Uptime Robot + WordPress

Why use Uptime Robot for monitoring websites in WordPress?

Monitoring our website’s uptime is essential to ensure its reliability, especially for critical systems. In this post, we’ll see how I use the Uptime Robot API—a popular and robust third-party tool—to automate uptime tracking directly in WordPress.

Why Uptime Robot?

We chose Uptime Robot because:

1. Popular and robust: Uptime Robot has a proven track record of reliability. It’s trusted by thousands of users worldwide and simply works.
2. Third-party reliability: Using a third-party tool ensures that even if our systems are down, we can still monitor and access the status page.
3. Why not self-host? While tools like Uptime Kuma are great alternatives, self-hosted solutions could fail alongside our systems, leaving us unable to track status when we need it most.
4. Notifications: We can trigger instant notifications like an email when our site is down!
5. Free Tier and API: Uptime Robot’s free tier offers generous features, including an API that we leverage here. The API is read-only, so there are no security concerns about unwanted modifications.

Data retention

By default, Uptime Robot’s free tier retains uptime history for 90 days. However, by using this WordPress solution:

• We will use posts as data storage: Each day’s uptime data is saved as a new WordPress post, allowing unlimited retention (or as much as our hosting storage permits).
• We control our data, and it’s always available for reference.

Using WordPress posts instead of a custom post type

Why store uptime data in standard posts?

• This solution is designed for a dedicated status site (e.g., status.oursite.com) that has no other content.
• Posts provide a simple and effective structure to display uptime information dynamically without the overhead of custom post types.

How it works

1. Fetches site status and 24-hour uptime percentage every 5 minutes using WP-Cron.
2. Each day, a new post is created with:
   • Title: Current date in dd-mm-yyyy format.
   • Tags: Status values like success, outage, or unknown.
   • Custom Field: Uptime percentage for the last “day”.
3. Uptime Robot status returned value –> stored status
   • 2 = success
   • 8 and 9 = outage
   • 0 and 1 = unknown
4. Unlimited Data Retention:
   • Posts ensure our uptime data remains stored indefinitely without expiration

TLDR – the code

Below is an extract of the custom plugin I created:

// Schedule the cron job when the plugin is activated
register_activation_hook(__FILE__, function() {
    // Schedule the 'check_uptime_status' event to run every 5 minutes if not already scheduled
    if (!wp_next_scheduled('check_uptime_status')) {
        wp_schedule_event(time(), 'five_minutes', 'check_uptime_status');
    }
});

// Clear the cron job when the plugin is deactivated
register_deactivation_hook(__FILE__, function() {
    // Remove the scheduled 'check_uptime_status' event
    wp_clear_scheduled_hook('check_uptime_status');
});

// Add a custom cron interval for 5 minutes
add_filter('cron_schedules', function($schedules) {
    // Define a new schedule 'five_minutes' with an interval of 300 seconds (5 minutes)
    $schedules['five_minutes'] = [
        'interval' => 300, // 5 minutes
        'display'  => __('Every 5 Minutes', 'uptime-robot-connector')
    ];
    return $schedules;
});

// Main function to check the uptime status and update WordPress posts
add_action('check_uptime_status', function() {
    $api_key = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'; // Uptime Robot API key
    $uptime_url = "https://api.uptimerobot.com/v2/getMonitors"; // Uptime Robot API endpoint

    // Make an API request to UptimeRobot to fetch monitor data with a 30-second timeout
    $response = wp_remote_post($uptime_url, [
        'timeout' => 30, // API request timeout
        'body' => [
            'api_key' => $api_key,
            'format'  => 'json',
            'custom_uptime_ratios' => '1' // Request uptime percentage for the last day
        ]
    ]);

    // Check for API errors or invalid responses
    if (is_wp_error($response) || wp_remote_retrieve_response_code($response) !== 200) {
        error_log('Uptime Robot API error: ' . print_r($response, true)); // Log the error
        return; // Exit the function if there's an error
    }

    // Decode the API response into a PHP array
    $data = json_decode(wp_remote_retrieve_body($response), true);

    // Check if the response contains valid monitor data
    if (empty($data['monitors']) || !isset($data['monitors'][0]['custom_uptime_ratio'])) {
        error_log('Uptime Robot API returned invalid data: ' . print_r($data, true)); // Log invalid data
        return; // Exit the function if data is invalid
    }

    // Retrieve the site status from the API response
    $site_status = $data['monitors'][0]['status'];

    // Map the Uptime Robot status to custom labels
    $status_label = match ($site_status) {
        2 => 'success',   // Site is up
        9 => 'outage',    // Site is down
        8 => 'incident',  // Site seems down (store as "incident")
        0 => 'unknown',   // Site is paused (store as "unknown")
        1 => 'unknown',   // Site is not checked yet (store as "unknown")
        default => 'unknown' // Default to "unknown"
    };

    // Retrieve the uptime percentage for the last day
    $uptime_percentage = (float) $data['monitors'][0]['custom_uptime_ratio'];

    // Generate today's date in 'dd-mm-yyyy' format
    $today = date('d-m-Y');

    // Check if a WordPress post with today's date as the title already exists
    $existing_post = get_page_by_title($today, OBJECT, 'post');

    if (!$existing_post) {
        // Create a new post if it doesn't exist
        $post_id = wp_insert_post([
            'post_title'   => sanitize_text_field($today), // Set the post title to today's date
            'post_content' => '', // Leave post content empty
            'post_status'  => 'publish', // Set post status to 'publish'
            'post_author'  => 1, // Replace with the desired author ID
            'tags_input'   => [sanitize_text_field($status_label)], // Add the status as a tag
        ]);

        // Add the uptime percentage as a custom field if the post was created successfully
        if ($post_id) {
            add_post_meta($post_id, 'uptime_percentage', $uptime_percentage);
        }
    } else {
        // If the post already exists, update its tags and uptime percentage
        $post_id = $existing_post->ID;

        // Update the post's tags with the new status label
        wp_set_post_tags($post_id, [sanitize_text_field($status_label)], false);

        // Check if the 'uptime_percentage' custom field exists; if not, create it
        if (!get_post_meta($post_id, 'uptime_percentage', true)) {
            add_post_meta($post_id, 'uptime_percentage', $uptime_percentage);
        } else {
            // Update the existing 'uptime_percentage' custom field
            update_post_meta($post_id, 'uptime_percentage', $uptime_percentage);
        }
    }

    // Calculate the previous scheduled time for the cron job (5 minutes ago)
    $previous_scheduled_time = wp_next_scheduled('check_uptime_status') - 300; // Subtract 5 minutes

    // Update the post's modified date to match the previous scheduled time
    global $wpdb;
    $wpdb->update(
        $wpdb->posts, // WordPress posts table
        [
            'post_modified' => date('Y-m-d H:i:s', $previous_scheduled_time), // Local modified time
            'post_modified_gmt' => gmdate('Y-m-d H:i:s', $previous_scheduled_time) // GMT modified time
        ],
        ['ID' => $post_id], // Target the specific post ID
        ['%s', '%s'], // Data types for the values
        ['%d'] // Data type for the where clause
    );
});