Replace kingpin with stdlib flags

hagaibarel · hagaibarel · commit ee964bd35b02 · 2020-04-27T18:14:48.000+03:00
diff --git a/Makefile b/Makefile
@@ -41,7 +41,7 @@ local: ## Start a local emq container for development
 	@docker run --rm -d --name emqx -h emqx -p 18083:18083 -p 8080:8080 emqx/emqx:latest
 
 run: build local ## Run the exporter locally using a local container
-	./bin/emq_exporter -n emqx@$(IP) -f testdata/authfull.json --emq.api-version v4 --log.level debug
+	./bin/emq_exporter --emq.node emqx@$(IP) --emq.creds-file testdata/authfull.json --emq.api-version v4 --log.level debug
 
 help: ## Print this message and exit
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "%-20s %s\n", $$1, $$2}'
diff --git a/README.md b/README.md
@@ -27,7 +27,7 @@ Help on flags:
 
 ### EMQ URI
 
-Specify EMQ's node uri and api port using the `--emq.uri` flag (short `-u`). For example,
+Specify EMQ's node uri and api port using the `--emq.uri` flag. For example,
 
 ```bash
 ./emq_exporter --emq.uri "http://localhost:8080"
@@ -36,7 +36,7 @@ Specify EMQ's node uri and api port using the `--emq.uri` flag (short `-u`). For
 Or to scrape a remote host:
 
 ```bash
-./emq_exporter -u "https://emq.example.com:8080"
+./emq_exporter -emq.uri "https://emq.example.com:8080"
 ```
 
 ### Passing Credentials
@@ -60,10 +60,10 @@ The file should be json formatted and contain the following fields:
 }
 ```
 
-When staring `emq_exporter`, point it to the credentials file using `--emq.creds-file` flag (short `-f`):
+When staring `emq_exporter`, point it to the credentials file using `--emq.creds-file` flag:
 
 ```bash
-./emq_exporter -u http://localhost:8080 -f /etc/emq_exporter/auth.json
+./emq_exporter --emq.uri http://localhost:8080 --emq.creds-file /etc/emq_exporter/auth.json
 ```
 
 The default path for credentials file is `$(CWD)/auth.json`. Note that `env vars` take precedence over using a file.
@@ -73,16 +73,16 @@ The default path for credentials file is `$(CWD)/auth.json`. Note that `env vars
 EMQ add a `v3` api version in `EMQX`. To specify the api version, use the `emq.api-version` flag:
 
 ```bash
-./emq_exporter -u http://localhost:8080 --emq.api-version v3
+./emq_exporter --emq.uri http://localhost:8080 --emq.api-version v3
 ```
 
-The `emq_exporter` supports both `v2` and `v3` API versions seamlessly (mutually exclusive, pick either on start up), default is `v2`.
+The `emq_exporter` supports `v2`, `v3` and `v4` API versions seamlessly (mutually exclusive, pick either on start up), default is `v3`.
 
 ### Authentication
 
-The authentication method changed a bit in version `v3` of `emqx`. If you're pulling the metrics through the dashboard port (default `18083`), you can use regular username and password. However, if you're using the API port (default `8080`), you'll need to set up application credentials: 
+The authentication method changed a bit in version `v3` of `emqx`. If you're pulling the metrics through the dashboard port (default `18083`), you can use regular username and password. However, if you're using the API port (default `8080`), you'll need to set up application credentials:
 1. From the emq dashboard side bar -> applications
-2. Select `New App` from the top 
+2. Select `New App` from the top
 3. Fill in the popup window with the relevant details and confirm
 4. View the app details and use `AppID` as `username` and `AppSecret` as `password` (as `creds-file` entries or `env vars`, see above)
 
@@ -115,7 +115,7 @@ Alternatively, One can also supply the credentials using `env vars`, replace the
 
 ### Kubernetes
 
-EMQ exporter was designed to run as a sidecar in the same pod as EMQ itself. 
+EMQ exporter was designed to run as a sidecar in the same pod as EMQ itself.
 See the examples folder for a `kubernetes` manifest that can serve as reference for implementation.
 
