{"id":197,"date":"2020-01-17T12:08:07","date_gmt":"2020-01-17T11:08:07","guid":{"rendered":"https:\/\/blog.nubisoft.pl\/?p=197"},"modified":"2020-02-01T16:38:55","modified_gmt":"2020-02-01T15:38:55","slug":"developers-be-kind-to-your-containers-its-easy-with-kubernetes-in-docker-stack","status":"publish","type":"post","link":"https:\/\/nubisoft.io\/blog\/developers-be-kind-to-your-containers-its-easy-with-kubernetes-in-docker-stack\/","title":{"rendered":"Developers, be KIND to your containers! It’s easy with Kubernetes IN Docker stack ;)"},"content":{"rendered":"\n

Here, at NubiSoft<\/a>, most of our CI\/CD processes are configured in the cloud (after all, the name of our company obliges to something). But sometimes it is useful to deploy locally e.g. for development purposes. Having solutions built around the Kubernetes ecosystem makes it relatively problematic \u2026at least until recently.<\/h2>\n\n\n\n

So in this post, we will demonstrate how to build configuration enabling deploying Kubernetes cluster locally. Previously there existed solutions like Minikube<\/a> or kubeadm-dind-cluster<\/a> trying to approach running Kubernetes cluster but they are limited to the extent that their practical usage (not only for learning purposes) was disputable. All the more I got excited after a speech at a conference last year where a completely new approach was presented, which is KIND<\/a>. The months have passed and I finally conclude that it is already mature enough to be implemented in our team.<\/p>\n\n\n\n

When it comes to computing resources, everything I show below is run on my laptop – DELL XPS 13 with 16GB RAM and i7 processor, but in a VirtualBox environment. This environment runs Ubuntu 18 (Bionic Beaver) and has 8GB of RAM and 4 CPUs allocated. So let’s roll up our sleeves and get to work! <\/p>\n\n\n\n

First, we have to upgrade our Ubuntu Bionic OS.<\/p>\n\n\n\n

sudo apt update\nsudo apt -y upgrade<\/pre>\n\n\n\n
As Kubernetes <\/a>itself and KIND <\/a>are implemented in Golang<\/a>, we need to install the Go platform first. At the time of writing this post, the minimum version of Go required by KIND is 1.13. Let us download the proper binaries.<\/p>\n\n\n\n
wget https:\/\/dl.google.com\/go\/go1.13.3.linux-amd64.tar.gz<\/pre>\n\n\n\n
Now we need to extract the downloaded archive to a shared place in a filesystem to be available for every user,<\/p>\n\n\n\n
sudo tar -xvf go1.13.3.linux-amd64.tar.gz\nsudo mv go \/usr\/local<\/pre>\n\n\n\n
and configure environment variables – I prefer doing that for a local profile:<\/p>\n\n\n\n
nano ~\/.profile<\/pre>\n\n\n\n
At the end of the .profile file, we have to add the following lines:<\/p>\n\n\n\n
export GOROOT=\/usr\/local\/go\nexport PATH=$GOROOT\/bin:~\/go\/bin:$PATH<\/pre>\n\n\n\n
After reread of the profile file we may check if the Go language is installed and accessible.<\/p>\n\n\n\n
source ~\/.profile\ngo version<\/pre>\n\n\n\n
Now it is time to install Docker<\/a>. I prefer doing that using a dedicated repository. <\/p>\n\n\n\n
sudo apt install apt-transport-https ca-certificates curl software-properties-common\ncurl -fsSL https:\/\/download.docker.com\/linux\/ubuntu\/gpg | sudo apt-key add -\nsudo add-apt-repository \"deb [arch=amd64] https:\/\/download.docker.com\/linux\/ubuntu bionic stable\"\nsudo apt update\nsudo apt install docker-ce\n<\/pre>\n\n\n\n
Normally, when using Docker commands it is required to sudo, but to be able to use KIND commands we have to configure Docker to be usable without sudoing.<\/p>\n\n\n\n
sudo usermod -aG docker NULL<\/pre>\n\n\n\n
And to apply the above configuration without re-logging to the OS, we do the following:<\/p>\n\n\n\n
su - NULL<\/pre>\n\n\n\n
Now it is time for installing KIND.  We won’t work out much here  \ud83d\ude09<\/p>\n\n\n\n
GO111MODULE=\"on\" go get sigs.k8s.io\/kind@v0.7.0<\/pre>\n\n\n\n
 And finally, we’re ready to launch our Kubernetes cluster. Please notice that the first execution has to last a little bit because kind has to pull (i.e. download) the proper docker image. For the start let’s initialize our Kubernetes cluster with default settings.<\/p>\n\n\n\n
kind create cluster<\/pre>\n\n\n\n
After that, we can verify the default single-node configuration of just created cluster. The name of the node is kind-control-plane<\/em>.<\/p>\n\n\n\n
kind get nodes<\/pre>\n\n\n\n
To be able to interact with our cluster we need to install one more tool – namely kubectl<\/strong>. There are many ways<\/a> of doing that,  but while I’m a big fan of containerization technologies, on client machines, I try to avoid using snap packages. So I am doing it my way (notice the usage of xenial repo, as at the time of writing this post there is not a bionic one yet):<\/p>\n\n\n\n
sudo apt-get update && sudo apt-get install -y apt-transport-https\ncurl -s https:\/\/packages.cloud.google.com\/apt\/doc\/apt-key.gpg | sudo apt-key add -\necho \"deb https:\/\/apt.kubernetes.io\/ kubernetes-xenial main\" | sudo tee -a \/etc\/apt\/sources.list.d\/kubernetes.list\nsudo apt-get update\nsudo apt-get install -y kubectl<\/pre>\n\n\n\n
Now we are able to verify what pods are running in our cluster:<\/p>\n\n\n\n
kubectl get po --all-namespaces<\/pre>\n\n\n\n
And thanks to use the –all-namespaces<\/em> flag we see quite a lot of them because this command lists also all infrastructural pods.<\/p>\n\n\n\n
Ok, what if we would like to create an HA cluster with more than one node? <\/p>\n\n\n\n
With KIND it is possible and easy. All we need is to prepare the configuration file (saved as kind-multinode.yaml<\/strong>), like this shown below.<\/p>\n\n\n\n
kind: Cluster\napiVersion: kind.x-k8s.io\/v1alpha4\nnodes:\n- role: control-plane\n- role: control-plane\n- role: control-plane\n- role: worker\n- role: worker\n- role: worker<\/pre>\n\n\n\n
Now it is enough to recreate our cluster: <\/p>\n\n\n\n
kind delete cluster\nkind create cluster --config kind-multinode.yaml<\/pre>\n\n\n\n
 Let’s verify if all nodes were created:<\/p>\n\n\n\n
kubectl get nodes<\/pre>\n\n\n\n
… and voil\u00e0 \ud83d\ude09<\/p>\n\n\n\n