From 0c58b14002aa75f721d65adb684f0e0597818dc0 Mon Sep 17 00:00:00 2001 From: DarkSun Date: Wed, 11 Mar 2020 01:10:56 +0800 Subject: [PATCH] =?UTF-8?q?=E9=80=89=E9=A2=98:=2020200310=20Run=20Kubernet?= =?UTF-8?q?es=20on=20a=20Raspberry=20Pi=20with=20k3s?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit sources/tech/20200310 Run Kubernetes on a Raspberry Pi with k3s.md --- ...n Kubernetes on a Raspberry Pi with k3s.md | 203 ++++++++++++++++++ 1 file changed, 203 insertions(+) create mode 100644 sources/tech/20200310 Run Kubernetes on a Raspberry Pi with k3s.md diff --git a/sources/tech/20200310 Run Kubernetes on a Raspberry Pi with k3s.md b/sources/tech/20200310 Run Kubernetes on a Raspberry Pi with k3s.md new file mode 100644 index 0000000000..2079a18983 --- /dev/null +++ b/sources/tech/20200310 Run Kubernetes on a Raspberry Pi with k3s.md @@ -0,0 +1,203 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Run Kubernetes on a Raspberry Pi with k3s) +[#]: via: (https://opensource.com/article/20/3/kubernetes-raspberry-pi-k3s) +[#]: author: (Lee Carpenter https://opensource.com/users/carpie) + +Run Kubernetes on a Raspberry Pi with k3s +====== +Create your own three-node Kubernetes cluster with these easy-to-follow +instructions. +![A ship wheel with someone steering][1] + +For a long time, I've been interested in building a [Kubernetes][2] cluster out of a stack of inexpensive Raspberry Pis. Following along with various tutorials on the web, I was able to get Kubernetes installed and working in a three Pi cluster. However, the RAM and CPU requirements on the master node overwhelmed my Pi. This caused poor performance when doing various Kubernetes tasks. It also made an in-place upgrade of Kubernetes impossible. + +As a result, I was very excited to see the [k3s project][3]. K3s is billed as a lightweight Kubernetes for use in resource-constrained environments. It is also optimized for ARM processors. This makes running a Raspberry Pi-based Kubernetes cluster much more feasible. In fact, we are going to create one in this article. + +### Materials needed + +To create the Kubernetes cluster described in this article, we are going to need: + + * At least one Raspberry Pi (with SD card and power adapter) + * Ethernet cables + * A switch or router to connect all our Pis together + + + +We will be installing k3s from the internet, so they will need to be able to access the internet through the router. + +### An overview of our cluster + +For this cluster, we are going to use three Raspberry Pis. The first we'll name **kmaster** and assign a static IP of 192.168.0.50 (since our local network is 192.168.0.0/24). The first worker node (the second Pi), we'll name **knode1** and assign an IP of 192.168.0.51. The final worker node we'll name **knode2** and assign an IP of 192.168.0.52. + +Obviously, if you have a different network layout, you may use any network/IPs you have available. Just substitute your own values anywhere IPs are used in this article. + +So that we don't have to keep referring to each node by IP, let's add their host names to our **/etc/hosts** file on our PC. + + +``` +echo -e "192.168.0.50\tkmaster" | sudo tee -a /etc/hosts +echo -e "192.168.0.51\tknode1" | sudo tee -a /etc/hosts +echo -e "192.168.0.52\tknode2" | sudo tee -a /etc/hosts +``` + +### Installing the master node + +Now we're ready to install the master node. The first step is to install the latest Raspbian image. I am not going to explain that here, but I have a [detailed article][4] on how to do this if you need it. So please go install Raspbian, enable the SSH server, set the hostname to **kmaster**, and assign a static IP of 192.168.0.50. + +Now that Raspbian is installed on the master node, let's boot our master Pi and **ssh** into it: + + +``` +`ssh pi@kmaster` +``` + +Now we're ready to install **k3s**. On the master Pi, run: + + +``` +`curl -sfL https://get.k3s.io | sh -` +``` + +When the command finishes, we already have a single node cluster set up and running! Let's check it out. Still on the Pi, run: + + +``` +`sudo kubectl get nodes` +``` + +You should see something similar to: + + +``` +NAME     STATUS   ROLES    AGE    VERSION +kmaster  Ready    master   2m13s  v1.14.3-k3s.1 +``` + +### Extracting