switch to using config file (#1)

* remove flags, only support config file
* update vendored modules

Given we need to pass a password, don't expose it on the command line or in the environment.

.gitignore

@@ -1 +1 @@
-netgear_cm_exporter
+/netgear_cm_exporter

.promu.yml

@@ -5,7 +5,6 @@ build:
         - name: netgear_cm_exporter
     flags: -mod=vendor -a
     ldflags: |
-        -X main.buildInfo.Version={{.Version}}
         -X main.version={{.Version}}
         -X main.revision={{.Revision}}
         -X main.branch={{.Branch}}

README.md

@@ -21,58 +21,20 @@ go get github.com/ickymettle/netgear_cm_exporter
 ## Usage
 
 ```
-Usage of netgear_cm_exporter:
+Usage of ./netgear_cm_exporter:
   -config.file string
-    	Path to configuration file. (optional)
-  -modem.address string
-    	Cable modem admin administrative ip address and port. (default "192.168.100.1")
-  -modem.password string
-    	Modem admin password.
-  -modem.username string
-    	Modem admin username. (default "admin")
-  -telemetry.addr string
-    	Listen address for metrics endpoint. (default "localhost:9527")
-  -telemetry.path string
-    	Path to metric exposition endpoint. (default "/metrics")
+    	Path to configuration file. (default "netgear_cm_exporter.yml")
+  -version
+    	Print version information.
 ```
 
-The minimal set of command line flags are the IP address of your cable modem, and the admin password. This
-exporter supports a few different means of setting configuration options, you can chose what works best for your environment.
-
-### Configuring via command line flags
-
-```
-./netgear_cm_exporter -modem.address 10.0.0.1 -modem.username admin -modem.password foobaz
-```
-
-### Configuring via environment variables
-
-Each command line flag can be set in the environment by prefixing the flag with `NETGEAR_CM_EXPORTER` and
-providing the command line flag name in uppercase.
-
-eg.
-
-```
-export NETGEAR_CM_EXPORTER_MODEM_ADDRESS=10.0.0.1
-export NETGEAR_CM_EXPORTER_MODEM_USERNAME=admin
-export NETGEAR_CM_EXPORTER_MODEM_PASSWORD=foobaz
-```
-
-### Configuring via config file
-
-Lastly if you prefer you can write a config file with each option listed per line in key value pairs delimited by
-spaces.
-
-eg. create a file `netgear_cm_exporter.conf` with the following contents:
-
-```
-modem.address 10.0.0.1
-modem.username admin
-modem.password foobaz
-```
+An example configuration file is provided in `example_config.yml` showing all the possible
+configuration options. The values in the example are the defaults, the bare minimum configuration
+is the administrative password to your modem:
 
 ```
-./netgear_exporter -config.file netgear_cm_exporter.conf
+modem:
+  password: <your password here>
 ```
 
 ## Grafana Dashboard

config.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	"github.com/pkg/errors"
+	yaml "gopkg.in/yaml.v2"
+)
+
+type Modem struct {
+	Address  string `yaml:"address"`
+	Username string `yaml:"username"`
+	Password string `yaml:"password"`
+}
+
+type Telemetry struct {
+	ListenAddress string `yaml:"listen_address"`
+	MetricsPath   string `yaml:"metrics_path"`
+}
+
+type Config struct {
+	Modem     Modem     `yaml:"modem"`
+	Telemetry Telemetry `yaml:"telemetry"`
+}
+
+func NewConfigFromFile(path string) (*Config, error) {
+	content, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to read config file")
+	}
+
+	// Setup default config.
+	config := Config{
+		Modem: Modem{
+			Address:  "192.168.100.1",
+			Username: "admin",
+		},
+		Telemetry: Telemetry{
+			ListenAddress: ":9527",
+			MetricsPath:   "/metrics",
+		},
+	}
+
+	if err := yaml.Unmarshal(content, &config); err != nil {
+		return nil, errors.Wrap(err, "unable to parse config YAML")
+	}
+
+	if config.Modem.Password == "" {
+		return nil, fmt.Errorf("modem password isn't set in config")
+	}
+
+	return &config, nil
+}

config_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestNewConfigFromFile(t *testing.T) {
+	want := &Config{
+		Modem: Modem{
+			Address:  "192.168.100.1",
+			Username: "admin",
+			Password: "foobaz",
+		},
+		Telemetry: Telemetry{
+			ListenAddress: ":9527",
+			MetricsPath:   "/metrics",
+		},
+	}
+
+	got, err := NewConfigFromFile("testdata/minimal.yml")
+	if err != nil {
+		t.Error(err)
+	}
+
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("config differs (-want, +got): %s", diff)
+	}
+
+}

example_config.yml

@@ -0,0 +1,8 @@
+modem:
+  address: 192.168.100.1
+  username: admin
+  password: yourpassword
+
+telemetry:
+  listen_address: 127.0.0.1:9527
+  metrics_path: /metrics

