PHP 7 runtime errors/exceptions handling done right

php-error-logging.php

<?php

/**
 * Simple, custom, bulletproof PHP 7 runtime errors/exceptions handling done right (I hope so :).
 * By handling I mean logging to systemd journal or stderr, and die if any exception,
 * error, warning, and even notice or strict occurs. This is not all-in-one
 * or an ultimate solusion, but a good base to start with.
 * Logs go to stderr or systemd journal (recommended, but optional). Systemd extension
 * for PHP can be found at https://github.com/systemd/php-systemd
 */

# Available log levels
#---------------------
# LOG_EMERG (0)
# LOG_ALERT (1)
# LOG_CRIT (2)
# LOG_ERR (3)
# LOG_WARNING (4)
# LOG_NOTICE (5)
# LOG_INFO (6)
# LOG_DEBUG (7)

# Where to log; journal (systemd) or php://stderr (or a file)
if (!defined('MY_ERROR_LOG')) {
    define('MY_ERROR_LOG', 'php://stderr');
}

# Log level. Debug level logs stack traces
if (!defined('MY_LOG_LEVEL')) {
    define('MY_LOG_LEVEL', LOG_DEBUG);
}

# Log app name (facility, identifier)
if (!defined('MY_LOG_FACILITY')) {
    define('MY_LOG_FACILITY', 'spblue');
}

# Log date format (not used with systemd)
if (!defined('MY_LOG_DATE_FORMAT')) {
    define('MY_LOG_DATE_FORMAT', 'Y-m-d H:i:s');
}

# Report everything. This is important
error_reporting(E_ALL);

/**
 * Pretty exceptions format
 */
function formatException(Throwable $e)
{
    $type = get_class($e);
    if ($e instanceof ErrorException) {
        # Only ErrorException has PHP severity
        switch ($e->getSeverity()) {
            case E_NOTICE: $type = 'PHP Notice'; break;
            case E_WARNING: $type = 'PHP Warning'; break;
            case E_STRICT: $type = 'PHP Strict'; break;
            default: $type = 'PHP Error';
        }
    }
    $message = 'We have a problem: [%s]: %s, in file %s at line %s.';
    $args = [
        $type,
        $e->getMessage() ?: '<no message>',
        $e->getFile() ?: '<unknown file>',
        $e->getLine() ?: '<unknown line>'
    ];
    if (MY_LOG_LEVEL >= LOG_DEBUG) {
        $message .= "\nStack trace:\n%s";
        $args[] = $e->getTraceAsString();
    }
    return sprintf($message, ...$args);
}

/**
 * Useful alias
 */
function logException(Throwable $e)
{
    logError(formatException($e));
}

/**
 * Be strict. None shall pass.
 */
set_error_handler(function($severity, $message, $file, $line) {
    if (error_reporting() !== 0) { // <== Error was NOT suppressed with @. Log this, we will die
        // This is a very neat way to have consistent message with stack trace
        logException(new ErrorException($message, 0, $severity, $file, $line));
    }
    if (error_reporting() === 0) {
        return true; // Error suppressed with @. Continue script execution and don't fire default PHP handler
    }
    die();
}, E_ALL);

/**
 * Log, log and log (and die)
 */
set_exception_handler(function(Throwable $e) {
    // As simple as that
    logException($e);
    die();
});

function logError($message, ...$args)
{
    errorLog(LOG_ERR, $message, ...$args);
}

function logWarning($message, ...$args)
{
    errorLog(LOG_WARNING, $message, ...$args);
}

function logNotice($message, ...$args)
{
    errorLog(LOG_NOTICE, $message, ...$args);
}

function logInfo($message, ...$args)
{
    errorLog(LOG_INFO, $message, ...$args);
}

function logDebug($message, ...$args)
{
    errorLog(LOG_DEBUG, $message, ...$args);
}

function logLevelToString($level)
{
    $type = null;
    switch ($level) {
        case LOG_DEBUG: $type = 'DEBUG'; break;
        case LOG_INFO: $type = 'INFO'; break;
        case LOG_NOTICE: $type = 'NOTICE'; break;
        case LOG_WARNING: $type = 'WARNING'; break;
        default: $type = 'ERROR'; break;
    }
    return $type;
}

/**
 * Log error to php://stderr or systemd journal. Die with a reason
 * if something goes wrong.
 */
function errorLog($level, $message, ...$args)
{
    $level = max(min(LOG_DEBUG, (int) $level), LOG_EMERG);
    if ($level > MY_LOG_LEVEL) {
        return;
    }
    if (!empty($args) and false != $m = @sprintf($message, ...$args)) {
        $message = $m;
    }
    if (MY_ERROR_LOG === 'journal' or MY_ERROR_LOG === 'systemd') {
        $logTo = extension_loaded('systemd') ? 'journal' : 'php://stderr';
    } else {
        $logTo = MY_ERROR_LOG;
    }
    if ($logTo === 'journal') {
        $args = [
            sprintf('MESSAGE=%s', $message),
            sprintf('PRIORITY=%s', $level),
            sprintf('SYSLOG_IDENTIFIER=%s', MY_LOG_FACILITY)
        ];
        if (!sd_journal_send(...$args)) {
            die('Unable to log to systemd journal');
        }
    } else {
        $message = sprintf(
            "[%s] [%s] %s: %s\n",
            date(MY_LOG_DATE_FORMAT),
            MY_LOG_FACILITY,
            logLevelToString($level),
            $message
        );
        if (false !== $file = @fopen($logTo, 'a')) {
            if (!fwrite($file, $message)) {
                fclose($file);
                die('Unable to write to log file');
            }
            fclose($file);
        } else {
            die('Unable to open log file');
        }
    }
}