Add Prometheus config and metric sync

cmd/icinga-kubernetes/main.go

@@ -7,18 +7,21 @@ import (
 	"github.com/icinga/icinga-kubernetes/internal"
 	"github.com/icinga/icinga-kubernetes/pkg/com"
 	"github.com/icinga/icinga-kubernetes/pkg/database"
+	"github.com/icinga/icinga-kubernetes/pkg/metrics"
 	"github.com/icinga/icinga-kubernetes/pkg/periodic"
 	schemav1 "github.com/icinga/icinga-kubernetes/pkg/schema/v1"
 	"github.com/icinga/icinga-kubernetes/pkg/sync"
 	syncv1 "github.com/icinga/icinga-kubernetes/pkg/sync/v1"
 	k8sMysql "github.com/icinga/icinga-kubernetes/schema/mysql"
+	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
 	"k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
 	kclientcmd "k8s.io/client-go/tools/clientcmd"
 	"k8s.io/klog/v2"
 	"os"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -53,7 +56,19 @@ func main() {
 	factory := informers.NewSharedInformerFactory(clientset, 0)
 	log := klog.NewKlogr()
 
-	d, err := database.FromYAMLFile(config)
+	cfg, err := config.FromYAMLFile[internal.Config](flags.Config)
+	if err != nil {
+		logging.Fatal(errors.Wrap(err, "can't create configuration"))
+	}
+
+	promClient, err := promapi.NewClient(promapi.Config{Address: cfg.Prometheus.Host + ":" + strconv.Itoa(cfg.Prometheus.Port)})
+	if err != nil {
+		logging.Fatal(errors.Wrap(err, "error creating promClient"))
+	}
+
+	promApiClient := promv1.NewAPI(promClient)
+
+	db, err := database.NewDbFromConfig(&cfg.Database, logs.GetChildLogger("Database"))
 	if err != nil {
 		klog.Fatal(err)
 	}
@@ -176,6 +191,11 @@ func main() {
 
 		return s.Run(ctx)
 	})
+	g.Go(func() error {
+		promMetricSync := metrics.NewPromMetricSync(promApiClient, db)
+
+		return promMetricSync.Run(ctx)
+	})
 
 	errs := make(chan error, 1)
 	defer close(errs)

config.example.yml

@@ -20,3 +20,12 @@ database:
 
   # Database password.
   password: CHANGEME
+
+# Configuration for Prometheus metrics API.
+prometheus:
+
+  # Prometheus host
+#  host: http://localhost
+
+    # Prometheus port
+#  port: 9090

internal/config.go

@@ -0,0 +1,25 @@
+package internal
+
+import (
+	"github.com/icinga/icinga-go-library/database"
+	"github.com/icinga/icinga-kubernetes/pkg/metrics"
+)
+
+// Config defines Icinga Kubernetes config.
+type Config struct {
+	Database   database.Config          `yaml:"database"`
+	Prometheus metrics.PrometheusConfig `yaml:"prometheus"`
+}
+
+// Validate checks constraints in the supplied configuration and returns an error if they are violated.
+func (c *Config) Validate() error {
+	if err := c.Database.Validate(); err != nil {
+		return err
+	}
+
+	if err := c.Prometheus.Validate(); err != nil {
+		return err
+	}
+
+	return nil
+}

pkg/metrics/config.go

@@ -0,0 +1,18 @@
+package metrics
+
+import "github.com/pkg/errors"
+
+// PrometheusConfig defines Prometheus configuration.
+type PrometheusConfig struct {
+	Host string `yaml:"host"`
+	Port int    `yaml:"port"`
+}
+
+// Validate checks constraints in the supplied Prometheus configuration and returns an error if they are violated.
+func (c *PrometheusConfig) Validate() error {
+	if c.Host == "" {
+		return errors.New("Prometheus host missing")
+	}
+
+	return nil
+}