Chocksy/Makefile

## readme.md

      
    Raw
  

              readme.md
            
          
    Docker for Rails + Puma + Nginx + Pagespeed + PostgreSQL + Redis + Memcached on Heroku

A detailed blog post is here: https://blog.epicpxls.com/docker-for-rails-puma-nginx-pagespeed-postgresql-redis-memcached-on-heroku-3272d88968f4
How to

Create a docker folder in the root of the app:

docker-compose.yml
docker

app

DockerFile
entrypoint.sh


web

DockerFile
nginx.conf
pagespeed.conf
perf.conf
routing.conf


Copy all the code from this gist and follow the blog post for more info.
Any comments or updates to this are welcome.

  
## app.DockerFile
# docker/app/DockerFile

# Base image / change this value to what ruby version you need.
FROM ruby:2.6.6
# Install dependencies
RUN apt-get update -qq
ENV LANG C.UTF-8

# Application dependencies
# We use an external Aptfile for that, stay tuned
COPY Aptfile /tmp/Aptfile
RUN DEBIAN_FRONTEND=noninteractive apt-get install -yq --no-install-recommends \
    build-essential libpq-dev nodejs \
    $(grep -Ev '^\s*#' /tmp/Aptfile | xargs) && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
    truncate -s 0 /var/log/*log

# Set an environment variable where the Rails app is installed to inside of Docker image:
ENV RAILS_ROOT /var/www/pxls
RUN mkdir -p $RAILS_ROOT
# Set working directory, where the commands will be ran:
WORKDIR $RAILS_ROOT
# Setting env up

# Add a script to be executed every time the container starts.
COPY docker/app/entrypoint.sh /usr/bin/
RUN chmod +x /usr/bin/entrypoint.sh
ENTRYPOINT ["entrypoint.sh"]

ENV RAILS_ENV='production'
ENV RACK_ENV='production'
# Adding gems
COPY Gemfile Gemfile
COPY Gemfile.lock Gemfile.lock
RUN bundle install --jobs 20 --retry 5 --without development test
# Adding project files
COPY . .
RUN bundle exec rake assets:precompile
EXPOSE 3000
CMD ["bundle", "exec", "puma", "-C", "config/puma.rb"]

## database.yml
# config/database.yml

development: &development
  <<: *default
  database: pxls_production
  username: postgres
  password:

test:
  <<: *development
  database: pxls_test
  username: postgres
  password:

production:
  <<: *default
  database: pxls_production
  username: postgres
  password:
  host: db

## docker-compose.yml
# How to run: https://docs.docker.com/compose/rails/
# docker-compose run web rails new . --force --database=postgresql --skip-bundle
# docker-compose build
# docker-compose up

version: '3.9'
services:
  app:
    build:
      context: .
      dockerfile: ./docker/app/DockerFile
    env_file: .env
    depends_on:
      - db
      - redis
      - memcached

  redis:
    image: redis:latest
    container_name: epicpxls-redis
    ports:
      - 6380:6379

  memcached:
    container_name: epicpxls-memcached
    image: memcached:latest
    ports:
      - 11212:11211

  db:
    image: postgres:10
    volumes:
      - ./tmp/db:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD", "pg_isready", "-U", "postgres"]
    environment:
      - POSTGRES_HOST_AUTH_METHOD=trust
  web:
    build:
      context: .
      dockerfile: ./docker/web/DockerFile
    depends_on:
      - app
    ports:
      - 80:80

## entrypoint.sh
# docker/app/entrypoint.sh

#!/bin/bash
set -e

# Remove a potentially pre-existing server.pid for Rails.
rm -f /app/tmp/pids/server.pid

# Then exec the container's main process (what's set as CMD in the Dockerfile).
exec "$@"

## Makefile
# Build the whole docker images.
# - we first copy all the variables from the figaro yml file to a .env file
# - then we build the docker images
# - we start the images
# - we create the database
# Call this with:
# - make build
build:
	@ruby docker/env_vars.rb
	@docker compose build
	@docker compose up -d
	@docker compose exec app bundle exec rails db:setup

# If you want to rebuild just one container then you can use:
# - make service=web rebuild
rebuild:
	@docker compose up --build --force-recreate --no-deps -d ${service}

# Used to start the docker images
start:
	@docker compose start

# Debug the application so we can use pry.
debug:
	@docker compose run --service-ports app

# Clean the docker instances (It restarts everything but does not remove the containers.)
clean:
	@docker compose down
	@docker system prune --volumes --force
	@rm -rf tmp/* || sudo rm -rf tmp/*
	@mkdir -p tmp/pids && touch tmp/pids/.keep

# If you want to execute a command on the container. Run this like this:
# - make bash
bash:
	@docker compose exec app bash