 ## Contributing
diff --git a/emq_exporter.go b/emq_exporter.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"net/http"
 	"strings"
@@ -10,7 +11,6 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/log"
-	kingpin "gopkg.in/alecthomas/kingpin.v2"
 )
 
 const (
@@ -163,22 +163,19 @@ func (e *Exporter) add(fqName, help string, value float64) {
 }
 
 func main() {
-	var (
-		listenAddress = kingpin.Flag("web.listen-address", "Address to listen on for web interface and telemetry.").Default(":9540").String()
-		metricsPath   = kingpin.Flag("web.telemetry-path", "Path under which to expose metrics.").Default("/metrics").String()
-		emqURI        = kingpin.Flag("emq.uri", "HTTP API address of the EMQ node.").Default("http://127.0.0.1:18083").Short('u').String()
-		emqCreds      = kingpin.Flag("emq.creds-file", "Path to json file containing emq credentials").Default("./auth.json").Short('f').String()
-		emqNodeName   = kingpin.Flag("emq.node", "Node name of the emq node to scrape.").Default("emq@127.0.0.1").Short('n').String()
-		emqAPIVersion = kingpin.Flag("emq.api-version", "The API version used by EMQ. Valid values: [v2, v3, v4]").Default("v3").Enum("v2", "v3", "v4")
-	)
 
-	log.AddFlags(kingpin.CommandLine)
-	kingpin.Version(fmt.Sprintf("Version %s (git-%s)", GitTag, GitCommit))
-	kingpin.CommandLine.HelpFlag.Short('h')
+	emqAPIVersion := flag.String("emq.api-version", "v3", "The API version used by EMQ. Valid values: [v2, v3, v4]")
+	emqCreds := flag.String("emq.creds-file", "./auth.json", "Path to json file containing emq credentials")
+	emqNodeName := flag.String("emq.node", "emq@127.0.0.1", "Node name of the emq node to scrape")
+	emqURI := flag.String("emq.uri", "http://127.0.0.1:18083", "HTTP API address of the EMQ node")
+	logLevel := flag.String("log.level", "info", "log level")
+	webListenAddress := flag.String("web.listen-address", ":9540", "Address to listen on for web interface and telemetry")
+	webMetricsPath := flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics")
 
-	kingpin.Parse()
+	flag.Parse()
 
 	log.Infoln("Loading authentication credentials")
+	log.Debugf("log level: %s", *logLevel)
 
 	username, password, err := findCreds(*emqCreds)
 	if err != nil {
@@ -188,8 +185,12 @@ func main() {
 	log.Infoln("Starting emq_exporter")
 	log.Infof("Version %s (git-%s)", GitTag, GitCommit)
 
-	if *emqAPIVersion == "v2" {
+	switch *emqAPIVersion {
+	case "v2":
 		log.Warnln("v2 api version is deprecated and will be removed in future versions")
+	case "v3", "v4":
+	default:
+		log.Fatalf("unsupported api version: %s", *emqAPIVersion)
 	}
 
 	c := client.NewClient(*emqURI, *emqNodeName, *emqAPIVersion, username, password)
@@ -198,17 +199,18 @@ func main() {
 
 	prometheus.MustRegister(exporter)
 
-	log.Infoln("Listening on", *listenAddress)
-	http.Handle(*metricsPath, promhttp.Handler())
+	log.Infoln("Listening on", *webListenAddress)
+
+	http.Handle(*webMetricsPath, promhttp.Handler())
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte(`<html>
              <head><title>EMQ Exporter</title></head>
              <body>
              <h1>EMQ Exporter</h1>
-             <p><a href='` + *metricsPath + `'>Metrics</a></p>
+             <p><a href='` + *webMetricsPath + `'>Metrics</a></p>
              </body>
              </html>`))
 	})
 
-	log.Fatal(http.ListenAndServe(*listenAddress, nil))
+	log.Fatal(http.ListenAndServe(*webListenAddress, nil))
 }
diff --git a/examples/manifests/deployment.yaml b/examples/manifests/deployment.yaml
@@ -28,7 +28,7 @@ spec:
       serviceAccountName: emqx
       containers:
       - name: exporter
-        image: "nuvo/emq_exporter:v0.3.1"
+        image: "nuvo/emq_exporter:v0.5.0"
         env:
         - name: EMQ_USERNAME
           value: "admin"
diff --git a/go.mod b/go.mod
@@ -14,7 +14,6 @@ require (
 	golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0 // indirect
 	golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f // indirect
 	golang.org/x/text v0.3.2 // indirect
-	gopkg.in/alecthomas/kingpin.v2 v2.2.6
 	gopkg.in/yaml.v2 v2.2.8 // indirect
 )
 

Original file line number	Diff line number	Diff line change
`@@ -14,7 +14,6 @@ require (`
`14`	`14`	`golang.org/x/net v0.0.0-20200425230154-ff2c4b7c35a0 // indirect`
`15`	`15`	`golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f // indirect`
`16`	`16`	`golang.org/x/text v0.3.2 // indirect`
`17`		`- gopkg.in/alecthomas/kingpin.v2 v2.2.6`
`18`	`17`	`gopkg.in/yaml.v2 v2.2.8 // indirect`
`19`	`18`	`)`
`20`	`19`