This commit is contained in:
Nate Brown
2026-05-07 23:36:21 -05:00
parent 1e36ab8b3a
commit 3a21ecd6c1

View File

@@ -1,3 +1,5 @@
//go:build linux || darwin
package nebula
import (
@@ -13,12 +15,13 @@ import (
"github.com/slackhq/nebula/test"
"github.com/slackhq/nebula/udp"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
// Test_emitStats_primesGauges verifies issue #907: certificate gauges should
// not read 0 between goroutine launch and the first ticker fire. The ticker
// interval here is set far longer than the test runtime so that any non-zero
// reading must come from the synchronous prime call, not a tick.
// Test_emitStats_primesGauges covers issue #907: a Prometheus scrape that
// landed before the first ticker fire used to read 0 for the cert gauges.
// emitStats now primes the gauges before entering the ticker loop. We assert
// the gauge is zero before the first call and non-zero after.
func Test_emitStats_primesGauges(t *testing.T) {
defer metrics.DefaultRegistry.UnregisterAll()
@@ -45,29 +48,26 @@ func Test_emitStats_primesGauges(t *testing.T) {
pki: &PKI{},
handshakeManager: NewHandshakeManager(l, hostMap, lh, &udp.NoopConn{}, defaultHandshakeConfig),
l: l,
// On linux, udp.NewUDPStatsEmitter indexes writers[0] and asserts to
// *udp.StdConn. A zero value works: getMemInfo sees a nil rawConn,
// returns an error, and the emitter falls through to a no-op.
writers: []udp.Conn{&udp.StdConn{}},
}
ifce.pki.cs.Store(cs)
ttlGauge := metrics.GetOrRegisterGauge("certificate.ttl_seconds", nil)
require.Zero(t, ttlGauge.Value(), "gauge should be zero before emitStats runs")
// Pre-cancel the context so emitStats returns after priming the gauges
// without ever reading from ticker.C. The one hour interval is just a
// belt-and-suspenders, the test does not expect the ticker to fire.
ctx, cancel := context.WithCancel(context.Background())
done := make(chan struct{})
go func() {
ifce.emitStats(ctx, time.Hour) // ticker interval that will never fire
close(done)
}()
cancel()
ifce.emitStats(ctx, time.Hour)
// Give the goroutine a beat to run the synchronous prime call. This is
// generous: emit() is microseconds of work in practice.
assert.Eventually(t, func() bool {
return metrics.GetOrRegisterGauge("certificate.ttl_seconds", nil).Value() > 0
}, time.Second, 10*time.Millisecond, "certificate.ttl_seconds should be primed before first tick")
ttl := metrics.GetOrRegisterGauge("certificate.ttl_seconds", nil).Value()
assert.Positive(t, ttl, int64(0))
ttl := ttlGauge.Value()
assert.Positive(t, ttl, "ttl gauge should be primed by emitStats before its first tick")
assert.LessOrEqual(t, ttl, int64(3600))
assert.Equal(t, int64(cert.Version1), metrics.GetOrRegisterGauge("certificate.initiating_version", nil).Value())
assert.Equal(t, int64(cert.Version1), metrics.GetOrRegisterGauge("certificate.max_version", nil).Value())
cancel()
<-done
}