A Rust Kubernetes operator for PostgreSQL database management, with observability instrumentation. This operator concerns itself with managing databases and user grants to databases only; it is not aiming at being the next SchemaHero or postgres-operator.
The Controller object reconciles DatabaseServer and Database instances when changes to them are detected, and
optionally creates and deletes databases in the referenced servers.
Apply the CRD from cached file, or pipe it from crdgen to pickup schema changes:
cargo run --bin crdgen | kubectl apply -f -Install the controller via helm by setting your preferred settings. For defaults:
helm template charts/db-operator | kubectl apply -f -
kubectl wait --for=condition=available deploy/db-operator --timeout=30s
kubectl port-forward service/db-operator 8080:80Build and run with telemetry feature, or configure it via helm:
helm template charts/db-operator --set tracing.enabled=true | kubectl apply -f -This requires an OpenTelemetry collector in your
cluster. Tempo / opentelemetry-operator / grafana agent
should all work out of the box. If your collector does not support grpc otlp you need to change the exporter in
telemetry.rs.
Note that
the images are pushed either with or without the telemetry feature
depending on whether the tag includes otel.
Metrics is available on /metrics and a ServiceMonitor is configurable from the chart:
helm template charts/db-operator --set serviceMonitor.enabled=true | kubectl apply -f -cargo runor, with optional telemetry:
OPENTELEMETRY_ENDPOINT_URL=https://0.0.0.0:55680 RUST_LOG=info,kube=trace,controller=debug cargo run --features=telemetryFor prebuilt, edit the chart values or snapshotted yaml and apply as you see fit (like above).
To develop by building and deploying the image quickly, we recommend using tilt, via tilt up
instead.
In either of the run scenarios, your app is listening on port 8080, and it will observe Document events.
Try some of:
kubectl apply -f yaml/instance-lorem.yaml
kubectl delete doc lorem
kubectl edit doc lorem # change hiddenThe reconciler will run and write the status object on every change. You should see results in the logs of the pod, or
on the .status object outputs of kubectl get doc -oyaml.
The sample web server exposes some example metrics and debug information you can inspect with curl.
$ kubectl apply -f yaml/instance-lorem.yaml
$ curl 0.0.0.0:8080/metrics
# HELP db_controller_reconcile_duration_seconds The duration of reconcile to complete in seconds
# TYPE db_controller_reconcile_duration_seconds histogram
db_controller_reconcile_duration_seconds_bucket{le="0.01"} 1
db_controller_reconcile_duration_seconds_bucket{le="0.1"} 1
db_controller_reconcile_duration_seconds_bucket{le="0.25"} 1
db_controller_reconcile_duration_seconds_bucket{le="0.5"} 1
db_controller_reconcile_duration_seconds_bucket{le="1"} 1
db_controller_reconcile_duration_seconds_bucket{le="5"} 1
db_controller_reconcile_duration_seconds_bucket{le="15"} 1
db_controller_reconcile_duration_seconds_bucket{le="60"} 1
db_controller_reconcile_duration_seconds_bucket{le="+Inf"} 1
db_controller_reconcile_duration_seconds_sum 0.013
db_controller_reconcile_duration_seconds_count 1
# HELP db_controller_reconciliation_errors_total reconciliation errors
# TYPE db_controller_reconciliation_errors_total counter
db_controller_reconciliation_errors_total 0
# HELP db_controller_reconciliations_total reconciliations
# TYPE db_controller_reconciliations_total counter
db_controller_reconciliations_total 1
$ curl 0.0.0.0:8080/
{"last_event":"2019-07-17T22:31:37.591320068Z"}The metrics will be scraped by prometheus if you setup aServiceMonitor for it.
The example reconciler only checks the .spec.hidden bool. If it does, it updates the .status object to reflect
whether the instance is_hidden. It also sends a Kubernetes event associated with the controller. It is visible
at the bottom of kubectl describe doc samuel.
To extend this controller for a real-world setting. Consider looking at the kube.rs controller guide.
Install:
sudo snap install microk8s --classic && \
sudo microk8s.enable dns && \
sudo microk8s.enable registryFetch the configuration and merge it into your .kube/config file.
sudo microk8s.kubectl config view --flattenYou can use kubectx to switch the contexts quickly.
Use ctlptl and kind to create a cluster:
ctlptl create registry ctlptl-registry --port=5005
ctlptl create cluster kind --registry=ctlptl-registry --name=kind-db-operator