#Nginx + PHP-fpm This repo forms the basis of an easy way to setup horizontally scaling PHP-fpm servers, behind an Nginx load-balancer

##Dependencies ###docker-compose I use docker-compose to link the containers.

I had trouble using this on OSX, but found some useful information here: docker/compose#271. Note that I installed Docker using Kitematic.

These issues seemed to have been fixed with some recent updates of Docker to bundle all software into the Docker Toolbox. Everything worked perfectly with the Toolbox on a fresh install.

###Docker Volume You also need to have a docker volume contianer, (I've called mine src) to mount the files in /app and replicate across each of the containers. You can read more about volumes here.

To create the one required here, run:

docker create -v /path/to/docker/app:/src --name src nginx /bin/true

where /path/to/docker/app is the absolute path to whatever files you want to mount on your host machine, i.e. a php app. You can link to /docker/app in this repositiory to see how it works. /src after the colon specifies the absolute path of where these files are mounted to within each container.

##Usage Simply run docker-compose up -d from the root of the directory. It will build images and then run services of everything specified in the docker-compose.yml file.

##Notes

• To maintain predictability for the docker scale command, docker prefixes docker_ to the start of container names specified in the .yml file and appends _1 to the end of each instance. For example, the name php1 will appear as a container docker_php1_1. This will appear as an entry in the hosts file of docker_server_1 for a maintanable reference (otherwise the reference would be a random hash).
• Defining the docker-compose.yml with one php definition and intending to call docker-compose scale php=3 (which would create 3 instances, called docker_php_1, docker_php_2 and docker_php_3) after startup will cause nginx to fail (and so the instance won't start) becuase it would't have a reference to docker_php_2 and docker_php_3 as there won't be entries in the hosts file yet. That's why I defined them all indivitually. See first TODO below.
• For it to be possible to have Nginx and PHP-fpm on different servers, you need to replicate, identically, the file structure of your application, across all instances. Nginx simply sends the filename to the PHP-fpm server, and not the file itself.

##TODO

1. Figure out how to incorperate docker-compose scale php=3 and remove the duplication of php service declarations in the docker-compose.yml file. To do this, we need to be able to configure the servers in nginx's upstream directive in nginx.conf.