Prevent poller from dying from an error

integrations/promunifi/Gopkg.lock

@@ -103,7 +103,7 @@
   name = "golang.org/x/sys"
   packages = ["windows"]
   pruneopts = "UT"
-  revision = "ce4227a45e2eb77e5c847278dcc6a626742e2945"
+  revision = "eeba5f6aabab6d6594a9191d6bfeaca5fa6a8248"
 
 [[projects]]
   digest = "1:87738e338f505d3e3be1f80d36b53f3c4e73be9b7ad4ccae46abbe9ef04f3f71"

integrations/promunifi/pkg/poller/config.go

@@ -1,5 +1,13 @@
 package poller
 
+/*
+	I consider this file the pinacle example of how to allow a Go application to be configured from a file.
+	You can put your configuration into any file format: XML, YAML, JSON, TOML, and you can override any
+	struct member using an environment variable. The Duration type is also supported. All of the Config{}
+	and Duration{} types and methods are reusable in other projects. Just adjust the data in the struct to
+	meet your app's needs. See the New() procedure and Start() method in start.go for example usage.
+*/
+
 import (
 	"encoding/json"
 	"encoding/xml"
@@ -41,12 +49,11 @@ const ENVConfigPrefix = "UP_"
 
 // UnifiPoller contains the application startup data, and auth info for UniFi & Influx.
 type UnifiPoller struct {
-	Influx     *influxunifi.InfluxUnifi
+	Influx    *influxunifi.InfluxUnifi
-	Unifi      *unifi.Unifi
+	Unifi     *unifi.Unifi
-	Flag       *Flag
+	Flag      *Flag
-	Config     *Config
+	Config    *Config
-	errorCount int
+	LastCheck time.Time
-	LastCheck  time.Time
 }
 
 // Flag represents the CLI args available and their settings.
@@ -110,44 +117,50 @@ func (c *Config) ParseFile(configFile string) error {
 // ParseENV copies environment variables into configuration values.
 // This is useful for Docker users that find it easier to pass ENV variables
 // than a specific configuration file. Uses reflection to find struct tags.
+// This method uses the json struct tag member to match environment variables.
+// Use a custom tag name by changing "json" below, but that's overkill for this app.
 func (c *Config) ParseENV() error {
-	t := reflect.TypeOf(Config{}) // Get tag names from the Config struct.
+	t := reflect.TypeOf(*c)             // Get "types" from the Config struct.
-	// Loop each Config struct member; get reflect tag & env var value; update config.
+	for i := 0; i < t.NumField(); i++ { // Loop each Config struct member
-	for i := 0; i < t.NumField(); i++ {
 		tag := t.Field(i).Tag.Get("json")                 // Get the ENV variable name from "json" struct tag
 		tag = strings.Split(strings.ToUpper(tag), ",")[0] // Capitalize and remove ,omitempty suffix
 		env := os.Getenv(ENVConfigPrefix + tag)           // Then pull value from OS.
-		if tag == "" || env == "" {
+		if tag == "" || env == "" {                       // Skip if either are empty.
-			continue // Skip if either are empty.
+			continue
 		}
 
 		// Reflect and update the u.Config struct member at position i.
-		switch c := reflect.ValueOf(c).Elem().Field(i); c.Type().String() {
+		switch field := reflect.ValueOf(c).Elem().Field(i); field.Type().String() {
 		// Handle each member type appropriately (differently).
 		case "string":
 			// This is a reflect package method to update a struct member by index.
-			c.SetString(env)
+			field.SetString(env)
+
 		case "int":
 			val, err := strconv.Atoi(env)
 			if err != nil {
 				return fmt.Errorf("%s: %v", tag, err)
 			}
-			c.Set(reflect.ValueOf(val))
+			field.Set(reflect.ValueOf(val))
+
 		case "[]string":
-			c.Set(reflect.ValueOf(strings.Split(env, ",")))
+			field.Set(reflect.ValueOf(strings.Split(env, ",")))
+
 		case path.Base(t.PkgPath()) + ".Duration":
 			val, err := time.ParseDuration(env)
 			if err != nil {
 				return fmt.Errorf("%s: %v", tag, err)
 			}
-			c.Set(reflect.ValueOf(Duration{val}))
+			field.Set(reflect.ValueOf(Duration{val}))
+
 		case "bool":
 			val, err := strconv.ParseBool(env)
 			if err != nil {
 				return fmt.Errorf("%s: %v", tag, err)
 			}
-			c.SetBool(val)
+			field.SetBool(val)
 		}
+		// Add more types here if more types are added to the config struct.
 	}
 
 	return nil

integrations/promunifi/pkg/poller/helpers.go

@@ -8,15 +8,6 @@ import (
 
 const callDepth = 2
 
-// LogError logs an error and increments the error counter.
-// Should be used in the poller loop.
-func (u *UnifiPoller) LogError(err error, prefix string) {
-	if err != nil {
-		u.errorCount++
-		_ = log.Output(callDepth, fmt.Sprintf("[ERROR] %v: %v", prefix, err))
-	}
-}
-
 // StringInSlice returns true if a string is in a slice.
 func StringInSlice(str string, slice []string) bool {
 	for _, s := range slice {
@@ -41,7 +32,7 @@ func (u *UnifiPoller) LogDebugf(m string, v ...interface{}) {
 	}
 }
 
