add pusher mode

caddy/Caddyfile

@@ -14,6 +14,16 @@
             websocket
         }
 
+    errors stderr
+    tls off
+}
+
+:9091 {
+    basicauth / {$ADMIN_USER} {$ADMIN_PASSWORD}
+    proxy / pushgateway:9091 {
+            transparent
+        }
+
     errors stderr
     tls off
 }

cmd/app/main.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 
-	err := app.Run()
+	err := app.RunPusher()
 
 	if err != nil {
 		log.Fatal(err)

docker-compose.yaml

@@ -75,6 +75,17 @@ services:
       - ADMIN_USER=${ADMIN_USER}
       - ADMIN_PASSWORD=${ADMIN_PASSWORD}
     restart: unless-stopped
+    networks:
+      - monitoring
+    labels:
+      org.label-schema.group: "monitoring"
+
+  pushgateway:
+    image: prom/pushgateway:v1.2.0
+    container_name: pushgateway
+    restart: unless-stopped
+    expose:
+      - 9091
     networks:
       - monitoring
     labels:

internal/app/app.go

@@ -1,12 +1,14 @@
 package app
 
 import (
+	"context"
 	"flag"
 	"fmt"
 	"log"
 	"net/http"
 	"os"
 
+	pusher "github.com/Chipazawra/v8-1c-cluster-pde/internal/Pusher"
 	"github.com/Chipazawra/v8-1c-cluster-pde/internal/rpHostsCollector"
 	"github.com/caarlos0/env"
 	rascli "github.com/khorevaa/ras-client"
@@ -69,3 +71,17 @@ func Run() error {
 
 	return nil
 }
+
+func RunPusher() error {
+
+	rcli := rascli.NewClient(fmt.Sprintf("%s:%s", conf.Host, conf.Port))
+	rcli.AuthenticateAgent(conf.User, conf.Pass)
+	log.Printf("cluster-pde connected to RAS: %v", fmt.Sprintf("%s:%s", conf.Host, conf.Port))
+	defer rcli.Close()
+
+	return pusher.New(
+		rpHostsCollector.New(rcli),
+		"pushgateway:9091",
+		pusher.WithInterval(500),
+	).Run(context.Background())
+}

internal/pusher/pusher.go

@@ -0,0 +1,82 @@
+package pusher
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/push"
+)
+
+var (
+	defaultIntervalMillis int    = 500
+	defaultJobname        string = "v8-1C-cluster-pde"
+)
+
+type Pusher struct {
+	intervalMillis int
+	collector      prometheus.Collector
+	url            string
+	jobName        string
+	pusher         *push.Pusher
+}
+
+type PusherOption func(*Pusher)
+
+func WithInterval(millis int) PusherOption {
+	return func(p *Pusher) {
+		p.intervalMillis = millis
+	}
+}
+
+func WithJobName(Name string) PusherOption {
+	return func(p *Pusher) {
+		p.jobName = Name
+	}
+}
+
+func New(collector prometheus.Collector, url string, opts ...PusherOption) *Pusher {
+
+	p := &Pusher{
+		collector:      collector,
+		intervalMillis: defaultIntervalMillis,
+		url:            url,
+		jobName:        defaultJobname,
+	}
+
+	for _, opt := range opts {
+		opt(p)
+	}
+
+	p.pusher = push.New(url, p.jobName).Collector(collector)
+
+	return p
+}
+
+func (p *Pusher) Run(ctx context.Context) error {
+
+	ticker := time.NewTicker(time.Duration(p.intervalMillis * int(time.Microsecond)))
+	done := make(chan error)
+	go func(done chan error) {
+	Loop:
+		for {
+			select {
+			case <-ticker.C:
+				err := p.pusher.Push()
+				if err != nil {
+					done <- fmt.Errorf("puser: %v", err)
+					break Loop
+				}
+			case <-ctx.Done():
+				log.Println("INFO: pusher context complete")
+				done <- nil
+				break Loop
+			}
+		}
+		close(done)
+	}(done)
+
+	return <-done
+}

prometheus/prometheus.yml

@@ -19,3 +19,9 @@ scrape_configs:
     static_configs:
       - targets: ['localhost:9090']
 
+  - job_name: 'pushgateway'
+    scrape_interval: 5s
+    honor_labels: true
+    static_configs:
+      - targets: ['pushgateway:9091']
+