might notice that calls to import the xbmc module fail.

OpenELEC:~ # python
Python 2.7.3 (default, Feb 29 2016, 21:17:05) 
[GCC 4.9.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import xbmc
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
ImportError: No module named xbmc
>>>

This is expected because the xbmc module is not exposed to the default python path.

Testing your Script:

In order to test your script try having Kodi send it through it’s python namespace using the kodi-send command:

OpenELEC:~ #kodi-send -a "RunScript(/storage/.kodi/userdata/autoexec.py)"

Quick and easy automation in Kodi. To see other functions that can be called either via kodi-send or  automated in xbmc.executebuiltin statements, check Kodi’s official docs on the subject.

Udev Network Interface Renaming with no Reboot

While working on the Topology_Converter for work I came upon several lessons with Udev. The topology_converter project essentially takes input (from a graphiviz file) and builds a network topology with proper interface names. In order to make the interface names work there is a script which spits out udev rules.

Writing Udev Rules

With Udev you can rename interfaces using a number of parameters which are defined in rules. Rules should be stuck in the “/etc/udev/rules.d/70-persistent-net.rules” file to follow convention but you could technically stick them anywher in the rules.d directory.

To see all of the possible criteria that can be matched upon for a given network interface, use the command below replacing “eth0” with your interface of choice.

udevadm info -a -p /sys/class/net/eth0

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

looking at device '/devices/pci0000:00/0000:00:19.0/net/eth0':
 KERNEL=="eth0"
 SUBSYSTEM=="net"
 DRIVER==""
 ATTR{addr_assign_type}=="0"
 ATTR{addr_len}=="6"
 ATTR{address}=="54:ee:75:22:3d:70"
 ATTR{broadcast}=="ff:ff:ff:ff:ff:ff"
 ATTR{carrier}=="0"
 ATTR{carrier_changes}=="1"
 ATTR{dev_id}=="0x0"
 ATTR{dev_port}=="0"
 ATTR{dormant}=="0"
 ATTR{duplex}=="unknown"
 ATTR{flags}=="0x1003"
 ATTR{gro_flush_timeout}=="0"
 ATTR{ifalias}==""
 ATTR{ifindex}=="2"
 ATTR{iflink}=="2"
 ATTR{link_mode}=="0"
 ATTR{mtu}=="1500"
 ATTR{netdev_group}=="0"
 ATTR{operstate}=="down"
 ATTR{proto_down}=="0"
 ATTR{speed}=="-1"
 ATTR{tx_queue_len}=="1000"
 ATTR{type}=="1"

looking at parent device '/devices/pci0000:00/0000:00:19.0':
 KERNELS=="0000:00:19.0"
 SUBSYSTEMS=="pci"
 DRIVERS=="e1000e"
 ATTRS{broken_parity_status}=="0"
 ATTRS{class}=="0x020000"
 ATTRS{consistent_dma_mask_bits}=="64"
 ATTRS{d3cold_allowed}=="1"
 ATTRS{device}=="0x15a2"
 ATTRS{dma_mask_bits}=="64"
 ATTRS{driver_override}=="(null)"
 ATTRS{enable}=="1"
 ATTRS{irq}=="56"
 ATTRS{local_cpulist}=="0-3"
 ATTRS{local_cpus}=="0f"
 ATTRS{msi_bus}=="1"
 ATTRS{numa_node}=="-1"
 ATTRS{subsystem_device}=="0x2227"
 ATTRS{subsystem_vendor}=="0x17aa"
 ATTRS{vendor}=="0x8086"

looking at parent device '/devices/pci0000:00':
 KERNELS=="pci0000:00"
 SUBSYSTEMS==""
 DRIVERS==""

</code>

You can see there are quite a few options to match on. When remapping physical interfaces on Linux, I strongly recommend adding the match for PCI to make sure this interface is mapped to the PCI bus in some way. The concern when not using the PCI match (as shown below) is that if these physical interfaces are to take part in bridges or bonds with vlans or sub interfaces…. in that case your bridge or bond may inherit mac addresses from a physical interface and there will be a collision in the renaming process which means your interfaces may be left named “renameXX” or something like that.

Here are some sample Udev rules for a given series of interface renaming operations.

#### UDEV Rules (/etc/udev/rules.d/70-persistent-net.rules) ####
ACTION=="add", SUBSYSTEM=="net", ATTR{address}=="44:38:39:00:00:1a", NAME="swp2", SUBSYSTEMS=="pci" 
ACTION=="add", SUBSYSTEM=="net", ATTR{address}=="44:38:39:00:00:12", NAME="swp1", SUBSYSTEMS=="pci" 
ACTION=="add", SUBSYSTEM=="net", ATTR{address}=="44:38:39:00:00:49", NAME="swp48", SUBSYSTEMS=="pci" 
ACTION=="add", SUBSYSTEM=="net", ATTR{address}=="44:38:39:00:00:42", NAME="eth0", SUBSYSTEMS=="pci" 
ACTION=="add", SUBSYSTEM=="net", ATTR{address}=="08:00:27:8a:39:05", NAME="vagrant", SUBSYSTEMS=="pci"

Applying the New Rules

Now that you’ve written the new rules it’d be nice to apply them without having to reboot.

