Truncate error messages in CA config map to 500 characters per node g…

…roup.

Max size of configmap is 1MB.

Change-Id: I615d25781e4f8dafb6a08f752c085544bcd49e5a

cluster-autoscaler/clusterstate/clusterstate.go

@@ -45,6 +45,10 @@ import (
 const (
 	// MaxNodeStartupTime is the maximum time from the moment the node is registered to the time the node is ready.
 	MaxNodeStartupTime = 15 * time.Minute
+	// maxErrorMessageSize is the maximum size of error messages displayed in config map as the max size of configmap is 1MB.
+	maxErrorMessageSize = 500
+	// messageTrancated is displayed at the end of a trancated message.
+	messageTrancated = "<truncated>"
 )
 
 var (
@@ -852,7 +856,7 @@ func (csr *ClusterStateRegistry) buildScaleUpStatusNodeGroup(nodeGroup cloudprov
 		condition.Status = api.ClusterAutoscalerBackoff
 		condition.BackoffInfo = api.BackoffInfo{
 			ErrorCode:    scaleUpSafety.BackoffStatus.ErrorInfo.ErrorCode,
-			ErrorMessage: scaleUpSafety.BackoffStatus.ErrorInfo.ErrorMessage,
+			ErrorMessage: truncateIfExceedMaxLength(scaleUpSafety.BackoffStatus.ErrorInfo.ErrorMessage, maxErrorMessageSize),
 		}
 	} else {
 		condition.Status = api.ClusterAutoscalerNoActivity
@@ -1251,3 +1255,14 @@ func (csr *ClusterStateRegistry) GetScaleUpFailures() map[string][]ScaleUpFailur
 	}
 	return result
 }
+
+func truncateIfExceedMaxLength(s string, maxLength int) string {
+	if len(s) <= maxLength {
+		return s
+	}
+	untrancatedLen := maxLength - len(messageTrancated)
+	if untrancatedLen < 0 {
+		return s[:maxLength]
+	}
+	return s[:untrancatedLen] + messageTrancated
+}

cluster-autoscaler/clusterstate/clusterstate_test.go

@@ -1325,3 +1325,44 @@ func TestUpdateIncorrectNodeGroupSizes(t *testing.T) {
 		})
 	}
 }
+
+func TestTruncateIfExceedMaxSize(t *testing.T) {
+	testCases := []struct {
+		name        string
+		message     string
+		maxSize     int
+		wantMessage string
+	}{
+		{
+			name:        "Message doesn't exceed maxSize",
+			message:     "Some message",
+			maxSize:     len("Some message"),
+			wantMessage: "Some message",
+		},
+		{
+			name:        "Message exceeds maxSize",
+			message:     "Some long message",
+			maxSize:     len("Some long message") - 1,
+			wantMessage: "Some <truncated>",
+		},
+		{
+			name:        "Message doesn't exceed maxSize and maxSize is smaller than truncatedMessageSuffix length",
+			message:     "msg",
+			maxSize:     len("msg"),
+			wantMessage: "msg",
+		},
+		{
+			name:        "Message exceeds maxSize and maxSize is smaller than truncatedMessageSuffix length",
+			message:     "msg",
+			maxSize:     2,
+			wantMessage: "ms",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := truncateIfExceedMaxLength(tc.message, tc.maxSize)
+			assert.Equal(t, tc.wantMessage, got)
+		})
+	}
+}