Probes

Four endpoints answer "is the server alive and ready?". The unprefixed three sit at the bare host root, independent of the configured URL prefix.

Method	Path	Code	Body	Use
GET	/healthz	200	{"status":"ok"}	Kubernetes liveness probe.
GET	/readyz	200/503	{"status":"ready","datasets":N} / {"status":"not_ready","datasets":0}	Kubernetes readiness probe.
GET	/version	200	Build metadata (see below)	Manual / dashboard build identification.
GET	{prefix}/health	200	{"status":"ok"}	Legacy alias, honours prefix.

/healthz — liveness

Returns 200 immediately. The handler does no work — it answers only "is this process responsive?". Pair with a Kubernetes livenessProbe that restarts the pod if the response stops arriving.

curl -s http://localhost:8080/healthz
# {"status":"ok"}

/readyz — readiness

Returns 200 once at least one dataset is registered with the backend:

curl -s http://localhost:8080/readyz
# {"status":"ready","datasets":3}

While dataset materialisation is still in progress (or if every dataset failed to load), the same handler returns 503:

curl -i http://localhost:8080/readyz
# HTTP/1.1 503 Service Unavailable
# {"status":"not_ready","datasets":0}

Use this from a Kubernetes readinessProbe so traffic is held back until the server actually has data to serve.

/version — build metadata

curl -s http://localhost:8080/version | jq

{
  "name":       "datapress-core",
  "version":    "0.1.17",
  "backend":    "DataFusion",
  "git_sha":    "a1b2c3d4",
  "build_time": "2025-01-15T14:32:09Z",
  "profile":    "release",
  "target":     "x86_64-unknown-linux-gnu"
}

Field	Source
name	CARGO_PKG_NAME
version	CARGO_PKG_VERSION
backend	"DuckDB" / "DataFusion" / "unknown"
git_sha	DATAPRESS_GIT_SHA env var at build time (opt)
build_time	DATAPRESS_BUILD_TIME env var at build time (opt)
profile	debug / release based on cfg!(debug_assertions)
target	DATAPRESS_TARGET env var at build time (opt)

Optional fields are omitted from the JSON when not set, so the response stays compact in a no-CI dev build.

To populate the optional fields in CI:

export DATAPRESS_GIT_SHA="$(git rev-parse --short HEAD)"
export DATAPRESS_BUILD_TIME="$(date -u +%FT%TZ)"
export DATAPRESS_TARGET="$(rustc -vV | awk '/host:/ {print $2}')"
cargo build --release

Kubernetes example

livenessProbe:
  httpGet: { path: /healthz, port: http }
  periodSeconds: 10
  failureThreshold: 3

readinessProbe:
  httpGet: { path: /readyz, port: http }
  periodSeconds: 5
  failureThreshold: 2
  timeoutSeconds: 2