go.mod

@@ -7,10 +7,13 @@ require (
 	github.com/antchfx/xpath v0.0.0-20181208024549-4bbdf6db12aa // indirect
 	github.com/gobwas/glob v0.2.3 // indirect
 	github.com/gocolly/colly v1.1.0
+	github.com/google/go-cmp v0.2.0
 	github.com/kennygrant/sanitize v1.2.4 // indirect
-	github.com/peterbourgon/ff v1.0.3
+	github.com/peterbourgon/ff v1.0.3 // indirect
+	github.com/pkg/errors v0.8.0
 	github.com/prometheus/client_golang v0.9.2
 	github.com/saintfish/chardet v0.0.0-20120816061221-3af4cd4741ca // indirect
 	github.com/temoto/robotstxt v0.0.0-20180810133444-97ee4a9ee6ea // indirect
 	google.golang.org/appengine v1.4.0 // indirect
+	gopkg.in/yaml.v2 v2.2.2
 )

go.sum

@@ -16,6 +16,8 @@ github.com/gocolly/colly v1.1.0 h1:B1M8NzjFpuhagut8f2ILUDlWMag+nTx+PWEmPy7RhrE=
 github.com/gocolly/colly v1.1.0/go.mod h1:Hof5T3ZswNVsOHYmba1u03W65HDWgpV5HifSuueE0EA=
 github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/kennygrant/sanitize v1.2.4 h1:gN25/otpP5vAsO2djbMhF/LQX6R7+O1TB4yv8NzpJ3o=
 github.com/kennygrant/sanitize v1.2.4/go.mod h1:LGsjYYtgxbetdg5owWB2mpgUL6e2nfw2eObZ0u0qvak=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
@@ -46,3 +48,6 @@ golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

main.go

@@ -12,7 +12,6 @@ import (
 
 	"github.com/PuerkitoBio/goquery"
 	"github.com/gocolly/colly"
-	"github.com/peterbourgon/ff"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
@@ -139,6 +138,7 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 
 	// OnError callback counts any errors that occur during scraping.
 	c.OnError(func(r *colly.Response, err error) {
+		log.Printf("scrape failed: %d %s", r.StatusCode, http.StatusText(r.StatusCode))
 		e.scrapeErrors.Inc()
 	})
 
@@ -254,45 +254,33 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 
 func main() {
 	var (
-		fs            = flag.NewFlagSet("netgear_cm_exporter", flag.ExitOnError)
-		showVersion   = fs.Bool("version", false, "Print version information.")
-		listenAddress = fs.String("telemetry.addr", "localhost:9527", "Listen address for metrics endpoint.")
-		metricsPath   = fs.String("telemetry.path", "/metrics", "Path to metric exposition endpoint.")
-		modemAddress  = fs.String("modem.address", "192.168.100.1", "Cable modem admin administrative ip address and port.")
-		modemUsername = fs.String("modem.username", "admin", "Modem admin username.")
-		modemPassword = fs.String("modem.password", "", "Modem admin password. (required)")
-		_             = fs.String("config.file", "", "Path to configuration file. (optional)")
-	)
-
-	ff.Parse(fs, os.Args[1:],
-		ff.WithConfigFileFlag("config.file"),
-		ff.WithConfigFileParser(ff.PlainParser),
-		ff.WithEnvVarPrefix("NETGEAR_CM_EXPORTER"),
+		configFile  = flag.String("config.file", "netgear_cm_exporter.yml", "Path to configuration file.")
+		showVersion = flag.Bool("version", false, "Print version information.")
 	)
+	flag.Parse()
 
 	if *showVersion {
 		fmt.Printf("netgear_cm_exporter version=%s revision=%s branch=%s buildUser=%s buildDate=%s\n",
 			version, revision, branch, buildUser, buildDate)
 		os.Exit(0)
 	}
 
-	if *modemPassword == "" {
-		fmt.Println("ERROR: no password provided for modem")
-		fs.PrintDefaults()
-		os.Exit(1)
+	config, err := NewConfigFromFile(*configFile)
+	if err != nil {
+		log.Fatal(err)
 	}
 
-	exporter := NewExporter(*modemAddress, *modemUsername, *modemPassword)
+	exporter := NewExporter(config.Modem.Address, config.Modem.Username, config.Modem.Password)
 
 	prometheus.MustRegister(exporter)
 
-	http.Handle(*metricsPath, promhttp.Handler())
+	http.Handle(config.Telemetry.MetricsPath, promhttp.Handler())
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		http.Redirect(w, r, *metricsPath, http.StatusMovedPermanently)
+		http.Redirect(w, r, config.Telemetry.MetricsPath, http.StatusMovedPermanently)
 	})
 
-	log.Printf("exporter listening on %s", *listenAddress)
-	if err := http.ListenAndServe(*listenAddress, nil); err != nil {
+	log.Printf("exporter listening on %s", config.Telemetry.ListenAddress)
+	if err := http.ListenAndServe(config.Telemetry.ListenAddress, nil); err != nil {
 		log.Fatalf("failed to start netgear exporter: %s", err)
 	}
 }

testdata/minimal.yml

@@ -0,0 +1,2 @@
+modem:
+  password: foobaz