wp-cli PHP Notice after moving server behind load balancer

Question

After setting up an Amazon Elastic Load Balancer, where SSL terminates, I was getting Mixed Content errors on the site, until I added the following line to wp-config.php.

if (strpos($_SERVER['HTTP_X_FORWARDED_PROTO'], 'https') !== false)
$_SERVER['HTTPS']='on';

While this fixed the Mixed Content errors, now I get this PHP Notice after using wp-cli:

PHP Notice:  Undefined index: HTTP_X_FORWARDED_PROTO in phar:///opt/bitnami/apps/wordpress/bin/wp-cli.phar/vendor/wp-cli/wp-cli/php/WP_CLI/Runner.php(1169) : eval()'d code on line 81

What should I do?

Answer 1

Check if isset() first. It will not always be set (that is what the undefined index is referring to):

I took this from user temuraru

$isSecure = false;
if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') {
    $isSecure = true;
}
elseif (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https' || !empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] == 'on') {
    $isSecure = true;
}
$REQUEST_PROTOCOL = $isSecure ? 'https' : 'http';