Files
Felis/cmd/felis/operator.go
T
flyemoji 79eae7f669 feat(metrics): publish felis_servers_total from a fleet snapshot
A per-object reconcile cannot maintain felis_servers_total (spec §23): it
sees one server per call, so it could never Set a correct fleet-wide gauge
and inc/dec on transitions would drift on any missed event. Add a snapshot
producer instead.

metrics.SyncServerGauge Resets the GaugeVec then Sets one child per state,
so a state that drains to zero reports 0 rather than a stale last value.
operator.GaugeSyncer is a manager.Runnable that periodically Lists the
fleet and republishes from it, defaulting an unset desiredState to Stopped.

SyncOnce is exercised end-to-end against a fake client (List, default,
republish); the ticker loop in Start is the only untested I/O edge.
2026-06-30 12:52:53 +09:00

97 lines
4.0 KiB
Go

package main
import (
"flag"
"fmt"
"io"
"felis.lolicon.best/internal/apis/felis/v1alpha1"
felismetrics "felis.lolicon.best/internal/metrics"
"felis.lolicon.best/internal/operator"
"k8s.io/apimachinery/pkg/runtime"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
clientgoscheme "k8s.io/client-go/kubernetes/scheme"
ctrl "sigs.k8s.io/controller-runtime"
"sigs.k8s.io/controller-runtime/pkg/cache"
ctrlmetrics "sigs.k8s.io/controller-runtime/pkg/metrics"
metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
)
// cmdOperator runs the MinecraftServer controller-manager (spec §5). It builds
// the scheme, wires the Reconciler with the production RCON prober, and blocks
// on the manager until the process receives a termination signal.
func cmdOperator(args []string, _, stderr io.Writer) int {
fs := flag.NewFlagSet("operator", flag.ContinueOnError)
fs.SetOutput(stderr)
metricsAddr := fs.String("metrics-bind-address", ":8080", "address the metric endpoint binds to")
// namespace MUST equal the [k8s] namespace felis-api is configured with, and
// the deployment manifests (felis manifests) render both from one value. It
// scopes the manager's cache (informers) to a single namespace so the operator
// can run under a namespaced Role instead of cluster-admin (spec §21). The
// default matches config.defaultNamespace, so an unconfigured deployment
// agrees; a mismatch would silently scope the cache to the wrong namespace and
// every reconcile would see zero servers — hence the watched namespace is
// logged at startup so a divergence surfaces immediately rather than silently.
namespace := fs.String("namespace", "minecraft", "namespace to watch; must match felis-api's [k8s] namespace")
if err := fs.Parse(args); err != nil {
return 2
}
scheme := runtime.NewScheme()
utilruntime.Must(clientgoscheme.AddToScheme(scheme))
utilruntime.Must(v1alpha1.AddToScheme(scheme))
mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
Scheme: scheme,
Metrics: metricsserver.Options{BindAddress: *metricsAddr},
// Scope every informer to the single watched namespace. Without this the
// cached client (mgr.GetClient) would LIST/WATCH cluster-wide, which a
// namespaced Role cannot grant — the operator would fail closed at runtime
// or, worse, demand cluster-admin. With it, the platform.OperatorRole
// (get/list/watch in one namespace) is exactly sufficient.
Cache: cache.Options{
DefaultNamespaces: map[string]cache.Config{*namespace: {}},
},
})
if err != nil {
fmt.Fprintf(stderr, "felis operator: create manager: %v\n", err)
return 1
}
fmt.Fprintf(stderr, "felis operator: watching namespace %q\n", *namespace)
// Publish the named felis_* metrics (spec §23) on the endpoint the manager
// already serves (metricsAddr). controller-runtime's metrics server exposes
// its global Registry, so registering into it is all that is needed for
// /metrics to carry felis_servers_total and friends. Register is idempotent,
// so an in-process restart never double-registers fatally.
if err := felismetrics.Register(ctrlmetrics.Registry); err != nil {
fmt.Fprintf(stderr, "felis operator: register metrics: %v\n", err)
return 1
}
r := &operator.Reconciler{
Client: mgr.GetClient(),
Scheme: mgr.GetScheme(),
Prober: operator.RconProber{},
}
if err := r.SetupWithManager(mgr); err != nil {
fmt.Fprintf(stderr, "felis operator: setup controller: %v\n", err)
return 1
}
// Republish felis_servers_total from a periodic full List of the fleet. A
// per-object reconcile can never maintain a fleet-wide gauge correctly, so a
// snapshot Runnable owns it; it shares the manager's cached client and stops
// with the manager.
if err := mgr.Add(&operator.GaugeSyncer{Client: mgr.GetClient()}); err != nil {
fmt.Fprintf(stderr, "felis operator: add gauge syncer: %v\n", err)
return 1
}
if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
fmt.Fprintf(stderr, "felis operator: manager exited: %v\n", err)
return 1
}
return 0
}