caddy/modules/caddyhttp/reverseproxy/metrics.go

88 lines
1.9 KiB
Go

package reverseproxy
import (
"runtime/debug"
"sync"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
"go.uber.org/zap"
"go.uber.org/zap/zapcore"
)
var reverseProxyMetrics = struct {
init sync.Once
upstreamsHealthy *prometheus.GaugeVec
logger *zap.Logger
}{}
func initReverseProxyMetrics(handler *Handler) {
const ns, sub = "caddy", "reverse_proxy"
upstreamsLabels := []string{"upstream"}
reverseProxyMetrics.upstreamsHealthy = promauto.NewGaugeVec(prometheus.GaugeOpts{
Namespace: ns,
Subsystem: sub,
Name: "upstreams_healthy",
Help: "Health status of reverse proxy upstreams.",
}, upstreamsLabels)
reverseProxyMetrics.logger = handler.logger.Named("reverse_proxy.metrics")
}
type metricsUpstreamsHealthyUpdater struct {
handler *Handler
}
func newMetricsUpstreamsHealthyUpdater(handler *Handler) *metricsUpstreamsHealthyUpdater {
reverseProxyMetrics.init.Do(func() {
initReverseProxyMetrics(handler)
})
reverseProxyMetrics.upstreamsHealthy.Reset()
return &metricsUpstreamsHealthyUpdater{handler}
}
func (m *metricsUpstreamsHealthyUpdater) Init() {
go func() {
defer func() {
if err := recover(); err != nil {
if c := reverseProxyMetrics.logger.Check(zapcore.ErrorLevel, "upstreams healthy metrics updater panicked"); c != nil {
c.Write(
zap.Any("error", err),
zap.ByteString("stack", debug.Stack()),
)
}
}
}()
m.update()
ticker := time.NewTicker(10 * time.Second)
for {
select {
case <-ticker.C:
m.update()
case <-m.handler.ctx.Done():
ticker.Stop()
return
}
}
}()
}
func (m *metricsUpstreamsHealthyUpdater) update() {
for _, upstream := range m.handler.Upstreams {
labels := prometheus.Labels{"upstream": upstream.Dial}
gaugeValue := 0.0
if upstream.Healthy() {
gaugeValue = 1.0
}
reverseProxyMetrics.upstreamsHealthy.With(labels).Set(gaugeValue)
}
}