The inspiration came from this project, which is also going to be its main purpose. I also have an odd fascination with vacuum tubes, and this looks like a big one.

The case has an LED inside that's hooked up to the GPIO pins. However, as of this writing I haven't assigned the LED to do anything but just chill out inside the tube. The inspiration link above features a script that'll get it to blink when files are synced. Since all we're doing here is just building a case, get ready for a lot of pictures and some text.

As you can probably guess the HDMI is inaccessible with the glass dome, but totally accessible with the metal shield/grid thing. For what I intend on using this Pi for there's no need for me to use the HDMI or GUI desktop. If you want to use that component of the Pi, you will likely be using the Pi without the glass dome. The good news to this setup is that without the GUI desktop running the Pi has some more resources to use!

Step 1: Materials

You will need:

An old industrial light fixture. I found this one at an antique shop, but you can probably find them online as well.
A base. I'm using an aluminum tin box.
Raspberry Pi with all the fixings (USB power, Ethernet, USB thumb drive). I'm going to be SSH'ing into the Pi as its main job is to just host files on the web, so no need for the HDMI or a display.
One LED. Mine is a 10mm 1.9v orange LED.
330 ohm resistor 1/4watt. To protect the LED from the Pi and vice versa.
Jumper wire.
Bolts. To secure your fixture to the base.
Random parts that look cool. This/these are optional.

Step 2: Get Building

The first thing you're going to want to do is measure, cut and mount your fixture. You should measure it, unlike myself who just winged it and had to make an extra hole.

If you're following my lead and going with an aluminum case, be sure you have the tools to cut through it. Mine wasnt that thick so I could punch a hole with a nail then use tin snips to cut out the space. Also if you use metal, be sure to sand down, or bend the edges so you don't cut yourself or your future cables.

I mounted my fixture to the box using some small bolts. If yours lacks this you may want to consider a wood base or if you have the tools, make your own mounts.

Once the mounting area is done, cut a little slot for the cables at the back. Also being sure to get rid of sharp edges.

Step 3: Dress Rehersal

Once everything is in place it's time to test fit everything. If it looks good move on. I had to add some corkboard (not shown in the images) to the inside of the fixture to hold the Pi in place.

Step 4: Wire Up the LED

So as you can see mine has a fancy metal hat, that's an old microphone protector...thingy. You can also see the resistor, 330 ohm 1/4 soldered to the positive (anode). The other end of this jumper wire will connect to #18 on the GPIO pins, however its really up to you where it goes. The negative (cathode) goes to the ground pin on the Pi's GPIO. Be sure to look up where on your Pi these pins are.

The other stuff in the images are just some old not-sure-what-to-do-with parts that are hot glued to the corkboard. Once it's all glued in place it's time to get the Pi!

Step 5: Finishing Up

If you haven't wired up your Pi, now is the time. Connect your power, ethernet, USB and GPIO jumpers to the correct ports and pins. Then put it together.

This step might take a while to get right, basically you have to get everything in place then slip on your cover. Doing this myself was a little easier than expected.

Again I don't plan on using the HDMI, but if you do this particular setup could prove to be difficult to use. But for what I intend on using this Pi for, it works perfectly for me.