package metrics import ( "context" "net/http" "github.com/prometheus/client_golang/prometheus/promhttp" log "github.com/sirupsen/logrus" ) // Service serves metrics provided by prometheus. type Service struct { *http.Server config PrometheusConfig } // PrometheusConfig config for Prometheus used for monitoring. // Additional information about Prometheus could be found here: https://prometheus.io/docs/guides/go-application. type PrometheusConfig struct { Enabled bool `yaml:"Enabled"` Port string `yaml:"Port"` } // NewMetricsService created new service for gathering metrics. func NewMetricsService(cfg PrometheusConfig) *Service { return &Service{ &http.Server{ Addr: ":" + cfg.Port, Handler: promhttp.Handler(), }, cfg, } } // Start runs http service with exposed `/metrics` endpoint on configured port. func (ms *Service) Start() { if ms.config.Enabled { err := ms.ListenAndServe() if err != nil { log.WithFields(log.Fields{ "endpoint": ms.Addr, }).Info("metrics service up and running") } else { log.Warn("metrics service couldn't start on configured port") } } else { log.Infof("metrics service hasn't started since it's disabled") } } // ShutDown stops service. func (ms *Service) ShutDown() { log.WithFields(log.Fields{ "endpoint": ms.config.Port, }).Info("shutting down monitoring-service") err := ms.Shutdown(context.Background()) if err != nil { log.Fatal("can't shut down monitoring service") } }