Hex to RGB Converter

A web application written in GO that can be easily deployed on Kubernetes cluster with custom metric monitoring using Prometheus and grafana

Please read the notes at the end of the file in case you face any issues

prerequisite

Version >=0.18.0 of the Prometheus Operator requires a Kubernetes cluster of version >=1.8.0. If you are just starting out with the Prometheus Operator, it is highly recommended to use the latest version.

Step1

please ignore if the helm is already installed on both client and cluster and go to Step2

To install helm tiller service account

kubectl apply -f helm/service-account.yml To install the RBAC role for tiller deployment using helm

kubectl apply -f helm/role-binding.yml

helm init --service-account tiller --wait

Step2

Create a namespace monitoring which we will use to deploy Prometheus

kubectl apply -f monitoring/namespace.yml

Make sure helm repo is updated and we deploy the latest stable/prometheus-operator

helm repo up

To install Prometheus

helm install stable/prometheus-operator --namespace monitoring --name prometheus

in case it throws an error that one of the following mentioned CDRs already exists add the --set prometheusOperator.createCustomResource=false this will ignore the CRD installation.

• prometheusrules.monitoring.coreos.com
• servicemonitors.monitoring.coreos.com
• alertmanagers.monitoring.coreos.com
• prometheuses.monitoring.coreos.com
• podmonitors.monitoring.coreos.com

helm install stable/prometheus-operator --namespace monitoring --name prometheus --set prometheusOperator.createCustomResource=false

Step3

Build Docker image and replace username with your Dockerhub username

docker build k8s/ -t username/hex2rgb:latest

push the image to docker

docker push username/hex2rgb:latest

Step4

Install hle;m charts for Go application

To install go application

helm install k8s/go-server/helm-chart

Step5

Open service/deployment on local There are two ways to do it. Using kubectl port-forward pod port:port or make a Service which expose the deployment

example 1 get list of pods

kubectl get pods

knobby-kiwi-go-app-k8s-67df99c5cf-8sg82 1/1 Running 0 94m

kubectl port-forward knobby-kiwi-go-app-k8s-67df99c5cf-8sg82  3333:3000

and browsing it http://localhost:3333/convert/hex-rgb/ffcc77 this will return RGB equivalent RGB(255, 204, 119)

To get the deployment list (specify namespace if deployment in a specific namespace)

kubectl.exe get deployment

kubectl expose deployment knobby-kiwi-go-app-k8s --type=LoadBalancer --name=app-service

Step6

access grafana http://localhost:3000/login login id admin password prom-operator

you can add a custom dashboard and import/edit panel json and copy-paste the file ./grafana-panel.json

Notes: There are certain areas of improvement like building go application and later pushing it instead of including the go library in docker but for development, this can be useful if we not sure what OS developer might be using.