That can be a little complicated and is totally disruptive to networking traffic likely on all interfaces but the procedure looks like this:

  1. Detect the driver used by each interface that requres a remap. The easiest way is to use
    $ ethtool -i eth0
    driver: e1000e
    version: 3.2.6-k
    firmware-version: 0.2-4
    expansion-rom-version: 
    bus-info: 0000:00:19.0
    supports-statistics: yes
    supports-test: yes
    supports-eeprom-access: yes
    supports-register-dump: yes
    supports-priv-flags: no

    You could potentially use this technique:

    $ basename $(readlink /sys/class/net/eth0
    /device/driver/module)

    or this one:

    $ basename $(readlink /sys/class/net/+interface+/device/driver)

    YMMV  depending on the driver in use.

  2. Remove the driver that is shared/used by each interface that is to be remapped (other interfaces that are using that driver may get caught in the crossfire here).
    $ modprobe -r e1000e
  3. Run the following command to detect the newly installed rules
    $ udevadm control --reload-rules
  4. Apply the new rules with the last command
    $ udevadm trigger

Applying the new rules with the trigger operation will also reinitialize the driver that you’ve previously removed.

Presto you’re done.

Using Nautilus in Ubuntu 14.04 and 16.04 as a Box Client

It is not well known that the Nautilus file manager in Gnome can be used as a client to access box shares. This article seeks to document how to set up that connectivity mostly as a reminder for when I need to do it later.

proceedure1). Open Nautilus and select “Connect to Server”

Select Connect To Server in Nautilus File Browser
Select Connect To Server in Nautilus File Browser

2). Fill in the “Server Address” as follows:

davs://username%40yourdomain.com@dav.box.com/dav

note: The ‘%40’ is the character encoding for ‘@’ and you must leave that there exactly as shown.

Selection_004

 

 

 

 

 

 

3). Click Connect and, when prompted, enter your external password for Enterprise Box. This should bring up a File Browser window showing you the files you have in your Box space.

 

If your password doesn’t work… you may need to create an “External Password” for use with apps (like Nautlius) that do not have access to your single sign-on (SSO) system.

1). Log into your Box account from the website.

2). At the upper right, click your name. From the drop-down menu, click Account Settings.

3). Near the bottom, under “Create External Password”, click Edit password. and save it when finished.

4). Try this password in the above procedure.

 

Heavy Duty (and Cheap) Workbench

After months of searching on Craigslist I was not able to find a 7+ foot workbench that was made of solid wood. I was getting increasingly frustrated so I began looking online for different plans to make my own.

Workbench Criteria:

  • 7 to 8 ft long ~2ft deep
  • THICK wooden top (I wanted more for aesthetics than anything else)
  • Heavy Duty Construction ( I didn’t want to think twice about putting 500 pounds on it )

After a while of searching I found an excellent starting point in an old Family Handyman article. I referenced this article for all the steps on the construction of the base and tabletop with several modifications:

  • I wanted a 2×6 base mainly for looks but also because I intend to keep this workbench for my lifetime and want it to last at least that long.
  • I also added some shelving to the crossbars underneath because it should have been there from the start and I had some leftover lumber from my earlier garage shelving project.
  • I added a 45 degree chamfer on the table top since this is just pine and could otherwise be pretty easily marred on the corners.
  • Lastly I inset a T-square in the corner of the table because I had an extra one lying around and I thought it could be useful.

Cost Breakdown

Materials:

  • $61 — Lumber
  • $50 — Used Vise off of Craigslist (looked new to me)
  • $20 — Lag Bolts and Hardware
  • $5 — Consumables (Wood Glue)
  • FREE — 3″ Deck Screws — I had these leftover
  • FREE — L Square — I had an extra

Tools:

  • $50 — New Table Saw Blade
  • $56 — (3) 36″ Clamps

~$250 total mostly in new tools that I would have bought for something else. All in all I could not be happier with the result, it was just what I wanted and meets every one of my needs.

Bringing the lumber home

This little car has never carried so much lumber in its entire life. So many 2x4s but I made it all in one trip!

Constructing the workbench

Adding the Finishing Touches

Finished.

IMG_20140731_225532
Just what I always wanted for this space.

