Introduce new preview auto-scaling mode for ARC. (#2153)

Co-authored-by: Cory Miller <cory-miller@github.com>
Co-authored-by: Nikola Jokic <nikola-jokic@github.com>
Co-authored-by: Ava Stancu <AvaStancu@github.com>
Co-authored-by: Ferenc Hammerl <fhammerl@github.com>
Co-authored-by: Francesco Renzi <rentziass@github.com>
Co-authored-by: Bassem Dghaidi <Link-@github.com>

github/actions/errors.go

@@ -0,0 +1,71 @@
+package actions
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+)
+
+type ActionsError struct {
+	ExceptionName string `json:"typeName,omitempty"`
+	Message       string `json:"message,omitempty"`
+	StatusCode    int
+}
+
+func (e *ActionsError) Error() string {
+	return fmt.Sprintf("%v - had issue communicating with Actions backend: %v", e.StatusCode, e.Message)
+}
+
+func ParseActionsErrorFromResponse(response *http.Response) error {
+	if response.ContentLength == 0 {
+		message := "Request returned status: " + response.Status
+		return &ActionsError{
+			ExceptionName: "unknown",
+			Message:       message,
+			StatusCode:    response.StatusCode,
+		}
+	}
+
+	defer response.Body.Close()
+	body, err := io.ReadAll(response.Body)
+	if err != nil {
+		return err
+	}
+
+	body = trimByteOrderMark(body)
+	contentType, ok := response.Header["Content-Type"]
+	if ok && len(contentType) > 0 && strings.Contains(contentType[0], "text/plain") {
+		message := string(body)
+		statusCode := response.StatusCode
+		return &ActionsError{
+			Message:    message,
+			StatusCode: statusCode,
+		}
+	}
+
+	actionsError := &ActionsError{StatusCode: response.StatusCode}
+	if err := json.Unmarshal(body, &actionsError); err != nil {
+		return err
+	}
+
+	return actionsError
+}
+
+type MessageQueueTokenExpiredError struct {
+	msg string
+}
+
+func (e *MessageQueueTokenExpiredError) Error() string {
+	return e.msg
+}
+
+type HttpClientSideError struct {
+	msg  string
+	Code int
+}
+
+func (e *HttpClientSideError) Error() string {
+	return e.msg
+}