initial release

internal/httputil/client.go

@@ -0,0 +1,87 @@
+package httputil // import "github.com/pomerium/pomerium/internal/httputil"
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+// ErrTokenRevoked signifies a token revokation or expiration error
+var ErrTokenRevoked = errors.New("Token expired or revoked")
+
+var httpClient = &http.Client{
+	Timeout: time.Second * 5,
+	Transport: &http.Transport{
+		Dial: (&net.Dialer{
+			Timeout: 2 * time.Second,
+		}).Dial,
+		TLSHandshakeTimeout: 2 * time.Second,
+	},
+}
+
+// Client provides a simple helper interface to make HTTP requests
+func Client(method, endpoint, userAgent string, params url.Values, response interface{}) error {
+	var body io.Reader
+	switch method {
+	case "POST":
+		body = bytes.NewBufferString(params.Encode())
+	case "GET":
+		// error checking skipped because we are just parsing in
+		// order to make a copy of an existing URL
+		u, _ := url.Parse(endpoint)
+		u.RawQuery = params.Encode()
+		endpoint = u.String()
+	default:
+		return fmt.Errorf(http.StatusText(http.StatusBadRequest))
+	}
+	req, err := http.NewRequest(method, endpoint, body)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("User-Agent", userAgent)
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return err
+	}
+
+	var respBody []byte
+	respBody, err = ioutil.ReadAll(resp.Body)
+	resp.Body.Close()
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		switch resp.StatusCode {
+		case http.StatusBadRequest:
+			var response struct {
+				Error            string `json:"error"`
+				ErrorDescription string `json:"error_description"`
+			}
+			e := json.Unmarshal(respBody, &response)
+			if e == nil && response.ErrorDescription == "Token expired or revoked" {
+				return ErrTokenRevoked
+			}
+			return fmt.Errorf(http.StatusText(http.StatusBadRequest))
+		default:
+			return fmt.Errorf(http.StatusText(resp.StatusCode))
+		}
+	}
+
+	if response != nil {
+		err := json.Unmarshal(respBody, &response)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}