expvarmon/expvars.go

62 lines
1.3 KiB
Go

package main
import (
"errors"
"io"
"net/http"
"net/url"
"os"
"time"
"github.com/antonholmquist/jason"
)
// DefaultEndpoint is the default url for fetching expvar info.
var DefaultEndpoint = "/debug/vars"
// Expvar represents fetched expvar variable.
type Expvar struct {
*jason.Object
}
func getBasicAuthEnv() (user, password string) {
return os.Getenv("HTTP_USER"), os.Getenv("HTTP_PASSWORD")
}
// FetchExpvar fetches expvar by http for the given addr (host:port)
func FetchExpvar(u url.URL) (*Expvar, error) {
e := &Expvar{&jason.Object{}}
client := &http.Client{
Timeout: 1 * time.Second, // TODO: make it configurable or left default?
}
req, _ := http.NewRequest("GET", "localhost", nil)
req.URL = &u
req.Host = u.Host
if user, pass := getBasicAuthEnv(); user != "" && pass != "" {
req.SetBasicAuth(user, pass)
}
resp, err := client.Do(req)
if err != nil {
return e, err
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusNotFound {
return e, errors.New("Vars not found. Did you import expvars?")
}
expvar, err := ParseExpvar(resp.Body)
if err != nil {
return e, err
}
e = expvar
return e, nil
}
// ParseExpvar parses expvar data from reader.
func ParseExpvar(r io.Reader) (*Expvar, error) {
object, err := jason.NewObjectFromReader(r)
return &Expvar{object}, err
}