Improve error messages derived from the dataplane API.

pkg/haproxy/dataplane.go

@@ -35,6 +35,7 @@ import (
 	"net/http"
 	"net/url"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/go-openapi/strfmt"
@@ -108,7 +109,27 @@ type DataplaneError struct {
 }
 
 func (err *DataplaneError) Error() string {
-	return *err.Err.Message
+	var sb strings.Builder
+	sb.WriteString(http.StatusText(err.Status))
+	sb.WriteString(" (")
+	sb.WriteString(strconv.Itoa(err.Status))
+	sb.WriteString(") version=")
+	sb.WriteString(strconv.Itoa(err.Version))
+	if err.Err.Code != nil {
+		sb.WriteString(" models.Error.Code=")
+		sb.WriteString(strconv.Itoa(int(*err.Err.Code)))
+	}
+	for k, v := range err.Err.Error {
+		sb.WriteRune(' ')
+		sb.WriteString(k)
+		sb.WriteRune('=')
+		sb.WriteString(v)
+	}
+	if err.Err.Message != nil {
+		sb.WriteString(": ")
+		sb.WriteString(*err.Err.Message)
+	}
+	return sb.String()
 }
 
 type DataplaneClient struct {