monitor.php

#! /usr/bin/env php
<?php

$command  = $argv[1];
$log_file = $argv[2];
$monitor_json = $argv[3];
if ( isset( $argv[4] ) ) {
	$urls_checked = $argv[4];
	$urls_checked = explode( ' ', $urls_checked );
	foreach ($urls_checked as $key => $value) {
		$position           = strpos( $value, "," );
		$urls_checked[$key] = substr( $value, $position + 1 );
	}
}
if ( isset( $argv[5] ) ) {
	$captain_id = $argv[5];
}

function time_elapsed_string( $datetime, $full = false ) {
	$now  = new DateTime();
	$ago  = new DateTime( $datetime );
	$diff = $now->diff( $ago );

	$diff->w  = floor( $diff->d / 7 );
	$diff->d -= $diff->w * 7;

	$string = array(
		'y' => 'year',
		'm' => 'month',
		'w' => 'week',
		'd' => 'day',
		'h' => 'hour',
		'i' => 'minute',
		's' => 'second',
	);
	foreach ( $string as $k => &$v ) {
		if ( $diff->$k ) {
			$v = $diff->$k . ' ' . $v . ( $diff->$k > 1 ? 's' : '' );
		} else {
			unset( $string[ $k ] );
		}
	}

	if ( ! $full ) {
		$string = array_slice( $string, 0, 1 );
	}
	return $string ? implode( ', ', $string ) . ' ago' : 'just now';
}

function process_log( $action = '' ) {

	global $log_file;
	$contents = file_get_contents( $log_file );
	$lines    = explode( "\n", $contents );
	$output   = array();
	$errors   = array();

	foreach ( $lines as $line ) {

		$json = json_decode( $line );

		// Check if JSON valid
		if ( json_last_error() !== JSON_ERROR_NONE ) {
			continue;
		}

		$record = (object) [
			'http_code'  => $json->http_code,
			'url'        => $json->url,
			'name'       => $json->name,
			'html_valid' => $json->html_valid,
		];

		// Check if HTML is valid
		if ( $json->html_valid == 'false' ) {
			// Append to errors
			$errors[] = $record;
			continue;
		}

		// Check if healthy
		if ( $json->http_code == '200' ) {
			$output[] = $line;
			continue;
		}

		// Check for redirects
		if ( $json->http_code == '301' ) {
			$output[] = $line;
			continue;
		}

		// Append to errors
		$errors[] = $record;
	}

	if ( $action == 'update' ) {

		// Update log file without errors
		$contents_updated = implode( "\n", $output );
		file_put_contents( $log_file, $contents_updated );

	}

	return $errors;
}

// Check command: Feed in log file, outputs error count
if ( $command == 'check' ) {

	echo count( process_log() );

}

// Process command: Feed in log file, outputs error urls and clean log file
if ( $command == 'process' ) {

	$errors  = process_log( 'update' );
	$urls    = array_column( $errors, 'url', 'name' );
	$results = "";

	// Return URLs,name with errors
	foreach ( $urls as $key => $value ) {
		$results = "$results $value,$key";
	}
	echo trim( $results );

}

// Generate command: Store errors in monitor.json and send email if needed
if ( $command == 'generate' ) {

	$notify_at    = array( '1 hour', '4 hour', '24 hour' );
	$log_errors   = process_log();
	$time_now     = date( 'U' );
	$errors       = array();
	$known_errors = array();
	$restored     = array();
	$warnings     = array();

	// Generate empty "/data/monitor.json" if needed
	if ( ! file_exists( $monitor_json ) ) {
		file_put_contents( $monitor_json, '[]' );
	}

	$monitor_records = json_decode( file_get_contents( $monitor_json ) );

	// Store errors in monitor.json
	foreach ( $log_errors as $log_error ) {

		$found = false;

		// See if url already in monitor.json
		foreach ( $monitor_records as $record ) {

			// increase count
			if ( $record->url == $log_error->url ) {
				 $record->check_count = $record->check_count + 1;
				 $record->updated_at  = $time_now;
				 $found               = true;
				 break;
			}
		}

		if ( ! $found ) {
			// Add to $monitor_records
			$monitor_records[] = (object) [
				'url'          => $log_error->url,
				'name'         => $log_error->name,
				'http_code'    => $log_error->http_code,
				'html_valid'   => $log_error->html_valid,
				'check_count'  => 1,
				'notify_count' => 0,
				'created_at'   => $time_now,
				'updated_at'   => $time_now,
			];

