Kubernetes and Rails

Rails

A simple project to URL shortener inside the folder url-shortener

If you haven't rails installed yet, install it globally

gem install rails

Then, enter in the project directory

cd url-shortener

After that, install the dependencies

bundle install

Finally, run the app.

rails s

Kubernetes

To deploy Kubernetes on AWS with this project, you must have an .env file with your AWS credentials like the one below in this folder's root.

AWS_REGION=us-east-1
AWS_ACCESS_KEY_ID=XXXXXXXXXXXXXXXXXXXX
AWS_SECRET_ACCESS_KEY=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Than you can run:

make plan # to check deployment plan
make deploy # to deploy
make destroy # to destroy

After that, you must configure your kubectl with the created cluster data.

aws eks update-kubeconfig --name "my-eks" 

Now, we create a echoserver to test ingress with the aws-load-balancer-controller.

kubectl apply -f infra/terraform/totorial/k8s/echoserver.yaml 

If it was successful an loadbacancer will be created on demand for the ingress. Now we have to wait that loadBalancer has a endpoint to create a CNAME registry pointing to it. In my case the cname will be echo.4developments.net. because my registered domain is 4developments.net but you have to adapt and create your own.

curl http://echo.4developments.net

Using k3d

k3d cluster delete mycluster

# to use ingress
# you have to forwards http traffic from localhost:80 to the Ingress controller
k3d cluster create mycluster \
    --api-port 6550 \
    --port "80:80@loadbalancer"   \
    --agents 2


k3d kubeconfig merge mycluster

if you need to delete old cluster config

kubectl config get-clusters
kubectl config delete-cluster CLUSTER_NAME

Some basic commands for helping debug

# to see nodes health
kubectl get nodes 

# getting first pod name (you will need to filter to be more specific)
kubectl $(kubectl get pods -ojson | jq -r '.items[0].metadata.name')

# binding ports in a pod
kubectl port-forward $(kubectl get pods -ojson | jq -r '.items[0].metadata.name') 8080:3000

# tail logs from a specific pod (the first one here)
kubectl logs -f $(kubectl get pods -ojson | jq -r '.items[0].metadata.name')

Applying a manifest for deploy a service using loadbalancer ingress in k3d

kubectl apply -f deployment.yaml