Where to Unset or change $_SERVER['LD_LIBRARY_PATH']?

Question

I have an Apache 2.4 proxying to PHP7.4.4 php-fpm and I am trying to hide or unset the $_SERVER['LD_LIBRARY_PATH'] variable.

How do I change or get rid of this variable $_SERVER['LD_LIBRARY_PATH'] in the PHP output?

Assume that apache2.4 is installed to /apache24.

==userX-fpm-pool.conf==
[userX]
user = userX
group = userX
listen = 127.0.0.1:9003
clear_env = yes
env['LD_LIBRARY_PATH'] = /fakepath

==php.ini==
variables_order = "GPCS"

==userX-vhost.conf==
<VirtualHost *:80>
    ServerName userX.xxxxxx.com

    ServerAdmin webmaster@localhost
    DocumentRoot /userX/home/www

    UnsetEnv LD_LIBRARY_PATH

    <Directory /userX/home/www>
            Options Indexes FollowSymLinks
            DirectoryIndex index.php index.html
            Require all granted
            AllowOverride All
    </Directory>

    ProxyPassMatch "^/(.*\.php(/.*)?)$" "fcgi://127.0.0.1:9003/"
</VirtualHost>

==index.php==
<?php
print_r($_ENV);
print_r($_SERVER);

The curl output:

curl -H "Host: userX.xxxxxx.com" http://127.0.0.1
Array
(
)
Array
(
    [LD_LIBRARY_PATH] => /apache24/lib --> How do I change or get rid of this variable?
    [USER] => userX
    [HOME] => /home
    [SCRIPT_NAME] => /index.php
    [REQUEST_URI] => /
    [QUERY_STRING] =>
    [REQUEST_METHOD] => GET
    [SERVER_PROTOCOL] => HTTP/1.1
    [GATEWAY_INTERFACE] => CGI/1.1
    [REMOTE_PORT] => 49248
    [SCRIPT_FILENAME] => //index.php
    [SERVER_ADMIN] => webmaster@localhost
    [CONTEXT_DOCUMENT_ROOT] => /userX/home/www
    [CONTEXT_PREFIX] =>
    [REQUEST_SCHEME] => http
    [DOCUMENT_ROOT] => /userX/home/www
    [REMOTE_ADDR] => 127.0.0.1
    [SERVER_PORT] => 80
    [SERVER_ADDR] => 127.0.0.1
    [SERVER_NAME] => userX.xxxxxx.com
    [SERVER_SOFTWARE] => Apache/2.4.43 (Unix) OpenSSL/1.1.1 PHP/7.4.4
    [SERVER_SIGNATURE] =>
    [PATH] => /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
    [HTTP_ACCEPT] => */*
    [HTTP_USER_AGENT] => curl/7.58.0
    [HTTP_HOST] => userX.xxxxxx.com
    [FCGI_ROLE] => RESPONDER
    [PHP_SELF] => /index.php
    [REQUEST_TIME_FLOAT] => 1587830093.9565
    [REQUEST_TIME] => 1587830093
)

Answer 1

Don't "print_r($_SERVER);", and it won't appear in your output. It's an environment variable set when Apache (= the server) was started. You can manipulate it in the Apache startup scripts, or the Apache configuration. If you get rid of it, don't be surprised if Apache doesn't start anymore.

Answer 2

Solved it. The solution is to comment off the LD_LIBRARY_PATH setting and export lines in envvars file in the bin directory of httpd-2.4.3 and then changing the FPM pool config file to the desired env value. Since the lib/ directory is for external linkage and I don't need it, apachectl starts fine. The only caveat is that ./apachectl restart doesn't work, you have to manually do a ./apachectl stop and then ./apachectl start for the changes to take effect.

==envvars==
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
#
# envvars-std - default environment variables for apachectl
#
# This file is generated from envvars-std.in
#
#if test "x$LD_LIBRARY_PATH" != "x" ; then
#  LD_LIBRARY_PATH="/apache24/lib:$LD_LIBRARY_PATH"
#else
#  LD_LIBRARY_PATH="/apache24/lib"
#fi
#export LD_LIBRARY_PATH
#

==userX-fpm-pool.conf==
[userX]
user = userX
group = userX
listen = 127.0.0.1:9003
clear_env = yes
env['LD_LIBRARY_PATH'] = /fakepath


root@instance:/apache24/bin# ./apachectl stop && ./apachectl start

curl -H "Host: userX.xxxxxx.com" http://127.0.0.1
Array
(
)
Array
(
    [LD_LIBRARY_PATH] => /fakepath
    [USER] => userX
    [HOME] => /home
    [SCRIPT_NAME] => /index.php
    [REQUEST_URI] => /
    [QUERY_STRING] =>
    [REQUEST_METHOD] => GET
    [SERVER_PROTOCOL] => HTTP/1.1
    [GATEWAY_INTERFACE] => CGI/1.1
    [REMOTE_PORT] => 49348
    [SCRIPT_FILENAME] => //index.php
    [SERVER_ADMIN] => webmaster@localhost
    [CONTEXT_DOCUMENT_ROOT] => /userX/home/www
    [CONTEXT_PREFIX] =>
    [REQUEST_SCHEME] => http
    [DOCUMENT_ROOT] => /userX/home/www
    [REMOTE_ADDR] => 127.0.0.1
    [SERVER_PORT] => 80
    [SERVER_ADDR] => 127.0.0.1
    [SERVER_NAME] => userX.xxxxxx.com
    [SERVER_SOFTWARE] => Apache/2.4.43 (Unix) OpenSSL/1.1.1 PHP/7.4.4
    [SERVER_SIGNATURE] =>
    [PATH] => /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
    [HTTP_ACCEPT] => */*
    [HTTP_USER_AGENT] => curl/7.58.0
    [HTTP_HOST] => userX.xxxxxx.com
    [FCGI_ROLE] => RESPONDER
    [PHP_SELF] => /index.php
    [REQUEST_TIME_FLOAT] => 1587866614.9455
    [REQUEST_TIME] => 1587866614
)