Files
Felis/internal/metrics/metrics_test.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

119 lines
4.0 KiB
Go

package metrics
import (
"strings"
"testing"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/testutil"
)
// wantNames is the exact set of metric names spec §23 mandates "at minimum".
// Pinning them here makes a rename a deliberate, test-visible act rather than a
// silent dashboard/alert break.
var wantNames = []string{
"felis_servers_total",
"felis_start_duration_seconds",
"felis_image_build_failures_total",
"felis_reaper_worlds_deleted_total",
}
func TestRegisterExposesNamedFelisMetrics(t *testing.T) {
reg := prometheus.NewRegistry()
if err := Register(reg); err != nil {
t.Fatalf("Register: %v", err)
}
// Record into each collector through its typed API so a Gather emits the
// family — this proves the exported vars are the ones actually registered,
// not shadow copies.
ServersTotal.WithLabelValues("Running").Set(3)
StartDurationSeconds.Observe(12.5)
ImageBuildFailuresTotal.Inc()
ReaperWorldsDeletedTotal.Add(2)
mfs, err := reg.Gather()
if err != nil {
t.Fatalf("Gather: %v", err)
}
got := map[string]bool{}
for _, mf := range mfs {
got[mf.GetName()] = true
}
for _, name := range wantNames {
if !got[name] {
t.Errorf("mandated metric %q not exposed by the registry", name)
}
}
// Nothing may leak out from under the felis_ namespace — a stray name would
// mean a collector was declared without the namespace prefix.
for name := range got {
if !strings.HasPrefix(name, "felis_") {
t.Errorf("metric %q is not under the felis_ namespace", name)
}
}
}
func TestSyncServerGaugeResetsStaleStates(t *testing.T) {
// Self-contained (Reset->sync->assert within this one test) so it never
// clobbers another test's ServersTotal children. The correctness point is the
// Reset inside SyncServerGauge: a state present in one snapshot but absent from
// the next must drain to 0, not retain its stale last value forever.
SyncServerGauge([]string{"Running", "Running", "Stopped"})
if got := testutil.ToFloat64(ServersTotal.WithLabelValues("Running")); got != 2 {
t.Errorf("Running = %v, want 2", got)
}
if got := testutil.ToFloat64(ServersTotal.WithLabelValues("Stopped")); got != 1 {
t.Errorf("Stopped = %v, want 1", got)
}
// Next snapshot: the two Running servers are gone. Without the Reset the gauge
// would still report Running=2; with it, the child drains to 0.
SyncServerGauge([]string{"Stopped"})
if got := testutil.ToFloat64(ServersTotal.WithLabelValues("Running")); got != 0 {
t.Errorf("Running after drain = %v, want 0", got)
}
if got := testutil.ToFloat64(ServersTotal.WithLabelValues("Stopped")); got != 1 {
t.Errorf("Stopped = %v, want 1", got)
}
}
func TestRegisterIsIdempotent(t *testing.T) {
reg := prometheus.NewRegistry()
if err := Register(reg); err != nil {
t.Fatalf("first Register: %v", err)
}
// A second Register into the same registry must not error: setup that runs
// twice (manager restart, test re-entry) should be harmless, not fatal.
if err := Register(reg); err != nil {
t.Fatalf("second Register should be idempotent, got: %v", err)
}
}
func TestCountersRecordExpectedValues(t *testing.T) {
// These collectors are package-level singletons. This test asserts on a
// gauge child labelled "Stopped" (no other test touches it) and a >=1 bound
// on the build-failure counter, so values stay stable regardless of test
// ordering or accumulation across the binary.
reg := prometheus.NewRegistry()
if err := Register(reg); err != nil {
t.Fatalf("Register: %v", err)
}
ImageBuildFailuresTotal.Inc()
if got := testutil.ToFloat64(ImageBuildFailuresTotal); got < 1 {
t.Errorf("image build failures = %v, want >= 1", got)
}
g := ServersTotal.WithLabelValues("Stopped")
g.Set(7)
if got := testutil.ToFloat64(g); got != 7 {
t.Errorf("servers_total{state=Stopped} = %v, want 7", got)
}
StartDurationSeconds.Observe(30)
if n := testutil.CollectAndCount(StartDurationSeconds); n != 1 {
t.Errorf("start_duration_seconds collected %d metrics, want 1 histogram", n)
}
}