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searchHidden: false searchHidden: false
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## **Introduction** ## **Intro**
The _Raspberry Pi_ from it's first iteration has been a great hit. The _Raspberry Pi_ from it's first iteration has been a great hit.
Adopted by many as the computer of choice for projects, and for Adopted by many as the computer of choice for projects, and for
very good reason. The Pi is a fully fledged computer that fits in very good reason. The Pi is a fully fledged computer that fits in
@@ -47,12 +47,12 @@ than a Pi cluster.
![Insert Image of cluster here]() ![Insert Image of cluster here]()
### **Goal of this post** ### **Point of this post**
Hopefully after following this post you will have setup _Docker Hopefully after following this post you will have setup _Docker
swarm_ on a cluster of Pis **- stay even if you currently only have swarm_ on a cluster of Pis **- stay even if you currently only have
one -** and understand how to bend it to your will 🦾. one -** and understand how to bend it to your will 🦾.
### **Why** ***Docker Swarm*** ### **Why** ***Docker Swarm*** 🧐
While we can manage each docker node - _Raspberry Pi_ - individually While we can manage each docker node - _Raspberry Pi_ - individually
, **_Docker swarm_ enables us to manage all the devices from a single , **_Docker swarm_ enables us to manage all the devices from a single
main node** making managing the cluster a lot easier. main node** making managing the cluster a lot easier.
@@ -105,29 +105,68 @@ have 4 8GB nodes then you have a combined total of:
* Use smaller SD Cards try not to go below 32GB (Reccomended 64GB If money saved elsewhere) * Use smaller SD Cards try not to go below 32GB (Reccomended 64GB If money saved elsewhere)
## **BUILD TIME !!** ## **BUILD TIME !!**
Pull yourself up by your bootstraps were jumping into this one
runnig 💨
### **Image the SD Cards** ### **Image the SD Cards**
So interesting fact the CPUs used in the raspberry pi 4 use an ARM64 So interesting fact the CPUs used in the raspberry pi 4 use an ARM64
archetecture meaning they're 64bit. When looking for images of archetecture. When looking for images of Raspbian you will only find
Raspbian you will only find 32bit variants which will work however 32bit variants which will work however will not make use of all the
will not make use of all the hardware which is just a waste. 64bit hardware which is just a waste. 64bit images exist however are well
images exist however are well hidden, Dont fear 😨 **you can download hidden, Dont fear 😨 **you can download the latest images from the
the latest images from the [raspberrypi.org index](https://downloads.raspberrypi.org/raspios_arm64/images/)** [raspberrypi.org index](https://downloads.raspberrypi.org/raspios_arm64/images/)**
To write the cards I use the Raspberry Pi imager [available here](https://www.raspberrypi.com/software/). To write the cards I use the [**Raspberry Pi imager**](https://www.raspberrypi.com/software/).
once that is installed and you have the 64bit raspbian image once you have **rpi-imager** installed and you have the 64bit raspbian
downloaded do the following: image, open ```sudo rpi-imager``` and on the "CHOOSE OS" section go to
1. Click CHOOSE OS the bottom and select use custom image.
1. Click Use custom
2. Select the 64bit rasbian image and open
2. Click CHOOSE STORAGE
1. Select storage device
3. Click WRITE
We dont need to unzip the file as the tool is clever enough to > We dont need to unzip the file as the tool is clever enough to
handle that for us handle that for us
**repeat steps for number of cards you have** **Before removing the SD card, mount the boot partition - usually the
first partition, look for a file called cmdline.txt - and create an
empty file called ssh** ```sudo touch ssh``` this basically enables
SSH on the Pis first boot allowing us to access the Pis in a totally
headless manner.
### Assemble the cluster ### Assemble the cluster
So assembly is very dependant on the kit you bought, and more
often than not the stuff needed here comes with instructions or is
self explanitory. So go ahead and assemble the cluster 🛠
**There is an order of operations that I reccomend:**
* Install PoE hats onto the Pis
* Install the SD Cards into the Pis
* Assemble the case and install Pis
* plug in ethernet cables
**Now allow the Pis to boot for a few minutes so it can resize the
file system**
### **Sort out the Network bits**
This is the easy part, there are two methods we can use to set a
static IP address, one is on your DHCP server and the other is on
the device itself. Personally I prefer to set static IPs on the
device itself so I will cover that here.
To find the current ip of your Pis you can go to your DHCP server
and look for the DHCP leases for the Pis.
**SSH to the Pi** then open and edit the following files
* /etc/hosts
* edit this line with your hostname: ```127.0.1.1 mainpi```
* /etc/hostname
* edit this file with your hostname: ```mainpi```
* /etc/dhcpcd.conf
* knowing we will be using only static IPs here I delete
everything in the file add the following
* ```
interface eth0
static ip_address=10.10.10.20/24
static routers=10.10.10.1
static domain_name_servers=10.10.10.1
```
**Now reboot the pi** ```sudo shutdown -r now```