Building A Solid Oak Picture Frame

 

Had some solid red oak lumber left over from the Babyroom Built-in Project and decided to make a picture frame for my wife for Christmas. This was my first attempt at this sort of thing but it came out excellent!
Solid Oak Picture Frame

Materials:

  • Wood
  • Wood Glue
  • Pre-cut Glass (link below)
  • Pre-cut Matting (link below)
  • Glazier Points
  • Stain
  • Polyurethane or Lacquer
  • Sandpaper (60,120,220 grits)

Tools:

  • Table Saw
  • Bench Router
  • Power Sander
  • Clamps (at least 3 big ones)

Step 1). Determine your Frame Size

What I learned here is that a 16×20 frame has the internal dimensions (aka “id”) of 16×20. Or in other words if you’re building a 16×20 frame, your piece of glass is going to need to be 16×20.

Also if you want to include a border of matting you can matte down a size. The idea being that you could frame an 11×14 photo in a 16×20 frame and the difference between the two sizes can be found as a pre-cut piece of matting.

Step 2). Purchase Matting and Glass

I have been using a store called Jerry’s Artarama for years and they are excellent. They’re more of an art supply store but they have everything one could ever need in the area of framing. They also have some really knowledgeable staff that can give you guidance on how to complete any framing project. If you don’t have a local store near you, you can buy online directly from Jerry’s. These were the items I used for this project:

Lastly there’s always Amazon. Amazon sells all kinds of pre-cut matting that you can have delivered to your door. The only downside for ordering online with something like this is you can’t get a great look at the precise color until it arrives. I like to pick my stain and my matting at the same time for the best results.

Step 3). Cut Lumber To Frame Width

In my case I started with some larger width boards. So I set up the table saw and made them a bit more narrow, in my cases the frame width was about 2.25 inches.

Step 4). Route the Inside Edge of the frame with a Rabbit Bit

rabbetAfter cutting my lumber to the proper width, I got out my router table and went to the store to get a rabbet bit.

In my case I purchased a rabbet bit that would carve out a 1/2″ x  1/2″ channel. I ran this along one of the sides of all my lumber that was previously cut to width.

Step 5). Cut the 45 Degree Corners

At this point it is a matter of cutting your frame pieces so that you can fit your glass and matte. As I was cutting I took my matte board out several times just to make sure everything would fit without much play.

Step 6). Wood Glue and Clamp

Most folks secure frame corners together with several joining techniques however I was using red oak for this project which is a very porous species of wood and I didn’t think it would be necessary to add the extra strength.

To confirm the theory, I cut a few extra corners and glued them together with Elmer’s Wood Glue to test the strength of the glue alone. After the glue hardened over night, I examined the test corner by hand at first but when I was unable to break it by hand I put it in the vice and only then was I able to break it.

Glue alone is more than enough for a picture frame made of oak.

As the corners are drying I strongly recommend adding a ton of long clamps to all sides to further firm everything up. I even added some C-clamps to the individual corner pieces to make sure they would stay flush with one another. I had 7 clamps set up as mine was drying, 4 c-clamps, one for each corner, and 3 big long clamps to span the sides.

Step 7). Sand Sand Sand

After the glue was set over night I started the sanding process. Before I started, I made sure to empty the sander of anything that might have been in the collection bag beforehand for reasons I will explain in the next step.

At this point I began sanding all sides with 60, and 120 grit to hone out any large imperfections with the glue-up.

Step 8). Fill in Any Gaps

Since I was using glue alone and I am not perfect there were some very small gaps in my corners. Since appearance is everything with a picture frame I wanted to make sure to take care of these.

Using the sanding dust in the orbital sander dust collection bag I mixed-up a paste of wood glue and oak sawdust. I then used my finger and a toothpick to apply this slurry wherever there were any imperfections in the corner glue up.

This technique also allows the corners to take some of the stain in, where as glue by itself would not absorb any stain.

Step 9). Sand Again

After letting the second glue-up set it was time to sand again. This time I went right to the 220 grit sand paper and smoothed the entire piece out.

Step 10). Stain And Poly

I chose to use a nice red oak stain and some aerosol polyurethane but you can finish your frame however you like. I was tempted to just use some dutch oil and see how that looked but despite having purchased a bit of dutch oil I never seem to want to use it when I have the choice of stain.

Two coats of stain were applied several hours apart.

Then an additional 24 hours of drying time for the stain at which point the first coat of poly was applied. I hung the piece from the ceiling of my workshop while applying the poly so I could get a nice even coating and do all sides at once. I waited another 5 hours or so before applying the second coat of poly, then let the piece air dry for a couple days and voila, the frame was complete.

Step 11). Mount Picture

I still haven’t done this for my new frame but I’ve performed these last two steps for other frames. Basically it boils down to these little items called glazier points, you insert the glass, followed by the matte board, then your picture, I tend to use a bit of masking tape on the edges of the picture to keep it from sliding around in the matting.

Step 12). Apply the Backing

After taping the picture you insert the backer board (usually cardboard for larger frames) and start to move around the edge of the frame adding glazier points on each side.

I use a flat-head screwdriver and a hammer to tack the glazier points in place behind the backer board to hold everything in place.