My case is similar to PHP shell_exec running a shellscript with ssh but not the same.
Situation: I exchanged ssh-keys between the 2 servers, switched to the www-data user and connecting to the 2nd server via SSH works without password.
Test 1: ssh user@10.8.0.6 Documents/run.sh list works fine when executed in shell
Test 2: Putting a simple PHP Exec in a PHP file works fine. It returns an Array and the Retval is 0
Test 3: Putting the exec into a "big" PHP script and calling it will result in Retval 255 (Fatal Error ?!?!?)
So at the moment I don't really understand why it isn't working. I tried to figure out more details about the retval 255 but didn't get far.
The difference must be somewhere in PHP5 vs PHP5 cli. But before I had to use OpenVPN it worked fine also via normal Apache call.