the join token + +We want to add a couple of worker nodes. When installing **k3s** on those nodes we will need a join token. The join token exists on the master node's filesystem. Let's copy that and save it somewhere we can get to it later: + + +``` +`sudo cat /var/lib/rancher/k3s/server/node-token` +``` + +### Installing the worker nodes + +Grab some SD cards for the two worker nodes and install Raspbian on each. For one, set the hostname to **knode1** and assign an IP of 192.168.0.51. For the other, set the hostname to **knode2** and assign an IP of 192.168.0.52. Now, let's install **k3s**. + +Boot your first worker node and **ssh** into it: + + +``` +`ssh pi@knode1` +``` + +On the Pi, we'll install **k3s** as before, but we will give the installer extra parameters to let it know that we are installing a worker node and that we'd like to join the existing cluster: + + +``` +curl -sfL | K3S_URL= \ +K3S_TOKEN=join_token_we_copied_earlier sh - +``` + +Replace **join_token_we_copied_earlier** with the token from the "Extracting the join token" section. Repeat these steps for **knode2**. + +### Access the cluster from our PC + +It'd be annoying to have to **ssh** to the master node to run **kubectl** anytime we wanted to inspect or modify our cluster. So, we want to put **kubectl** on our PC. But first, let's get the configuration information we need from our master node. **Ssh** into **kmaster** and run: + + +``` +`sudo cat /etc/rancher/k3s/k3s.yaml` +``` + +Copy this configuration information and return to your PC. Make a directory for the config: + + +``` +`mkdir ~/.kube` +``` + +Save the copied configuration as **~/.kube/config**. Now edit the file and change the line: + + +``` +`server: https://localhost:6443` +``` + +to be: + + +``` +`server: https://kmaster:6443` +``` + +For security purpose, limit the file's read/write permissions to just yourself: + + +``` +`chmod 600 ~/.kube/config` +``` + +Now let's install **kubectl** on our PC (if you don't already have it). The Kubernetes site has [instructions][5] for doing this for various platforms. Since I'm running Linux Mint, an Ubuntu derivative, I'll show the Ubuntu instructions here: + + +``` +sudo apt update && sudo apt install -y apt-transport-https +curl -s | sudo apt-key add - +echo "deb kubernetes-xenial main" | \ +sudo tee -a /etc/apt/sources.list.d/kubernetes.list +sudo apt update && sudo apt install kubectl +``` + +If you're not familiar, the above commands add a Debian repository for Kubernetes, grab its GPG key for security, and then update the list of packages and install **kubectl**. Now, we'll get notifications of any updates for **kubectl** through the standard software update mechanism. + +Now we can check out our cluster from our PC! Run: + + +``` +`kubectl get nodes` +``` + +You should see something like: + + +``` +NAME     STATUS  ROLES   AGE   VERSION +kmaster  Ready   master  12m   v1.14.3-k3s.1 +knode1   Ready   worker  103s  v1.14.3-k3s.1 +knode1   Ready   worker  103s  v1.14.3-k3s.1 +``` + +Congratulations! You have a working 3-node Kubernetes cluster! + +### The k3s bonus + +If you run **kubectl get pods --all-namespaces**, you will see some extra pods for [Traefik][6]. Traefik is a reverse proxy and load balancer that we can use to direct traffic into our cluster from a single entry point. Kubernetes allows for this but doesn't provide such a service directly. Having Traefik installed by default is a nice touch by Rancher Labs. This makes a default **k3s** install fully complete and immediately usable! + +We're going to explore using Traefik through Kubernetes **ingress** rules and deploy all kinds of goodies to our cluster in future articles. Stay tuned! + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/20/3/kubernetes-raspberry-pi-k3s + +作者：[Lee Carpenter][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/carpie +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/ship_wheel_gear_devops_kubernetes.png?itok=xm4a74Kv (A ship wheel with someone steering) +[2]: https://opensource.com/resources/what-is-kubernetes +[3]: https://k3s.io/ +[4]: https://carpie.net/articles/headless-pi-with-static-ip-wired-edition +[5]: https://kubernetes.io/docs/tasks/tools/install-kubectl/ +[6]: https://traefik.io/