# See logs of the containers. Run with:
# - make logs
logs:
	@docker compose logs -f --tail=0 app

## nginx.conf
# This is a template. Referenced variables (e.g. $RAILS_ROOT) need
# to be rewritten with real values in order for this file to work.

events {
  use epoll;
  worker_connections 4096;
  multi_accept on;
}

http {
  server_tokens off;
  log_format l2met 'measure#nginx.service=$request_time request_id=$http_x_request_id';
  default_type application/octet-stream;
  include mime.types;
  sendfile on;
  tcp_nopush on;
  tcp_nodelay on;
  client_body_buffer_size 10K;
  client_header_buffer_size 4k;
  client_max_body_size 8m;
  large_client_header_buffers 2 4k;
  client_body_timeout 12;
  client_header_timeout 12;
  keepalive_timeout 15;
  send_timeout 10;

  upstream app_server {
    server 'app:3000';
  }

  server {
    # define your domain
    server_name _;
    # define the public application root
    root   $RAILS_ROOT/public;
    index  index.html;

    # Include performance configuration
    include /etc/nginx/perf.conf;
    # Include the pagespeed configuration
    include /etc/nginx/pagespeed.conf;
    # Include routing configuration
    include /etc/nginx/routing.conf;
  }
}

## pagespeed.conf
pagespeed on;

# Needs to exist and be writable by nginx.  Use tmpfs for best performance.
pagespeed FileCachePath /tmp/;

# All servers running a given release will have the same value for this header by default.
# If you would like to change the value reported, you can use the XHeaderValue directive to specify what to use instead:
pagespeed XHeaderValue "Powered by ngx_pagespeed";

# With PreserveUrlRelativity on, PageSpeed will keep URLs the way they were found.
pagespeed PreserveUrlRelativity on;

# HTML is case-insensitive, whereas XML and XHTML are not. Web performance Best Practices
# suggest using lowercase keywords, and PageSpeed can safely make that transformation in HTML documents.
pagespeed LowercaseHtmlNames on;
pagespeed AvoidRenamingIntrospectiveJavascript off;

# You can specify the maximum length (in bytes) of the content for PageSpeed to optimize.
# A setting of -1 means content of all lengths will be optimized, but risks server out-of-memory crashes.
pagespeed MaxCacheableContentLength -1;

# By using the CoreFilters set, as PageSpeed is updated with new filters, your site will get faster.
pagespeed RewriteLevel CoreFilters;

# If your site uses a non-standard attribute for URLs, PageSpeed won't know to rewrite them or the
# resources they reference. To identify them to PageSpeed, use the UrlValuedAttribute directive.
pagespeed UrlValuedAttribute img data-src image;

# By default, PageSpeed serves all HTML with Cache-Control: no-cache, max-age=0 because the
# transformations made to the page may not be cacheable for extended periods of time.
# pagespeed ModifyCachingHeaders off;
# pagespeed UseExperimentalJsMinifier on;

# Optimizations
## region CSS

### Inlines small CSS files into the HTML document.
pagespeed EnableFilters inline_css;

### Combines multiple CSS elements into one.
pagespeed EnableFilters combine_css;

### Moves CSS elements above <script> tags.
pagespeed EnableFilters move_css_above_scripts;

### Replace CSS tags with inline versions that include only the CSS used by the page.
pagespeed EnableFilters prioritize_critical_css;

### Rewrites CSS files to remove excess whitespace and comments, and, if enabled, rewrite or
### cache-extend images referenced in CSS files. In OptimizeForBandwidth mode, the minification
### occurs in-place without changing URLs.
pagespeed EnableFilters rewrite_css;

### Rewrite the CSS in style attributes by applying the configured rewrite_css filter to it.
pagespeed EnableFilters rewrite_style_attributes;

### Externalize large blocks of CSS into a cacheable file.
pagespeed EnableFilters outline_css;

### Moves CSS elements into the <head>.
pagespeed EnableFilters move_css_to_head;

### Rewrites resources referenced in any CSS file that cannot otherwise be parsed and minified.
pagespeed EnableFilters fallback_rewrite_css_urls;
## endregion

## region JS

### Convert synchronous use of Google Analytics API to asynchronous
pagespeed EnableFilters make_google_analytics_async;

### Externalize large blocks of JS into a cacheable file.
pagespeed EnableFilters outline_javascript;

### Adds source maps to rewritten JavaScript files.
pagespeed EnableFilters include_js_source_maps;

### Redirects JavaScript libraries to a JavaScript hosting service.
pagespeed EnableFilters canonicalize_javascript_libraries;

### Cache inlined resources in HTML5 local storage.
pagespeed EnableFilters local_storage_cache;

### Inlines small JS files into the HTML document.
pagespeed EnableFilters inline_javascript;

### Defers the execution of JavaScript in HTML until page load complete.
# pagespeed EnableFilters defer_javascript;
### Combines multiple script elements into one.
# pagespeed EnableFilters combine_javascript;
### Rewrites JavaScript files to remove excess whitespace and comments.
### In OptimizeForBandwidth mode, the minification occurs in-place without changing URLs.
# pagespeed EnableFilters rewrite_javascript;
## endregion

