README
¶
go-kube
This repository contains Golang implementation of dynamic config injection in Kubernetes cluster.
Requirements
- kubectl
- minikube
- go v1.18+
Compiling the Code
go mod tidy
go build -o ./app ./cmd/kube/
Setup
Start the minikube virtual machine and set the env
minikube start
eval $(minikube docker-env)
This will create docker images inside the minikube vm.
Create Docker image
Build the docker image to run inside the container.
docker build -t gokube:v1 .
Change the tag v1 when updating the image. Also change the image field in sample-pod.yaml when deploying updated image. Remember all the images will be lost after deleting the vm.
Start Kubernetes Cluster
If you have RBAC enabled on your cluster, use the following snippet to create role binding which will grant the default service account view permissions.
kubectl create clusterrolebinding default-view --clusterrole=view --serviceaccount=default:default
Use the following command to create configmap from configmap/sample-configmap.yaml file.
kubectl create -f configmap/sample-configmap.yaml
Use the following command to create a pod from sample-pod.yaml file present inside the repository.
kubectl apply -f sample-pod.yaml
Check the status of pod using
kubectl get pods
Access the shell
Now get the shell to container to test the config client
kubectl exec --stdin --tty configmap-tester -- /bin/bash
Run the following from / to execute app.
./app
Open new shell with minikube docker env for next steps.
Update the config
Modify existing fields or add new fields to sample-configmap.yaml under the data section.
Use the following command to upate the configmap object in kubernetes cluster.
kubectl replace -f configmap/sample-configmap.yaml
Now you should be able to see the new configmap data printed on the shell where ./app was executed.
Deleting Resources
kubectl delete pods configmap-tester
kubectl delete configmaps sample-config
To delete the vm after testing use
minikube delete
Directories