Raspberry Pies aren't a new thing here, and in this post I´d like to show you how I made a Docker Swarm Cluster with a few of them. Well, the part that most impressed me in the RPIs is that the v3 has 4 cores and 1 GB of RAM. It means that with 5 of them, you can get 20 cores and 5 GB of memory. I know they're not Power or x64 cores, and you won´t run a large Java Application Server in it but... you can do a lot of things at home.
I am divided this project in 2 instructables. The first one (this) is about how to make a "rack" and all the hardware I used in the cluster.
The second one is how to setup the software and a few tests with Docker Swarm Mode. I decided to do this because it would be easier to find information about wich part of the project you might be interested in.
I hope you enjoy it. If there's any thing else I can help, please feel free to contact me =).
Step 1: List of Materials
For this project, you´re going to need.
1 - Structural Aluminum Frames (20mmx20mm) - As much as you need for your rack size
2 - M3 screws and nuts for the aluminum frame
3 - 90 degrees angle mount holders
4 - 2.5mm screws and nuts for the RPIs
5 - The frame and the RPI blades
I attached a zip file with the parts I draw in Sketch up. There are also an ppt file with the measures and cad files (they are sketch exports, so I am not sure if they are 100% compatible to autocad or other cad tools).
The designed files are for RPI 3 and a few things must be redesigned in the files:
1 - The screw holes must be at the same size as the screws (M3) I didn´t know I got the wrong measures before getting the parts, so I had to fix them with a drill.
2 - RPI 3 holes are 2,75mm, and the screws and nuts I had to fix them in the blades were 3mm. So I had to also drill RPI again.
Step 2: The Mount Rack
The first of this process is to put all the nuts in their places, inside the aluminum frames. For the parts I designed, you're going to need 10 screws and nuts for each blade holder (top and bottom), 2 pairs for each side of the frame, 2 for the top fix structure and a pair for each connection between the frameholder and t he blade holder. It's pretty straight-forward.
Next part, fix the frame in the sides, let the screws loose because your're going to need to adjust the frames to match the positions. When everything is aligned, just fix the screws and then fix the entire structure to the place they will stay.
Step 3: The Blades
This step is also pretty straight forward.
For each blade, fix the nylon spacers in the back hole with the nylon nuts. Then attach the RPI in the blades, ajust them in front hole and fix it with nylon screws in the back. Then fix each used blade in the mount rack with the M3 screws and the nuts you put in the previous step.
Step 4: Conclusion
Well, in this instructable I showed you how I did my RPI cluster rack. I am working on the Docker Swarm Cluster instructable and there will be described everything else your going to need.
If you have any doubts about this project, I'll be happy to respond!!!
Thanks a lot!