Allow environment variable configuration

integrations/inputunifi/unifipoller/config.go

@@ -22,6 +22,27 @@ const (
 	defaultUnifURL  = "https://127.0.0.1:8443"
 )
 
+// These are environment variables that can be used to override configuration.
+// Useful for Docker users.
+const (
+	ENVConfigMode       = "UP_POLLING_MODE"
+	ENVConfigInfluxDB   = "UP_INFLUX_DB"
+	ENVConfigInfluxUser = "UP_INFLUX_USER"
+	ENVConfigInfluxPass = "UP_INFLUX_PASS"
+	ENVConfigInfluxURL  = "UP_INFLUX_URL"
+	ENVConfigUnifiUser  = "UP_UNIFI_USER"
+	ENVConfigUnifiPass  = "UP_UNIFI_PASS"
+	ENVConfigUnifiBase  = "UP_UNIFI_URL"
+	ENVConfigReAuth     = "UP_REAUTHENTICATE"
+	ENVConfigVerifySSL  = "UP_VERIFY_SSL"
+	ENVConfigCollectIDS = "UP_COLLECT_IDS"
+	ENVConfigQuiet      = "UP_QUIET_MODE"
+	ENVConfigDebug      = "UP_DEBUG_MODE"
+	ENVConfigInterval   = "UP_POLLING_INTERVAL"
+	ENVConfigMaxErrors  = "UP_MAX_ERRORS"
+	ENVConfigSites      = "UP_POLL_SITES"
+)
+
 // UnifiPoller contains the application startup data, and auth info for UniFi & Influx.
 type UnifiPoller struct {
 	Influx     influx.Client

integrations/inputunifi/unifipoller/dumper.go

@@ -20,7 +20,8 @@ func (u *UnifiPoller) DumpJSONPayload() (err error) {
 	if err != nil {
 		return err
 	}
-	fmt.Fprintln(os.Stderr, "[INFO] Authenticated to UniFi Controller @", u.Config.UnifiBase, "as user", u.Config.UnifiUser)
+	fmt.Fprintf(os.Stderr, "[INFO] Authenticated to UniFi Controller @ %v as user %v",
+		u.Config.UnifiBase, u.Config.UnifiUser)
 	if err := u.CheckSites(); err != nil {
 		return err
 	}
@@ -46,7 +47,8 @@ func (u *UnifiPoller) DumpJSONPayload() (err error) {
 func (u *UnifiPoller) dumpSitesJSON(path, name string, sites unifi.Sites) error {
 	for _, s := range sites {
 		apiPath := fmt.Sprintf(path, s.Name)
-		_, _ = fmt.Fprintf(os.Stderr, "[INFO] Dumping %s: '%s' JSON for site: %s (%s):\n", name, apiPath, s.Desc, s.Name)
+		_, _ = fmt.Fprintf(os.Stderr, "[INFO] Dumping %s: '%s' JSON for site: %s (%s):\n",
+			name, apiPath, s.Desc, s.Name)
 		if err := u.PrintRawAPIJSON(apiPath); err != nil {
 			return err
 		}

integrations/inputunifi/unifipoller/helpers.go

@@ -43,3 +43,26 @@ func (u *UnifiPoller) LogDebugf(m string, v ...interface{}) {
 func (u *UnifiPoller) LogErrorf(m string, v ...interface{}) {
 	_ = log.Output(2, fmt.Sprintf("[ERROR] "+m, v...))
 }
+
+// pick returns the first non empty string in a list.
+// used in a few places around this library.
+func pick(strings ...string) string {
+	for _, s := range strings {
+		if s != "" {
+			return s
+		}
+	}
+	return ""
+}
+
+// parseBool returns true/false if the string is "true" or "false", otherwise returns e value.
+func parseBool(s string, e bool) bool {
+	switch s {
+	case "true", "t":
+		return true
+	case "false", "f":
+		return false
+	default:
+		return e
+	}
+}

integrations/inputunifi/unifipoller/start.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"strconv"
 	"strings"
 	"time"
 
@@ -48,6 +49,34 @@ func (f *Flag) Parse(args []string) {
 	_ = f.FlagSet.Parse(args)
 }
 
+// setEnvVarOptions copies environment variables into configuration values.
+// This is useful for Docker users that find it easier to pass ENV variables
+// that a specific configuration file.
+func (u *UnifiPoller) setEnvVarOptions() {
+	u.Config.Mode = pick(os.Getenv(ENVConfigMode), u.Config.Mode)
+	u.Config.InfluxDB = pick(os.Getenv(ENVConfigInfluxDB), u.Config.InfluxDB)
+	u.Config.InfluxUser = pick(os.Getenv(ENVConfigInfluxUser), u.Config.InfluxUser)
+	u.Config.InfluxPass = pick(os.Getenv(ENVConfigInfluxPass), u.Config.InfluxPass)
+	u.Config.InfluxURL = pick(os.Getenv(ENVConfigInfluxURL), u.Config.InfluxURL)
+	u.Config.UnifiUser = pick(os.Getenv(ENVConfigUnifiUser), u.Config.UnifiUser)
+	u.Config.UnifiPass = pick(os.Getenv(ENVConfigUnifiPass), u.Config.UnifiPass)
+	u.Config.UnifiBase = pick(os.Getenv(ENVConfigUnifiBase), u.Config.UnifiBase)
+	u.Config.ReAuth = parseBool(os.Getenv(ENVConfigReAuth), u.Config.ReAuth)
+	u.Config.VerifySSL = parseBool(os.Getenv(ENVConfigVerifySSL), u.Config.VerifySSL)
+	u.Config.CollectIDS = parseBool(os.Getenv(ENVConfigCollectIDS), u.Config.CollectIDS)
+	u.Config.Quiet = parseBool(os.Getenv(ENVConfigQuiet), u.Config.Quiet)
+	u.Config.Debug = parseBool(os.Getenv(ENVConfigDebug), u.Config.Debug)
+	if e := os.Getenv(ENVConfigInterval); e != "" {
+		_ = u.Config.Interval.UnmarshalText([]byte(e))
+	}
+	if e := os.Getenv(ENVConfigMaxErrors); e != "" {
+		u.Config.MaxErrors, _ = strconv.Atoi(e)
+	}
+	if e := os.Getenv(ENVConfigSites); e != "" {
+		u.Config.Sites = strings.Split(e, ",")
+	}
+}
+
 // GetConfig parses and returns our configuration data.
 func (u *UnifiPoller) GetConfig() error {
 	// Preload our defaults.
@@ -57,13 +86,14 @@ func (u *UnifiPoller) GetConfig() error {
 		InfluxPass: defaultInfxPass,
 		InfluxDB:   defaultInfxDb,
 		UnifiUser:  defaultUnifUser,
-		UnifiPass:  os.Getenv("UNIFI_PASSWORD"),
+		UnifiPass:  os.Getenv("UNIFI_PASSWORD"), // deprecated name.
 		UnifiBase:  defaultUnifURL,
 		Interval:   Duration{defaultInterval},
 		Sites:      []string{"default"},
-		Quiet:      u.Flag.DumpJSON != "",
+		Quiet:      u.Flag.DumpJSON != "", //s uppress the following u.Logf line.
 	}
 	u.Logf("Loading Configuration File: %s", u.Flag.ConfigFile)
+	defer u.setEnvVarOptions() // Set env variable overrides when done here.
 	switch buf, err := ioutil.ReadFile(u.Flag.ConfigFile); {
 	case err != nil:
 		return err