Microservices: Blog

Quick start

Requirements: minikube (local Kubernetes)

1. Clone this repository
2. Start local kubernetes cluster: minikube start
3. Apply configuration files:

   cd infra/k8s
   kubectl apply -f .
   

4. Point your ingress hostname towards your minikube IP in hosts file: echo "$(echo | minikube ip)" "$(echo "blog.io")" >> /etc/hosts
5. Access to app @ http://blog.io

Services

See config.js.

Service	Port
posts	4000
comments	4001
query	4002
moderation	4003
even-bus	4005

Posts

Path	Method	Request Body	Feature	Result
/posts	POST	{ title: string}	Create a new post	201, created post object
/posts	GET	-	Get all posts	200, list of posts
/events	POST	event object	Does nothing	204

Comments

Path	Method	Request Body	Feature	Result
/posts/:id/comments	POST	{ content: string }	Create a new comment	201, comment object created
/posts/:id/comments	GET	-	Get all comments	200, list of comments
/events	POST	event object	Does nothing	204

Event bus

Path	Method	Request Body	Feature	Result
/events	POST	event = {type, data}	Echo event to other services	200

Query

Aggregates posts and comments to be able to reduce to 1 the number of requests necessary to fetch all posts & requests.

Path	Method	Request Body	Feature	Result
/events	POST	event object	Add post or comment to its local memory	200, post/comment object created
/posts	GET	-	Get all posts & comments	200, list of posts & comments

Moderation

Updates status (approved or denied) of created comments depending on wether they include the FORBIDDEN word.

Path	Method	Request Body	Feature	Result
/events	POST	COMMENT_CREATED event object	Updates status of comment and emits COMMENT_UTPDATED event	204

Architecture/Implementation

• Front end: React based
• Services: Express based (router + feature logic). No data persistence/DB. Data stored in servers' memory.
• Deployment: kubernetes

Resources

Stephen Grider udemy's course on Microservices with Node JS and React