Improve logging, show usage if flag is missing

This commit is contained in:
Mathias Petermann 2021-11-12 14:23:12 +01:00
parent 34d415c13f
commit b1b0584f9d

93
main.go
View file

@ -7,6 +7,7 @@ import (
"io/ioutil"
"log"
"net/http"
"os"
"time"
"github.com/prometheus/client_golang/prometheus"
@ -88,47 +89,10 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
func (e *Exporter) FetchSwitchMetrics(switchIP string, ch chan<- prometheus.Metric) {
log.Printf("Trying to connect to switch at: %s\n", switchIP)
report, err := FetchReport(switchIP)
url := "http://" + switchIP + "/report"
switchClient := http.Client{
Timeout: time.Second * 5, // 3 second timeout, might need to be increased
}
req, err := http.NewRequest(http.MethodGet, url, nil)
if err != nil {
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
}
req.Header.Set("User-Agent", "myStrom-exporter")
res, getErr := switchClient.Do(req)
if getErr != nil {
fmt.Printf("Error while trying to connect to switch: %v\n", getErr)
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
}
if res.Body != nil {
defer res.Body.Close()
}
body, readErr := ioutil.ReadAll(res.Body)
if readErr != nil {
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
}
report := switchReport{}
err = json.Unmarshal(body, &report)
if err != nil {
fmt.Println(err)
log.Printf("Error occured, while fetching metrics: %s", err)
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
@ -159,12 +123,56 @@ func (e *Exporter) FetchSwitchMetrics(switchIP string, ch chan<- prometheus.Metr
}
func FetchReport(switchIP string) (*switchReport, error) {
log.Printf("Trying to connect to switch at: %s\n", switchIP)
url := "http://" + switchIP + "/report"
switchClient := http.Client{
Timeout: time.Second * 5, // 3 second timeout, might need to be increased
}
req, err := http.NewRequest(http.MethodGet, url, nil)
if err != nil {
return nil, err
}
req.Header.Set("User-Agent", "myStrom-exporter")
res, getErr := switchClient.Do(req)
if getErr != nil {
log.Printf("Error while trying to connect to switch: %s\n", getErr)
return nil, getErr
}
if res.Body != nil {
defer res.Body.Close()
}
body, readErr := ioutil.ReadAll(res.Body)
if readErr != nil {
log.Printf("Error while reading body: %s\n", readErr)
return nil, readErr
}
report := switchReport{}
err = json.Unmarshal(body, &report)
if err != nil {
log.Printf("Error while unmarshaling report: %s\n", err)
return nil, err
}
return &report, nil
}
func main() {
flag.Parse()
if *switchIP == "" {
log.Fatal("No switch.ip-address provided")
flag.Usage()
fmt.Println("\nNo switch.ip-address provided")
os.Exit(1)
}
exporter := NewExporter(*switchIP)
@ -181,6 +189,11 @@ func main() {
</html>`))
})
_, err := FetchReport(*switchIP)
if err != nil {
log.Fatalf("Switch at address %s couldn't be reached. Ensure it is reachable before starting the exporter", *switchIP)
}
log.Printf("Starting listener on %s\n", *listenAddress)
log.Fatal(http.ListenAndServe(*listenAddress, nil))
}