Project design
- Docker & Kubernetes course
- Intermediate
- Lesson 67/82
- 4 min
Design the Kubernetes structure for web and database.
Project: a multi-tier application
In this project you'll move an application made of a web front end, an API and a PostgreSQL database to Kubernetes. The plan:
- Its own
magazanamespace - Database: a single-replica Deployment taking its password from a Secret + a ClusterIP Service
- API and web: multi-replica Deployments, settings from a ConfigMap
- Only web is exposed outside (NodePort)
k8s/
00-namespace.yaml
10-db.yaml
20-api.yaml
30-web.yaml
40-ayar.yaml
kubectl apply -f k8s/The numbers in the file names keep the order predictable when the folder is applied.
Namespace and context
The first file creates the namespace; all later objects carry metadata.namespace: magaza. While working, the context's namespace is set to avoid writing -n on every command:
# 00-namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
name: magaza
kubectl apply -f k8s/00-namespace.yaml
kubectl config set-context --current --namespace=magazaPractice Prepare the namespace
Write two commands: create the magaza namespace; set the active context's namespace to magaza.
Starter code
# buraya yazSample solution
kubectl create namespace magaza
kubectl config set-context --current --namespace=magazaExpected output
namespace/magaza created Context "minikube" modified.
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 In this design, can the database be reached from outside the cluster?
- Yes, through port 5432
- Yes, via NodePort
- Only in Minikube
- No; ClusterIP is cluster-internal only Correct answer
Explanation: When needed, temporary access is given with kubectl port-forward.
2 Apply all files in the folder.
Question
kubectl apply -f ____
Answer
kubectl apply -f k8s/Explanation: -f can take a folder.
3 Match the tiers.
| Term | Meaning |
|---|---|
web |
Exposed with NodePort |
api |
ClusterIP, many replicas |
db |
ClusterIP, single replica |
magaza |
The project's namespace |