cloud-gov-instructions: Instructions file for GitHub Copilot

Cloud.gov Logging Instructions

This document provides guidance for implementing logging and monitoring in cloud.gov applications.

Overview

Cloud.gov automatically captures logs written to stdout and stderr. Applications should:

• Write all logs to stdout/stderr (not files)
• Use structured logging (JSON format recommended)
• Include contextual information for debugging
• Never log sensitive data (PII, credentials, tokens)

Viewing Logs

Recent Logs

# View recent logs (last ~100 lines)
cf logs my-app --recent

Stream Live Logs

# Stream logs in real-time
cf logs my-app

# Press Ctrl+C to stop streaming

Log Types

Cloud.gov provides several log types:

Type	Source	Description
APP	Application	Your application's stdout/stderr
RTR	Router	HTTP request logs
STG	Staging	Build/staging process logs
CELL	Cell	Container lifecycle events
API	Cloud Controller	CF CLI operations

Filter Logs

# View only application logs (grep for APP)
cf logs my-app --recent | grep "\[APP"

# View only router logs
cf logs my-app --recent | grep "\[RTR"

Application Logging

Basic Logging Configuration

Python

import logging
import sys

# Configure logging to stdout
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
    handlers=[logging.StreamHandler(sys.stdout)]
)

logger = logging.getLogger(__name__)

# Log messages
logger.info("Application started")
logger.warning("Something might be wrong")
logger.error("An error occurred")

Node.js

const winston = require('winston');

const logger = winston.createLogger({
  level: 'info',
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.json()
  ),
  transports: [
    new winston.transports.Console()
  ]
});

// Log messages
logger.info('Application started');
logger.warn('Something might be wrong');
logger.error('An error occurred');