		}
	}

	// Loop through monitor records and update/remove to $errors[] as needed
	foreach ( $monitor_records as $key => $record ) {

		// If existing monitor record not in original check, just remove it.
		if ( ! in_array( $record->name, $urls_checked ) and $record->notify_count != 0 ) {
			unset( $monitor_records[ $key ] );
			continue;
		}

		// Check if online and remove from monitor.json
		if ( ! in_array( $record->url, array_column( $log_errors, 'url' ) ) ) {
			$time_ago   = date( 'F j, Y, g:i a', $record->created_at );
			$restored[] = "🟢 {$record->name} 🔗 {$record->url} offline since $time_ago\n";
			unset( $monitor_records[ $key ] );
			continue;
		}

		// Check if notifications count is exceeded, skip this record (Beyond 24hrs)
		if ( $record->notify_count >= count( $notify_at ) ) {
			$time_ago       = time_elapsed_string( '@' . $record->created_at );
			$known_errors[] = "{$record->http_code} response on {$record->name} 🔗 {$record->url} ⌚ $time_ago\n";
			continue;
		}

		// WordPress 5.2 bug causing random redirect loops with Kinsta cache on home page. If 301 found then sent a Kinsta purge cache.
		if ( $record->notify_count == 0 and $record->http_code == '301' ) {
			shell_exec( "captaincore ssh {$record->name} --command=\"wp kinsta cache purge --all\" --captain-id=$captain_id" );
		}

		if ( $record->notify_count == 0 ) {
			// If it's the first time then pass the time check
			$notify_time_check = $record->created_at;
		} else {
			// Otherwise calculate the time check based on $notify_count and $notify_at[]
			$key               = $record->notify_count - 1;
			$notify_time_check = strtotime( '-' . $notify_at[ $key ] );
		}

		// Check if "notify at" time is ready, otherwise skip this record
		if ( $record->created_at > $notify_time_check ) {
			$time_ago       = time_elapsed_string( '@' . $record->created_at );
			$known_errors[] = "{$record->http_code} response on {$record->name} 🔗 {$record->url} ⌚ $time_ago\n";
			continue;
		}

		// Check if HTML is valid
		if ( $record->html_valid == 'false' ) {
			$record->notify_count = $record->notify_count + 1;
			$time_ago             = time_elapsed_string( '@' . $record->created_at );
			$errors[]             = "{$record->http_code} response on {$record->name} 🔗 {$record->url} html is invalid ⌚ $time_ago\n";
			continue;
		}

		// Check for redirects
		if ( $record->http_code == '301' ) {
			$warnings[] = "{$record->http_code} response on {$record->name} 🔗 {$record->url}\n";
			continue;
		}

		// Append error to errors for email purposes
		$time_ago             = time_elapsed_string( '@' . $record->created_at );
		$errors[]             = "{$record->http_code} response on {$record->name} 🔗 {$record->url} ⌚ $time_ago\n";
		$record->notify_count = $record->notify_count + 1;

	}

	// Normalize your integer keys
	$monitor_records = array_values( $monitor_records );

	// Update monitor.json
	file_put_contents( $monitor_json, json_encode( $monitor_records, JSON_PRETTY_PRINT ) );

	// If errors then generate html
	if ( count( $errors ) > 0 ) {

		$html = '<strong>Errors</strong><br /><br />';

		foreach ( $errors as $error ) {
			$html .= trim( $error ) . "<br />\n";
		};

		if ( count( $warnings ) > 0 ) {
			$html .= '<br /><strong>Warnings</strong><br /><br />';
		}

		foreach ( $warnings as $warning ) {
			$html .= trim( $warning ) . "<br />\n";
		};

	}

	// If restored then generate html
	if ( count( $restored ) > 0 ) {

		$html = '<strong>Restored</strong><br /><br />';

		foreach ( $restored as $restore ) {
			$html .= trim( $restore ) . "<br />\n";
		};

	}

	// If errors or restored then append ongoing errors to the bottom then output html
	if ( count( $errors ) > 0 || count( $restored ) > 0 ) {

		if ( count( $known_errors ) > 0 ) {
			$html .= '<br /><strong>Ongoing Errors</strong><br /><br />';
		}

		foreach ( $known_errors as $known_error ) {
			$html .= trim( $known_error ) . "<br />\n";
		};

		echo $html;

	}
}