Use Case The current cloud era is dominated heavily by Kubernetes (k8s). While the DevOps team manages App lifecycle (deploy, scale, upgrade, downgrade, etc.), the App developer needs to build a similar environment locally. So before shipping the App, developer is required to ensure DevOps lifecycle is not impacted by any of the changes s/he makes. So it is very much necessary for a Developer to have a local k8s cluster for testing. In short, this blog post demonstrates the following flow. Assumption You have , and installed on your host. docker kubectl KinD You have go version go1.20.3 installed on the host. However, older version should work too. This complete setup is build on Ubuntu 22.04.2 host. If you are using another OS/platform, then you might need to modify the commands accordingly. Let Start... Prerequisite Setup Clone the repo [~]# git clone https://github.com/simplyatul/godevsetup.git [~]# cd godevsetup Now using KinD, create local k8s cluster with a control plane node and two worker nodes. [~/godevsetup]# kind create cluster --config ./kind-local-k8s-cluster-baremin.yaml --name local-dev Creating cluster "local-dev" ... ✓ Ensuring node image (kindest/node:v1.26.3) 🖼 ✓ Preparing nodes 📦 📦 📦 ✓ Writing configuration 📜 ✓ Starting control-plane 🕹️ ✓ Installing CNI 🔌 ✓ Installing StorageClass 💾 ✓ Joining worker nodes 🚜 Set kubectl context to "kind-local-dev" You can now use your cluster with: kubectl cluster-info --context kind-local-dev Have a question, bug, or feature request? Let us know! https://kind.sigs.k8s.io/#community 🙂 You can see that the control plane node and worker nodes are installed and running as separate containers. [~/godevsetup]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 9d2f27169e21 kindest/node:v1.26.3 "/usr/local/bin/entr…" About a minute ago Up 47 seconds local-dev-worker2 2b198d465d81 kindest/node:v1.26.3 "/usr/local/bin/entr…" About a minute ago Up 47 seconds local-dev-worker 96f3a760a02a kindest/node:v1.26.3 "/usr/local/bin/entr…" About a minute ago Up 47 seconds 127.0.0.1:33519->6443/tcp local-dev-control-plane Step 1 - App Development I have written a simple App in Go. You can do this in any language of your choice. The App exposes a ReST API on port 8080 and returns the hostname. Check the code. You can run the App locally using and then hit the following command from another terminal. GitHub go run main.go [~]# curl localhost:8080 Hostname: ubuntu-jammy Once you complete the coding, commit it. Optionally, you can push it to the remote repo as well. Step 2 - Containerize The App Build the docker image [~/godevsetup]# docker build -t godevsetup:latest . Run it locally and check once [~/godevsetup]# docker run --rm --name godevsetup -p 8080:8080 godevsetup:latest # From another terminal [~/godevsetup]# curl localhost:8080 Hostname: 48143ca71c90 Step 3 - Push Image Into Your Cluster Here we will push the container image onto the cluster nodes created by KinD [~/godevsetup]# kind load docker-image godevsetup:latest --name local-dev Image: "godevsetup:latest" with ID "sha256:aa7dbb2842050be8c1635ff117ef938e3cf7fb0c32d56d9a7fe16ca73fda0f62" not yet present on node "local-dev-worker2", loading... Image: "godevsetup:latest" with ID "sha256:aa7dbb2842050be8c1635ff117ef938e3cf7fb0c32d56d9a7fe16ca73fda0f62" not yet present on node "local-dev-worker", loading... Image: "godevsetup:latest" with ID "sha256:aa7dbb2842050be8c1635ff117ef938e3cf7fb0c32d56d9a7fe16ca73fda0f62" not yet present on node "local-dev-control-plane", loading... You can inspect image is loaded [~/godevsetup]# docker exec local-dev-control-plane crictl images IMAGE TAG IMAGE ID SIZE docker.io/library/godevsetup latest aa7dbb2842050 869MB registry.k8s.io/etcd 3.5.6-0 fce326961ae2d 103MB registry.k8s.io/kube-apiserver v1.26.3 801fc1f38fa6c 80.4MB registry.k8s.io/kube-controller-manager v1.26.3 cb77c367deebf 68.5MB registry.k8s.io/pause 3.7 221177c6082a8 311kB docker.io/kindest/kindnetd:v20230330-48f316cd <none> a329ae3c2c52f 27.7MB docker.io/kindest/local-path-helper:v20230330-48f316cd <none> 37af659db0ba1 3.05MB