Installing ssh2 support in PHP

Most distribution has the SSH2 library packaged for PHP, but this is not the case for example if you are running CentOS with php55w installed.

In this case you need to manually install some prerequisites and compile it.

yum -y install libssh2-devel
yum -y install php55w-pear
yum -y install php55w-devel
pecl install ssh2-0.13

And then add extension=ssh2.so to php.ini and restart httpd