simple-api-cloud

Hello World API in golang using Kubernetes and configuration for GCP

Requirements

• go (tested with go1.11.2)
• docker (tested with docker 18.03.1-ce)
• local redis instance for testing (tested with 5.0.2)
• google-cloud-sdk installed and configured with your credentials
• a working and configured Kubernetes cluster
• make

How to start

• An IP address is required on GCP for Ingress to work: gcloud compute addresses create simple-api-ip --global(replace simple-api-ip if needed)
• In file k8s/deployment.yml, replace simple-api-ip with the name you chose on line kubernetes.io/ingress.global-static-ip-name: simple-api-ip
• make ship will:
  • get dependencies
  • start tests (a local redis instance is needed to complete tests !!!)
  • build the code
  • build the docker image
  • send docker image on registry
  • launch k8s/deployment.yml on the configured Kubernetes cluster

HTTPS

Follow this guide to use Letsencrypt: https://github.com/ahmetb/gke-letsencrypt

API

• GET /: some informations on the instance

  • {"app":"simple-api-cloud","hostname":"simple-api-55f76f9647-n8pxf","version":"70ad329"}

• GET /hello/Charles: get birthday message for Charles (number of days till birthday, considering UTC)

  • normal case: {"message": "Hello Charles! Your birthday is in 300 days"}
  • when it's Charles' birthday: {"message": "Hello Charles! Happy birthday!"}
  • if Charles' birthday is unknown: {"message":"Hello! Unfortunately I don't know Charles yet. Please add his/her date of birth."}

• PUT /hello/Charles: create/update date of birth for Charles

  • req: {"dateOfBirth": "1988-12-01"} with date format YYYY-MM-DD

Deployed version on GCP

A live demo is available here:

• http://revolut-sre.franceskinj.fr
• https://revolut-sre.franceskinj.fr

TODO

• Issue with Redis: when deleting Redis pods, no connection lost events are thrown and the API never reconnects to new Redis instances..
• Use a container for building the API
• Date: a more precise date format can be used: YYYY-MM-DD hh:mm:ss. The date will be always considered UTC. If the hour is not mentioned, it will default to 00:00:00 of the given date. The date will be stored as unix timestamp.
• Spanner: more adapted with a financial context. Plus, it's all ready for scalability, availability, performance, multi-regions and totally managed. The only drawback is price...
• Stackdriver: for monitoring the whole stack
• Use Autoscaling with Custom Metrics: adapts automagically if the load goes up.
• Use Spinnaker for continuous delivery