RUN docker-php-source extract \
&& mkdir -p /usr/src/php/ext/ssh2 \
&& curl -fsSL https://github.com/php/pecl-networking-ssh2/archive/master.tar.gz | tar xvz -C /usr/src/php/ext/ssh2 --strip 1 \
&& docker-php-ext-install ssh2 \
&& docker-php-source delete