registry.k8s.io/coredns/coredns v1.9.3 5185b96f0becf 14.8MB docker.io/kindest/local-path-provisioner:v0.0.23-kind.0 <none> c408b2276bb76 18.7MB registry.k8s.io/kube-proxy v1.26.3 eb3079d47a23a 67.2MB registry.k8s.io/kube-scheduler v1.26.3 dec886d066492 57.8MB Step 4 - Deploy On Local K8s Cluster I have created a Nodeport Service along with the deployment. Check the file. Create the Service and the deployment. yaml [~/godevsetup]# kubectl apply -f godevsetup-nodeport.yaml deployment.apps/godevsetup created service/godevsetup-nodeport created You can check the Service and pods are created [~/godevsetup]# kubectl get all NAME READY STATUS RESTARTS AGE pod/godevsetup-78fbdfb985-4tmz2 1/1 Running 0 3m59s pod/godevsetup-78fbdfb985-frl2d 1/1 Running 0 3m59s pod/godevsetup-78fbdfb985-x77g4 1/1 Running 0 3m59s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/godevsetup-nodeport NodePort 10.96.245.170 <none> 9090:30123/TCP 3m59s service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 52m NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/godevsetup 3/3 3 3 3m59s NAME DESIRED CURRENT READY AGE replicaset.apps/godevsetup-78fbdfb985 3 3 3 3m59s You can also observe the App pods are created inside the worker nodes [~/godevsetup]# docker exec local-dev-worker crictl ps CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID POD a310b2cf0201d aa7dbb2842050 5 minutes ago Running godevsetup 0 66781797eb650 godevsetup-78fbdfb985-frl2d fea54fa36f629 c408b2276bb76 54 minutes ago Running local-path-provisioner 0 d03b938684afd local-path-provisioner-75f5b54ffd-k7xfb b11289f372caf 5185b96f0becf 54 minutes ago Running coredns 0 0b51dcb843021 coredns-787d4945fb-wqxst ee14e1dc8ff83 5185b96f0becf 54 minutes ago Running coredns 0 e7a1e535bb183 coredns-787d4945fb-g7xnq 99a540c5658fb a329ae3c2c52f 54 minutes ago Running kindnet-cni 0 eb134c7507011 kindnet-gmzxc aaebc183b9f6a eb3079d47a23a 54 minutes ago Running kube-proxy 0 a7b50875a469f kube-proxy-6wj5v [~/godevsetup]# docker exec local-dev-worker2 crictl ps CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID POD b2d32e5b552f7 aa7dbb2842050 5 minutes ago Running godevsetup 0 872cff6cf3ea3 godevsetup-78fbdfb985-4tmz2 9ae704f8c8669 aa7dbb2842050 5 minutes ago Running godevsetup 0 e186f3ccda549 godevsetup-78fbdfb985-x77g4 79013566e33e8 a329ae3c2c52f 54 minutes ago Running kindnet-cni 0 959abab06b391 kindnet-tg2jl 0611eaced1aad eb3079d47a23a 54 minutes ago Running kube-proxy 0 49477d56a66c8 kube-proxy-96f5x Step 5 - Verify The Functionally Since we have created a NodePort Service, we can access the service using Node’s IP First, identify the Node IPs [~/godevsetup]# kubectl get nodes -o wide NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME local-dev-control-plane Ready control-plane 58m v1.26.3 172.18.0.4 <none> Ubuntu 22.04.2 LTS 5.15.0-72-generic containerd://1.6.19-46-g941215f49 local-dev-worker Ready <none> 57m v1.26.3 172.18.0.2 <none> Ubuntu 22.04.2 LTS 5.15.0-72-generic containerd://1.6.19-46-g941215f49 local-dev-worker2 Ready <none> 57m v1.26.3 172.18.0.3 <none> Ubuntu 22.04.2 LTS 5.15.0-72-generic containerd://1.6.19-46-g941215f49 The INTERNAL-IP is the IP of the worker node. Now access the API’s ReST endpoint using any of the Node’s IP and Port (Port is mentioned as in our file) nodePort: 30123 yaml [~/godevsetup]# curl 172.18.0.4:30123 Hostname: godevsetup-78fbdfb985-frl2d [~/godevsetup]# curl 172.18.0.2:30123 Hostname: godevsetup-78fbdfb985-frl2d [~/godevsetup]# curl 172.18.0.3:30123 Hostname: godevsetup-78fbdfb985-4tmz2 Cool.. We are done. Now if you want to Enhance (or Bug-fix) your App, restart from Step 1. But before that, remove the Service and Deployment. [~/godevsetup]# kubectl delete -f godevsetup-nodeport.yaml deployment.apps "godevsetup" deleted service "godevsetup-nodeport" deleted Sign Off… This blog covers how to set up a local k8s cluster using KinD. And how can we leverage it for the App deployment and testing. Thank you for reading the post. Please comment on how you find this. Connect me on to get updates on future blog posts. Twitter Also published . here
