PM2 Checker (PM2 Status Monitor and SMS Notification Updater)

This Node.js script provides automated monitoring of applications managed by PM2, a production process manager for Node.js. It checks the status of each application, identifies those that are in a 'stopped' or 'nonExistent' state, and records these events in a log file (checking.log).

The script is designed to facilitate SMS notifications when applications encounter issues. It updates the checking.log file, adding a flag to indicate that an SMS notification should be sent. A key feature is the ability to control SMS notifications based on the time of day, allowing you to suppress notifications during off-hours (e.g., at night) if desired. This is managed through a configurable isNightModeActive setting.

The script is designed to run periodically (e.g., using cron or a similar task scheduler) to provide continuous monitoring and timely alerts.

🌟 Features

PM2 Process Monitoring: Retrieves the status of all applications managed by PM2.

Status Filtering: Identifies applications that are in a 'stopped' or 'nonExistent' state, indicating potential issues.

Log File Recording: Records the status of problematic applications in a checking.log file.

Unique Log Entry Generation: Creates a unique ID for each log entry.

Duplicate Entry Prevention: Prevents duplicate log entries for the same application status.

SMS Notification Trigger: Updates the checking.log file to indicate when an SMS notification should be sent for a specific application issue.

Time-Based SMS Control: Allows configuration to suppress SMS notifications during specified hours (e.g., for "night mode").

Configurable Night Mode: isNightModeActive variable allows to enable or disable night mode.

Modular Design: The code is structured into functions (getPM2ProcessOutput, updateCheckingFile, notifyWithFunction) for readability and maintainability.

Error Handling: Includes basic error handling for file system operations and command execution.

Extensible Notification System: The notifyWithFunction is designed to be easily extended to integrate with your preferred SMS or notification service.

💡 Guide on How to Use This Script

Node.js Packages Used

child_process: Included with Node.js, so no installation is necessary. Used for executing shell commands (e.g., pm2 ls).

moment: For date and time formatting.

fs: Included with Node.js, so no installation is necessary. Used for file system operations (reading and writing to the log file).

path: Included with Node.js, so no installation is necessary. Used for constructing file paths.

How to Install Packages

1. Install Node.js and npm: Make sure you have Node.js and npm (Node Package Manager) installed on your system. You can download them from the official Node.js website (https://nodejs.org/).

2. Navigate to the Script Directory: Open a terminal or command prompt and navigate to the directory where you have saved the script.

3. Install the Required Package: Run the following command to install the moment package:

npm install fs path moment

How to Run the Script Every Minute via Crontab

1. Open Crontab: Open the crontab editor by running the following command in your terminal:

crontab -e
This will open the crontab file in a text editor. If this is the first time you're using crontab, it might ask you to choose an editor.

2. Add a Cron Entry: Add the following line to the crontab file to run the script every minute:

* * * * * /usr/bin/node /path/to/your/script.js >> /path/to/your/script.log 2>&1

Replace /usr/bin/node with the actual path to your Node.js executable. You can find this by running which node in your terminal.

Replace /path/to/your/script.js with the full path to your script file.

Replace /path/to/your/script.log with the desired path to a log file. This will capture the output of the script. The 2>&1 redirects standard error to the same log file.

3. Save and Close: Save the crontab file and close the editor. The cron daemon will automatically pick up the changes.

▚ A Node.js script that monitors the status of PM2-managed applications, logs stopped or non-existent processes, and updates a log file to trigger SMS notifications based on configurable time-of-day rules.

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Thank you for choosing the PM2 Checker! I hope it meets your needs effectively.
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