- Show in the line tooltip the number of the query which generates the given line.
This simplifies comparison of lines generated by multiple queries.
- Show metric name as __name__ label in the line tooltip in the same way as other labels are shown there.
This makes the label information in the tooltip more consistent.
- Properly quote label values with JSON.stringify(). This prevents from improper formatting
when label values contain doublequote chars.
- Remove double curly braces artifact at graph legend for lines without names and labels.
- Properly use modifier for regular expressions across the code.
