Birthdays

A simple application counting how many days until the birthday, built to demonstrate the best SDE/SRE practices

Try

Publicly accessible version: use SwaggerUI or curl to test the app

curl -X PUT 'https://birthdays.razum2um.me/hello/username' -H 'Content-Type: application/json' -d '{ "dateOfBirth": "2000-01-01" }'
curl 'https://birthdays.razum2um.me/hello/username'

Quick local try

Run a docker-compose in the top-level directory (using prebuilt containers) to get it locally:

docker-compose up

and open http://localhost:8000 or use curl to test the app

curl -X PUT 'http://localhost:8000/hello/username' -H 'Content-Type: application/json' -d '{ "dateOfBirth": "2000-01-01" }'
curl 'http://localhost:8000/hello/username'

Features

The app deployment adresses the following SRE aspects:

scalability: Kubernetes autoscaling based on runtime metrics (Prometheus, todo: Keda)
performance: see benchmarks in src (GET: 84k RPS; PUT: 12k RPS), todo: Grafana to draw for the deployment
redundancy: Kubernetes runs in multiple zones, CloudSQL HA setup
resilience/no-downtime production deployment: RollingUpdate strategy to rotate the pods
fault tolerance: app is able to retry database failures (e.g. during failover), it has a separate caching layer, which serves a valid cache (even is the app upstream is down)
security: ProxySQL to connect to database, the Kubernetes cluster is private, both nodes and master, using bastion host to apply
monitoring and alerting: Prometheus + Alertmanager tuned to notify developer about performance degradation, todo: Jaeger tracing
deployment process: CI/CD process using Github Actions, todo: a test runner / deployer inside the cluster, ArgoCD
rollback plan: rolling update on the previous version
documentation: using SwaggerUI, also see this repo structure and other READMEs

System diagram

Compoments

app: a web service in Rust (actix-web)
openresty: a caching layer which relies on HTTP semantics and serves from cache
memcached: distributes cache, sharded between multi-node deployment
database: HA PostgreSQL
infrastructure in GCP:
- Kubernetes (private network and master, bastion host, cert-manager, ingress-nginx)
- Cloud SQL (securely connecting via proxy sql sidecar)
- Prometeus & Alertmanager

Structure

Each layer has it's own README.md

├── src              # app code, how to run it locally
│   ├── birthdays    # web service, how to develop it locally
│   ├── nginx-cache  # caching proxy layer
├── terraform        # infrastructure, how to deploy infra in GCP
└── k8s              # cluster definitions, how to deploy app into cluster

Local development & tests

See src/README.md

razum2um/birthdays