How to build phalcon.so extension

1. Edit Dockerfile by setting PHP and Phalcon versions
2. docker build -t phalcon_ext_builder .
3. docker run -d --name phalcon_ext_builder phalcon_ext_builder
4. docker exec -it phalcon_ext_builder bash
5. ls /usr/local/lib/php/extensions -> no-debug-non-zts-20190902 is the dir you need (change "20190902" with another value if it differs)
6. exit
7. docker cp phalcon_ext_builder:/usr/local/lib/php/extensions/no-debug-non-zts-20190902/phalcon.so ./phalcon.so
8. docker stop phalcon_ext_builder && docker rm phalcon_ext_builder
9. docker image rm phalcon_ext_builder