$ docker logs --details mymagento2docker_nginx_1
 2016/10/04 19:18:31 [crit] 7#7: *2 connect() to unix:/var/run/php/php7.0-fpm.sock failed (2: No such file or directory) while connecting to upstream, client: 172.17.0.1, server: magento2.docker, request: "GET / HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.0-fpm.sock:", host: "magento2.docker"
 172.17.0.1 - - [04/Oct/2016:19:18:31 +0000] "GET / HTTP/1.1" 502 575 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36" "-"

$ docker-compose ps
            Name                          Command             State                   Ports
--------------------------------------------------------------------------------------------------
mymagento2docker_app_1          true                          Exit 0
mymagento2docker_data_1         docker-entrypoint.sh true     Exit 0
mymagento2docker_mysql_1        docker-entrypoint.sh mysqld   Up       0.0.0.0:3306->3306/tcp
mymagento2docker_nginx_1        nginx -g daemon off;          Up       443/tcp, 0.0.0.0:80->80/tcp
mymagento2docker_php_1          php-fpm                       Up       9000/tcp
mymagento2docker_phpmyadmin_1   /run.sh phpmyadmin            Up       0.0.0.0:8080->80/tcp

$ docker exec -it mymagento2docker_php_1 /bin/bash
root@e220b07a7124:/var/www/html# php -v
PHP 7.0.11 (cli) (built: Sep 23 2016 21:47:48) ( NTS )
Copyright (c) 1997-2016 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies

root@e220b07a7124:/var/www/html# ls /var/run/php
ls: cannot access /var/run/php: No such file or directory

root@e220b07a7124:/var/www/html# ls /var/run/
exim4  lock  utmp

root@e220b07a7124:/var/www/html# find / -name "*sock"
/sys/devices/virtual/misc/vsock
/sys/class/misc/vsock
/sys/module/vsock
/sys/module/hv_sock

root@e220b07a7124:/var/www/html# find / -type d -path /var/www/html -prune -o -name "php"
/usr/local/lib/php
/usr/local/etc/php
/usr/local/include/php
/usr/local/bin/php
/usr/local/php
/usr/local/php/php
/var/www/html

├── docker-compose.yml
├── magento2
│   ├── [Lots ommited...]
│   ├── [Lots ommited...]
├── nginx
│   ├── Dockerfile
│   ├── default.conf
│   └── nginx.conf
└── php
    └── Dockerfile

# http://tech.osteel.me/posts/2015/12/18/from-vagrant-to-docker-how-to-use-docker-for-local-web-development.html#installation
# composer create-project --ignore-platform-reqs --repository-url=https://repo.magento.com/ magento/project-community-edition magento2

nginx:
    build: ./nginx/
    ports:
        - 80:80
    links:
        - php
    volumes_from:
        - app

php:
    build: ./php/
    expose:
        - 9000
    links:
        - mysql
    volumes_from:
        - app

app:
    image: php:7.0-fpm
    volumes:
        - ./magento2:/var/www/html
    command: "true"

mysql:
    image: mysql:latest
    volumes_from:
        - data
    ports:
        - "3306:3306"
    environment:
        MYSQL_ROOT_PASSWORD: mage2
        MYSQL_DATABASE: mage2
        MYSQL_USER: mage2
        MYSQL_PASSWORD: mage2

data:
    image: mysql:latest
    volumes:
        - /var/lib/mysql
    command: "true"

phpmyadmin:
    image: phpmyadmin/phpmyadmin
    ports:
        - 8080:80
    links:
        - mysql
    environment:
        PMA_HOST: mysql

FROM php:7.0-fpm

# Install dependencies
RUN apt-get update
  && apt-get install -y
    cron
    libfreetype6-dev
    libicu-dev
    libjpeg62-turbo-dev
    libmcrypt-dev
    libpng12-dev
    libxslt1-dev

# Configure the gd library
RUN docker-php-ext-configure
  gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/

# Install required PHP extensions
RUN docker-php-ext-install
  gd
  intl
  mbstring
  mcrypt
  pdo_mysql
  xsl
  zip
  soap

# Install the 2.4 version of xdebug that's compatible with php7
RUN pecl install -o -f xdebug-2.4.0

FROM nginx:latest

RUN rm -f /etc/nginx/conf.d/*
RUN rm -f /etc/nginx/nginx.conf
COPY ./nginx.conf /etc/nginx/
COPY ./default.conf /etc/nginx/conf.d/default.conf

