Automating Email Notifications in Scripts

Table of Contents

Introduction

Email automation in scripts is a crucial component of modern system administration and application monitoring. It enables automatic notification of system events, error alerts, backup completion status, and various other operational updates without manual intervention. This comprehensive guide covers multiple approaches to implementing email notifications across different scripting environments.

Email automation serves several purposes: - System monitoring and alerting - Automated reporting - Error notification and debugging - Backup and maintenance status updates - User notification systems - Integration with CI/CD pipelines

Email Protocols Overview

Understanding email protocols is fundamental to implementing automated email notifications effectively.

SMTP (Simple Mail Transfer Protocol)

SMTP is the standard protocol for sending emails. It operates on specific ports and requires proper authentication.

| Protocol | Port | Security | Description | |----------|------|----------|-------------| | SMTP | 25 | None | Standard unencrypted SMTP | | SMTP | 587 | STARTTLS | Submission port with encryption | | SMTPS | 465 | SSL/TLS | SMTP over SSL | | SMTP | 2587 | STARTTLS | Alternative submission port |

Common Email Providers Configuration

| Provider | SMTP Server | Port | Authentication | |----------|-------------|------|----------------| | Gmail | smtp.gmail.com | 587 | App Password Required | | Outlook | smtp-mail.outlook.com | 587 | OAuth2 or App Password | | Yahoo | smtp.mail.yahoo.com | 587 | App Password Required | | Exchange | mail.company.com | 587 | Domain Authentication |

Setting Up Email Configuration

Gmail Configuration

For Gmail, you need to enable 2-factor authentication and create an app-specific password:

1. Enable 2-Factor Authentication 2. Generate App Password 3. Use app password instead of regular password

Environment Variables Setup

Create a configuration file or use environment variables to store sensitive information:

`bash

Email configuration

Python Implementation

Python provides robust libraries for email automation through the built-in smtplib and email modules.

Basic Email Function

`python import smtplib import ssl from email.mime.text import MIMEText from email.mime.multipart import MIMEMultipart from email.mime.base import MIMEBase from email import encoders import os from datetime import datetime import logging

class EmailNotifier: def __init__(self, smtp_server, smtp_port, username, password): """ Initialize email notifier with SMTP configuration Args: smtp_server (str): SMTP server address smtp_port (int): SMTP server port username (str): Email username password (str): Email password or app password """ self.smtp_server = smtp_server self.smtp_port = smtp_port self.username = username self.password = password self.logger = self._setup_logging() def _setup_logging(self): """Setup logging for email operations""" logging.basicConfig( level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s' ) return logging.getLogger(__name__) def send_email(self, to_email, subject, body, attachments=None, is_html=False): """ Send email with optional attachments Args: to_email (str or list): Recipient email address(es) subject (str): Email subject body (str): Email body content attachments (list): List of file paths to attach is_html (bool): Whether body is HTML formatted Returns: bool: True if email sent successfully, False otherwise """ try: # Create message container msg = MIMEMultipart() msg['From'] = self.username msg['Subject'] = subject # Handle multiple recipients if isinstance(to_email, list): msg['To'] = ', '.join(to_email) recipients = to_email else: msg['To'] = to_email recipients = [to_email] # Add timestamp to body timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S") body_with_timestamp = f"{body}\n\nSent at: {timestamp}" # Attach body if is_html: msg.attach(MIMEText(body_with_timestamp, 'html')) else: msg.attach(MIMEText(body_with_timestamp, 'plain')) # Add attachments if provided if attachments: for file_path in attachments: if os.path.isfile(file_path): self._attach_file(msg, file_path) else: self.logger.warning(f"Attachment not found: {file_path}") # Create secure connection and send email context = ssl.create_default_context() with smtplib.SMTP(self.smtp_server, self.smtp_port) as server: server.starttls(context=context) server.login(self.username, self.password) server.sendmail(self.username, recipients, msg.as_string()) self.logger.info(f"Email sent successfully to {recipients}") return True except Exception as e: self.logger.error(f"Failed to send email: {str(e)}") return False def _attach_file(self, msg, file_path): """ Attach file to email message Args: msg: Email message object file_path (str): Path to file to attach """ with open(file_path, "rb") as attachment: part = MIMEBase('application', 'octet-stream') part.set_payload(attachment.read()) encoders.encode_base64(part) part.add_header( 'Content-Disposition', f'attachment; filename= {os.path.basename(file_path)}' ) msg.attach(part) def send_system_alert(self, alert_type, message, severity="INFO"): """ Send system alert with predefined formatting Args: alert_type (str): Type of alert (ERROR, WARNING, INFO) message (str): Alert message severity (str): Severity level """ subject = f"[{severity}] System Alert: {alert_type}" body = f""" System Alert Notification

