README
¶
Deferred-init lifecycle
Demonstrates serving /healthz immediately while a long-running bootstrap
(warmCaches) runs in the background. Application routes return 503 Service
Unavailable until both the deferred init and the OnReady hook succeed; then
the server flips to ready and traffic flows.
The pattern is for processes that need to register with an orchestrator (k8s readiness, ALB target health, etc.) before they finish their slow startup work — warming a cache, opening a long-lived database connection, fetching config from a remote secret store.
Run
go run ./examples/deferred-init &
In another shell:
curl -i http://localhost:8080/healthz # 200 immediately
curl -i http://localhost:8080/api/users # 503 until ready (~3s), then 200
The 503 is the contract — your orchestrator probes /healthz for liveness
and /api/... for traffic readiness. Don't probe traffic routes with
liveness intervals.
Documentation
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Overview ¶
Deferred-init example.
Demonstrates serving /healthz immediately while long-running bootstrap work (warmCaches) runs in the background. Application routes return 503 until bootstrap and the OnReady hook both succeed, then the server flips to ready.
Run it:
go run examples/deferred-init/main.go
Then in another shell:
curl -i http://localhost:8080/healthz # 200 immediately curl -i http://localhost:8080/api/users # 503 until ready (~3s), then 200
Source Files