support environment variables as configuration source

README.md

@@ -37,5 +37,3 @@ You can generate nice dashboards in Grafana, based on your data in Prometheus. A
 * Pipeline validation
 * Testing this with real application databases
 * Support for other metric types than gauges
-* Dockerfile
-* Automated DockerHub build and publishing

go.mod

@@ -3,6 +3,7 @@ module mongodb-query-exporter
 go 1.13
 
 require (
+	github.com/namsral/flag v1.7.4-pre
 	github.com/prometheus/client_golang v1.6.0
 	github.com/remeh/sizedwaitgroup v1.0.0
 	go.mongodb.org/mongo-driver v1.3.3

go.sum

@@ -88,6 +88,8 @@ github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lN
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/montanaflynn/stats v0.0.0-20171201202039-1bf9dbcd8cbe/go.mod h1:wL8QJuTMNUDYhXwkmfOly8iTdp5TEcJFWZD2D7SIkUc=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
+github.com/namsral/flag v1.7.4-pre h1:b2ScHhoCUkbsq0d2C15Mv+VU8bl8hAXV8arnWiOHNZs=
+github.com/namsral/flag v1.7.4-pre/go.mod h1:OXldTctbM6SWH1K899kPZcf65KxJiD7MsceFUpB5yDo=
 github.com/pelletier/go-toml v1.4.0/go.mod h1:PN7xzY2wHTK0K9p34ErDQMlFxa51Fk0OUruD3k1mMwo=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=

main.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"context"
-	"flag"
+	"github.com/namsral/flag"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"go.mongodb.org/mongo-driver/mongo"