-// LogErrorf prints an error log entry. This is used for external library logging.
+// LogErrorf prints an error log entry.
 func (u *UnifiPoller) LogErrorf(m string, v ...interface{}) {
 	_ = log.Output(callDepth, fmt.Sprintf("[ERROR] "+m, v...))
 }

integrations/promunifi/pkg/poller/influx.go

@@ -42,7 +42,7 @@ func (u *UnifiPoller) CollectAndProcess() error {
 	u.AugmentMetrics(metrics)
 	report, err := u.Influx.ReportMetrics(metrics)
 	if err != nil {
-		u.LogError(err, "processing metrics")
+		u.LogErrorf("processing metrics: %v", err)
 		return err
 	}
 	u.LogInfluxReport(report)

integrations/promunifi/pkg/poller/prometheus.go

@@ -15,7 +15,7 @@ const oneDecimalPoint = 10
 
 // RunPrometheus starts the web server and registers the collector.
 func (u *UnifiPoller) RunPrometheus() error {
-	u.Logf("Exporting Measurements at https://%s/metrics for Prometheus", u.Config.HTTPListen)
+	u.Logf("Exporting Measurements for Prometheus at https://%s/metrics", u.Config.HTTPListen)
 	http.Handle("/metrics", promhttp.Handler())
 	prometheus.MustRegister(promunifi.NewUnifiCollector(promunifi.UnifiCollectorCnfg{
 		Namespace:    strings.Replace(u.Config.Namespace, "-", "", -1),
@@ -34,8 +34,9 @@ func (u *UnifiPoller) ExportMetrics() (*metrics.Metrics, error) {
 	if err != nil {
 		u.LogErrorf("collecting metrics: %v", err)
 		u.Logf("Re-authenticating to UniFi Controller")
+
 		if err := u.Unifi.Login(); err != nil {
-			u.LogError(err, "re-authenticating")
+			u.LogErrorf("re-authenticating: %v", err)
 			return nil, err
 		}
 

integrations/promunifi/pkg/poller/start.go

@@ -100,55 +100,36 @@ func (u *UnifiPoller) Run() error {
 
 	switch strings.ToLower(u.Config.Mode) {
 	default:
-		return u.PollController()
+		u.PollController()
+		return nil
 	case "influxlambda", "lambdainflux", "lambda_influx", "influx_lambda":
 		u.LastCheck = time.Now()
 		return u.CollectAndProcess()
+	case "both":
+		go u.PollController()
+		fallthrough
 	case "prometheus", "exporter":
 		return u.RunPrometheus()
-	case "both":
-		return u.RunBoth()
 	}
 }
 
-// RunBoth starts the prometheus exporter and influxdb exporter at the same time.
-// This will likely double the amount of polls your controller receives.
-func (u *UnifiPoller) RunBoth() error {
-	e := make(chan error)
-	defer close(e)
-	go func() {
-		e <- u.RunPrometheus()
-	}()
-	go func() {
-		e <- u.PollController()
-	}()
-	// If either method returns an error (even nil), bail out.
-	return <-e
-}
-
 // PollController runs forever, polling UniFi and pushing to InfluxDB
 // This is started by Run() or RunBoth() after everything checks out.
-func (u *UnifiPoller) PollController() error {
+func (u *UnifiPoller) PollController() {
 	interval := u.Config.Interval.Round(time.Second)
-	log.Printf("[INFO] Everything checks out! Poller started, interval: %v", interval)
+	log.Printf("[INFO] Everything checks out! Poller started, InfluxDB interval: %v", interval)
 	ticker := time.NewTicker(interval)
-	defer ticker.Stop()
-
 	for u.LastCheck = range ticker.C {
 		// Some users need to re-auth every interval because the cookie times out.
 		if u.Config.ReAuth {
 			u.LogDebugf("Re-authenticating to UniFi Controller")
 			if err := u.Unifi.Login(); err != nil {
-				return err
+				u.LogErrorf("%v", err)
+				continue
 			}
 		}
 		if err := u.CollectAndProcess(); err != nil {
-			return err
+			u.LogErrorf("%v", err)
-		}
-		// check for errors from the unifi polls.
-		if u.errorCount > 0 {
-			return fmt.Errorf("too many errors, stopping poller")
 		}
 	}
-	return nil
 }

integrations/promunifi/pkg/poller/unifi.go

@@ -67,16 +67,16 @@ func (u *UnifiPoller) CollectMetrics() (*metrics.Metrics, error) {
 	var err error
 	// Get the sites we care about.
 	m.Sites, err = u.GetFilteredSites()
-	u.LogError(err, "unifi.GetSites()")
+	u.LogErrorf("unifi.GetSites(): %v", err)
 	if u.Config.SaveIDS {
 		m.IDSList, err = u.Unifi.GetIDS(m.Sites, time.Now().Add(u.Config.Interval.Duration), time.Now())
-		u.LogError(err, "unifi.GetIDS()")
+		u.LogErrorf("unifi.GetIDS(): %v", err)
 	}
 	// Get all the points.
 	m.Clients, err = u.Unifi.GetClients(m.Sites)
-	u.LogError(err, "unifi.GetClients()")
+	u.LogErrorf("unifi.GetClients(): %v", err)
 	m.Devices, err = u.Unifi.GetDevices(m.Sites)
-	u.LogError(err, "unifi.GetDevices()")
+	u.LogErrorf("unifi.GetDevices(): %v", err)
 	return m, err
 }