python script to add a label match to grafana dashboard json files

grafana-dash-add-label-2-expressions.py

import json
import re
import glob
import os

def add_environment_label(dashboard_file, new_label: str):
    # Read the dashboard JSON
    with open(dashboard_file, 'r', encoding='utf-8') as f:
        dashboard = json.load(f)
    
    # Regular expression to find metric expressions and add environment label
    metric_pattern = re.compile(r'([a-zA-Z_][a-zA-Z0-9_]*)\{([^}]*)\}')
    
    modified = False
    
    # Recursively search for targets in panels
    def process_targets(data, new_label: str):
        nonlocal modified
        if isinstance(data, dict):
            if 'targets' in data:
                for target in data['targets']:
                    if 'expr' in target:
                        # Process the expression
                        def replacer(m):
                            base = m.group(1)
                            labels = m.group(2)
                            new_labels = f'{labels}, ' if labels else ''
                            new_labels += new_label
                            return f'{base}{{{new_labels}}}'
                        
                        new_expr = metric_pattern.sub(replacer, target['expr'])
                        if new_expr != target['expr']:
                            target['expr'] = new_expr
                            modified = True
            for key, value in data.items():
                process_targets(value, new_label)
        elif isinstance(data, list):
            for item in data:
                process_targets(item, new_label)
    
    process_targets(dashboard, new_label)
    
    if modified:
        # Backup original file
        backup_file = dashboard_file + '.bak'
        if not os.path.exists(backup_file):
            os.rename(dashboard_file, backup_file)
        
        # Write modified dashboard
        with open(dashboard_file, 'w', encoding='utf-8') as f:
            json.dump(dashboard, f, indent=2, ensure_ascii=False)
        print(f"Modified {dashboard_file}")
    else:
        print(f"No changes needed for {dashboard_file}")

# Process all JSON files in the current directory

# define your label as below:
new_label = 'environment="$environment"'
for dashboard_file in glob.glob('*.json'):
    add_environment_label(dashboard_file, new_label)