etcd

Overview ¶

Example: etcd provider.

Models the runtime config of a checkout service: log level, request timeout, a rate limit, a maintenance feature flag, a database connection struct, and a list of allowed CORS origins. etcd watches every key under "checkout/" with a single prefix watch, so updates arrive as events.

Run it end to end:

docker compose up -d
docker compose exec etcd etcdctl put checkout/log_level info
docker compose exec etcd etcdctl put checkout/request_timeout 30s
docker compose exec etcd etcdctl put checkout/rate_limit_rps 100
docker compose exec etcd etcdctl put checkout/maintenance_mode false
docker compose exec etcd etcdctl put checkout/database '{"host":"db.internal","port":5432,"max_open_conns":20}'
docker compose exec etcd etcdctl put checkout/allowed_origins '["https://app.example.com"]'
go run main.go

Then change a value and watch the app log the event:

docker compose exec etcd etcdctl put checkout/rate_limit_rps 500
docker compose exec etcd etcdctl put checkout/maintenance_mode true