# Example configuration:
upstream fastcgi_backend {
    #  use tcp connection
    server   unix:/var/run/php/php7.0-fpm.sock;
    # I"ve also tried the below...
    # server  127.0.0.1:9000;
    # server  fpm:9000;
}

server {
    listen 80;

    server_name magento2.docker;
    set $MAGE_ROOT /var/www/html/;
    set $MAGE_MODE default;

    root $MAGE_ROOT/pub;

    index index.php;
    autoindex off;
    charset off;

    add_header 'X-Content-Type-Options' 'nosniff';
    add_header 'X-XSS-Protection' '1; mode=block';

    location /setup {
        root $MAGE_ROOT;
        location ~ ^/setup/index.php {
            fastcgi_pass   fastcgi_backend;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            include        fastcgi_params;
        }

        location ~ ^/setup/(?!pub/). {
            deny all;
        }

        location ~ ^/setup/pub/ {
            add_header X-Frame-Options "SAMEORIGIN";
        }
    }

    location /update {
        root $MAGE_ROOT;

        location ~ ^/update/index.php {
            fastcgi_split_path_info ^(/update/index.php)(/.+)$;
            fastcgi_pass   fastcgi_backend;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            fastcgi_param  PATH_INFO        $fastcgi_path_info;
            include        fastcgi_params;
        }

        # deny everything but index.php
        location ~ ^/update/(?!pub/). {
            deny all;
        }

        location ~ ^/update/pub/ {
            add_header X-Frame-Options "SAMEORIGIN";
        }
    }

    location / {
        try_files $uri $uri/ /index.php?$args;
    }

    location /pub {
        location ~ ^/pub/media/(downloadable|customer|import|theme_customization/.*.xml) {
            deny all;
        }
        alias $MAGE_ROOT/pub;
        add_header X-Frame-Options "SAMEORIGIN";
    }

    location /static/ {
        if ($MAGE_MODE = "production") {
            expires max;
        }
        location ~ ^/static/version {
            rewrite ^/static/(versiond*/)?(.*)$ /static/$2 last;
        }

        location ~* .(ico|jpg|jpeg|png|gif|svg|js|css|swf|eot|ttf|otf|woff|woff2)$ {
            add_header Cache-Control "public";
            add_header X-Frame-Options "SAMEORIGIN";
            expires +1y;

            if (!-f $request_filename) {
                rewrite ^/static/(versiond*/)?(.*)$ /static.php?resource=$2 last;
            }
        }
        location ~* .(zip|gz|gzip|bz2|csv|xml)$ {
            add_header Cache-Control "no-store";
            add_header X-Frame-Options "SAMEORIGIN";
            expires    off;

            if (!-f $request_filename) {
               rewrite ^/static/(versiond*/)?(.*)$ /static.php?resource=$2 last;
            }
        }
        if (!-f $request_filename) {
            rewrite ^/static/(versiond*/)?(.*)$ /static.php?resource=$2 last;
        }
        add_header X-Frame-Options "SAMEORIGIN";
    }

    location /media/ {
        try_files $uri $uri/ /get.php?$args;

        location ~ ^/media/theme_customization/.*.xml {
            deny all;
        }

        location ~* .(ico|jpg|jpeg|png|gif|svg|js|css|swf|eot|ttf|otf|woff|woff2)$ {
            add_header Cache-Control "public";
            add_header X-Frame-Options "SAMEORIGIN";
            expires +1y;
            try_files $uri $uri/ /get.php?$args;
        }
        location ~* .(zip|gz|gzip|bz2|csv|xml)$ {
            add_header Cache-Control "no-store";
            add_header X-Frame-Options "SAMEORIGIN";
            expires    off;
            try_files $uri $uri/ /get.php?$args;
        }
        add_header X-Frame-Options "SAMEORIGIN";
    }

    location /media/customer/ {
        deny all;
    }

    location /media/downloadable/ {
        deny all;
    }

    location /media/import/ {
        deny all;
    }

    location ~ cron.php {
        deny all;
    }

    location ~ (index|get|static|report|404|503).php$ {
        try_files $uri =404;
        fastcgi_pass   fastcgi_backend;

        fastcgi_param  PHP_FLAG  "session.auto_start=off n suhosin.session.cryptua=off";
        fastcgi_param  PHP_VALUE "memory_limit=512M n max_execution_time=600";
        fastcgi_read_timeout 600s;
        fastcgi_connect_timeout 600s;
        fastcgi_param  MAGE_MODE $MAGE_MODE;

        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        fastcgi_params;
    }
}

error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
  worker_connections 1024;
}

http {
  include /etc/nginx/mime.types;
  default_type application/octet-stream;

  log_format main '$remote_addr - $remote_user [$time_local] "$request" '
          '$status $body_bytes_sent "$http_referer" '
          '"$http_user_agent" "$http_x_forwarded_for"';

  access_log /var/log/nginx/access.log main;

  sendfile on;
  tcp_nopush on;

  keepalive_timeout 65;

  fastcgi_buffers 8 16k;
  fastcgi_buffer_size 32k;
  fastcgi_connect_timeout 300;
  fastcgi_send_timeout 300;
  fastcgi_read_timeout 300;

  gzip on;

  include /etc/nginx/conf.d/*;
}