From c5a2e74d5197d3ffdf6c3e6ca134a4be4cac31eb Mon Sep 17 00:00:00 2001
From: Martin Helmich <m.helmich@mittwald.de>
Date: Fri, 15 Jul 2022 13:05:50 +0200
Subject: [PATCH] Correctly process "text/plain" error responses

---
 client_test.go     | 21 +++++++++++++++++++++
 pdnshttp/client.go | 30 +++++++++++++++++++++++-------
 2 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/client_test.go b/client_test.go
index bf1c64a..61ac90c 100644
--- a/client_test.go
+++ b/client_test.go
@@ -144,6 +144,27 @@ func TestCreateZone(t *testing.T) {
 	assert.Equal(t, "example.de.", created.Name)
 }
 
+func TestCreateZoneProducedReadableErrorMessages(t *testing.T) {
+	c := buildClient(t)
+
+	zone := zones.Zone{
+		Name:        "test-error-message.de.",
+		Type:        zones.ZoneTypeZone,
+		Kind:        zones.ZoneKindNative,
+		Nameservers: []string{"ns1.example.com.", "ns2.example.com."},
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	_, err := c.Zones().CreateZone(ctx, "localhost", zone)
+	require.Nil(t, err, "CreateZone returned error")
+
+	_, err2 := c.Zones().CreateZone(ctx, "localhost", zone)
+	require.Error(t, err2, "CreateZone should return error")
+	require.Equal(t, "unexpected status code 409: http://localhost:8081/api/v1/servers/localhost/zones Conflict", err2.Error())
+}
+
 func TestDeleteZone(t *testing.T) {
 	c := buildClient(t)
 
diff --git a/pdnshttp/client.go b/pdnshttp/client.go
index 6ae617e..7c9bd92 100644
--- a/pdnshttp/client.go
+++ b/pdnshttp/client.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"net/http/httputil"
 	"strings"
@@ -88,18 +89,33 @@ func (c *Client) Do(ctx context.Context, req *http.Request, out interface{}) err
 	if res.StatusCode == http.StatusNotFound {
 		return ErrNotFound{URL: req.URL.String()}
 	} else if res.StatusCode >= 400 {
-		// Get a human readable error message
-		// from PowerDNS API response
-		var er ErrResponse
+		if res.Header.Get("Content-Type") == "application/json" {
+			// Get a human readable error message
+			// from PowerDNS API response
+			var er ErrResponse
+
+			if err := json.NewDecoder(res.Body).Decode(&er); err != nil {
+				return err
+			}
+
+			return ErrUnexpectedStatus{
+				URL:         req.URL.String(),
+				StatusCode:  res.StatusCode,
+				ErrResponse: er,
+			}
+		}
 
-		if err := json.NewDecoder(res.Body).Decode(&er); err != nil {
+		body, err := ioutil.ReadAll(res.Body)
+		if err != nil {
 			return err
 		}
 
 		return ErrUnexpectedStatus{
-			URL:         req.URL.String(),
-			StatusCode:  res.StatusCode,
-			ErrResponse: er,
+			URL:        req.URL.String(),
+			StatusCode: res.StatusCode,
+			ErrResponse: ErrResponse{
+				Message: string(body),
+			},
 		}
 	}