Alert Type: {alert_type} Severity: {severity} Message: {message} Hostname: {os.uname().nodename if hasattr(os, 'uname') else 'Unknown'} Timestamp: {datetime.now().isoformat()}

This is an automated message from your monitoring system. """ # Determine recipients based on severity recipients = self._get_recipients_by_severity(severity) return self.send_email(recipients, subject, body.strip()) def _get_recipients_by_severity(self, severity): """Get email recipients based on alert severity""" recipients = { "CRITICAL": ["admin@company.com", "oncall@company.com"], "ERROR": ["admin@company.com"], "WARNING": ["admin@company.com"], "INFO": ["notifications@company.com"] } return recipients.get(severity, ["admin@company.com"])

Configuration and usage example

if __name__ == "__main__": main() `

Advanced Python Email Templates

`python class EmailTemplates: """Predefined email templates for common notifications""" @staticmethod def backup_completion_template(backup_name, status, size, duration): """Template for backup completion notifications""" if status.lower() == 'success': subject = f"Backup Completed Successfully: {backup_name}" body = f""" Backup Operation Completed

Backup Name: {backup_name} Status: SUCCESS Size: {size} Duration: {duration} Completion Time: {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}

All files have been successfully backed up. """ else: subject = f"Backup Failed: {backup_name}" body = f""" Backup Operation Failed

Backup Name: {backup_name} Status: FAILED Error Details: {size} # Reusing parameter for error message Duration: {duration} Failure Time: {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}

Please check the backup system immediately. """ return subject, body.strip() @staticmethod def disk_space_alert_template(filesystem, usage_percent, available_space): """Template for disk space alerts""" subject = f"Disk Space Alert: {filesystem} at {usage_percent}%" if usage_percent >= 95: severity = "CRITICAL" elif usage_percent >= 85: severity = "WARNING" else: severity = "INFO" body = f""" Disk Space Alert

Filesystem: {filesystem} Usage: {usage_percent}% Available Space: {available_space} Severity: {severity} Check Time: {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}

{'IMMEDIATE ACTION REQUIRED!' if usage_percent >= 95 else 'Please monitor closely.'} """ return subject, body.strip() `

Bash Shell Implementation

Bash scripts can send emails using various methods including mail, sendmail, and curl.

Using mail command

`bash #!/bin/bash

Email configuration

Function to send simple email using mail command

Function to send email using curl (more reliable for external SMTP)

--$boundary Content-Type: text/plain; charset=UTF-8

$body

Sent at: $(date '+%Y-%m-%d %H:%M:%S') EOF

# Add attachment if provided if [ -n "$attachment" ] && [ -f "$attachment" ]; then cat >> "$email_file" << EOF

--$boundary Content-Type: application/octet-stream Content-Disposition: attachment; filename="$(basename "$attachment")" Content-Transfer-Encoding: base64

$(base64 "$attachment") EOF fi echo "--$boundary--" >> "$email_file" # Send email using curl curl --url "smtp://$SMTP_SERVER:$SMTP_PORT" \ --ssl-reqd \ --mail-from "$FROM_EMAIL" \ --mail-rcpt "$to_email" \ --upload-file "$email_file" \ --user "$EMAIL_USER:$EMAIL_PASS" \ --silent local exit_code=$? # Clean up temporary file rm -f "$email_file" if [ $exit_code -eq 0 ]; then echo "Email sent successfully to $to_email using curl" log_email_event "SUCCESS" "$to_email" "$subject" else echo "Failed to send email to $to_email using curl" log_email_event "FAILED" "$to_email" "$subject" fi return $exit_code }

Function to log email events

Function to send system alert

Alert Type: $alert_type Severity: $severity Message: $message Hostname: $(hostname) Timestamp: $(date '+%Y-%m-%d %H:%M:%S')

This is an automated message from your monitoring system." # Determine recipients based on severity local recipients case "$severity" in "CRITICAL") recipients="admin@company.com,oncall@company.com" ;; "ERROR"|"WARNING") recipients="admin@company.com" ;; *) recipients="notifications@company.com" ;; esac # Send to multiple recipients IFS=',' read -ra ADDR <<< "$recipients" for recipient in "${ADDR[@]}"; do send_email_curl "$recipient" "$subject" "$body" done }

Function to monitor disk space and send alerts

Function to check service status and send alerts

Main execution example