setup.md

Setup

Get dev tools for your local machine

# Get Arkade
curl -sLS https://get.arkade.dev | sudo sh
# Get tools needed for thee lab
ark get helm
ark get k3d
ark get kubectx
# Temporarily make them available in your path
export PATH=$PATH:$HOME/.arkade/bin/

Create a Kubernetes cluster and install supporting software in the cluster

# Capture your current Kubernetes context
export CURRENT_CONTEXT=$(kubectx)
# k3s set up a cluster in docker containers!
k3d cluster create
# switch your current context to the k3d cluster
kubectx k3d-k3s-default
# Setup helm repos to get software for your Kubernetes cluster
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo add kube-state-metrics https://kubernetes.github.io/kube-state-metrics
helm repo add grafana https://grafana.github.io/helm-charts
helm repo update
# Install Prometheus, later it'll scrape metrics from the Python app's pods
helm upgrade --install metrics prometheus-community/prometheus
# Install Loki-stack, this can be used to easily look at logs
helm upgrade --install logging grafana/loki-stack \
  --namespace default --set promtail.enabled=true \
  --set grafana.enabled=true 

Build and push a container image to Docker Hub

Prior to running the script below, make sure you've altered it to point at your own account on Docker Hub. Refer to the instructions here for detail.

Note: If you decide to alter the Python app (hurray!), you'll find yourself running this script often to publish new images and test them on your Kubernetes cluster.

# this will build an image, tag it, and push it to the Docker Hub for you
./scripts/image-build.sh

Add the Python app to your Kubernetes cluster

# Allow the app's pods to use the Kubernetes API to list pods
# The code for the `running_pods` metric depends on this
kubectl apply -f ./k8s_resources/rbac.yaml
# Deploy pods which rely on the Docker image in your Docker Hub account's repo
kubectl apply -f ./k8s_resources/deployment.yaml
# Setup a related service for the deployment
kubectl apply -f ./k8s_resources/service.yaml

Test

Good job! You are now ready to test.