Running php script to execute hadoop command via shell on browser

Question

I have been trying to execute a hadoop command on terminal via shell_exec() in php and trying to run that script through url in browser. I have been facing a major problem:

When I try to run the following script in terminal:

<?php
    echo "Begin";
    echo shell_exec('hadoop fs -ls /');
    echo "End";
?>

It shows the desired result, the list of all items available on the root of HDFS. But when try to run the following script via url, it shows the following result:

url: localhost/myscript.php

BeginEnd

Nothing else! the script is working in terminal but not in browser.

When I change the script to :

<?php
    echo "Begin";
    echo shell_exec('ls /');
    echo "End";
?>

It shows all the items available in the root directory of local file system both in terminal and the browser.

I tried to change the command to check whether the script is running or not.

<?php
    echo "Begin";
    echo shell_exec('hadoop fs -mkdir /test');
    echo "End";
?>

When I run it through terminal using php myscript.php , it works and creates a directory in HDFS root directory. but when I try running it through browser via url with different directory name in the script, it just print BeginEnd without creating the directory at HDFS root.

[UPDATED]

When I access the apache log files, it says the following line after i load the url localhost/myscript.php :

[Thu Apr 07 10:04:07.187673 2016] [core:notice] [pid 1540] AH00094: Command line: '/usr/sbin/apache2'
sh: 1: hadoop: not found

When I try to execute the same script by Python using Flask. Both of the commands "mkdir" and "ls" works perfect and show the desired result in browser.

NOTE : When I execute python script for the desired work i do not use apache, i used Flask to host its own server.

What should be the problem ?

Answer 1

Take a look into your apache log files (error.log / access.log). The php.ini used for apache is not the same than the php.ini used with php-cli. Maybe you have an open_basedir restriction and you cannot run executable outside this directory.

http://phpsec.org/projects/phpsecinfo/tests/open_basedir.html

You can also verify these informations by making a test.php file with phpinfo function inside and browse it:

<? phpinfo() ; ?>