## region Images

### Works just like inline_preview_images, but uses smaller placeholder images and only serves them to mobile browsers.
pagespeed EnableFilters resize_mobile_images;

### Loads images when they become visible in the client viewport.
pagespeed EnableFilters lazyload_images;

### Adds width and height attributes to <img> tags that lack them.
pagespeed EnableFilters insert_image_dimensions;

### Replaces repeated inlined images with JavaScript that loads the image from the first occurence of the image.
pagespeed EnableFilters dedup_inlined_images;

### Uses inlined low-quality images as placeholders which will be replaced with original images once the web page is loaded.
# pagespeed EnableFilters inline_preview_images;
### Implied by rewrite_images. Replaces png and non-animated gif images with webp images on browsers that support the format.
# pagespeed EnableFilters convert_to_webp_lossless;
### Combine background images in CSS files into one sprite.
# pagespeed EnableFilters sprite_images;
### Optimizes images, re-encoding them, removing excess pixels, and inlining small images.
### In OptimizeForBandwidth mode, the minification occurs in-place without changing URLs.
# pagespeed EnableFilters rewrite_images;
### Makes images responsive by adding srcset with images optimized for various resolutions.
# pagespeed EnableFilters responsive_images;
### Implied by rewrite_images. Resizes images when the corresponding <img> tag specifies a smaller width and height.
# pagespeed EnableFilters resize_images;
## endregion

## region HTML

### Removes excess whitespace in HTML files (avoiding <pre>, <script>, <style>, and <textarea>).
pagespeed EnableFilters collapse_whitespace;

### Removes comments in HTML files (but not in inline JavaScript or CSS).
pagespeed EnableFilters remove_comments;

### Removes quotes around HTML attributes that are not lexically required.
pagespeed EnableFilters remove_quotes;

### Shortens URLs by making them relative to the base URL.
### !!! can't use it as it will trim the _path urls and that won't be good.
# pagespeed EnableFilters trim_urls;

### Add default types for <script> and <style> tags if the type attribute is not present and the
### page is not HTML5. The purpose of this filter is to help ensure that PageSpeed does not break HTML4 validation.
pagespeed EnableFilters pedantic;

### Perform browser-dependent in-place resource optimizations. (https://www.modpagespeed.com/doc/system#ipro)
pagespeed EnableFilters in_place_optimize_for_browser;

### Inserts <link rel="dns-prefetch" href="//www.example.com"> tags to reduce DNS resolution time.
pagespeed EnableFilters insert_dns_prefetch;

### Extends cache lifetime of CSS, JS, and image resources that have not otherwise been optimized, by signing URLs with a content hash.
pagespeed EnableFilters extend_cache;
## endregion

## region Authorization
pagespeed Domain *.epicpxls.com;
pagespeed Domain localhost;
## endregion

location ~ "\.pagespeed\.([a-z]\.)?[a-z]{2}\.[^.]{10}\.[^.]+" {
  add_header "" "";
}

location ~ "^/pagespeed_static/" { }
location ~ "^/ngx_pagespeed_beacon$" { }

## perf.conf
gzip on;
gzip_comp_level 5;
gzip_min_length 100;
gzip_vary on;
gzip_buffers 16 8k;
gzip_proxied any;
gzip_types *;
gzip_disable "MSIE [1-6]\.";

## routing.conf
# deny requests for files that should never be accessed
location ~ /\. {
  deny all;
  access_log off;
  log_not_found off;
  return 404;
}

location ~* ^.+\.(rb|log)$ {
  deny all;
}

location ~ ^/(robots.txt|humans.txt) {
  access_log off;
  log_not_found off;
  expires max;
}

# serve static (compiled) assets directly if they exist (for rails production)
location ~* ^.+\.(?:css|cur|js|jpe?g|gif|htc|ico|png|html|xml|otf|ttf|eot|woff|woff2|svg)$ {
  try_files $uri @rails;
  access_log off;
  # this does not work on the heroku buildpack we are using so we turn it off.
  # gzip_static on; # to serve pre-gzipped version
  expires max;
  add_header Cache-Control public;
  add_header Vary "Accept-Encoding";

  # No need to bleed constant updates. Send the all shebang in one fell swoop.
  tcp_nodelay off;

  # Set the OS file cache.
  open_file_cache max=3000 inactive=120s;
  open_file_cache_valid 45s;
  open_file_cache_min_uses 2;
  open_file_cache_errors off;

  # Some browsers still send conditional-GET requests if there's a
  # Last-Modified header or an ETag header even if they haven't
  # reached the expiry date sent in the Expires header.
  add_header Last-Modified "";
  add_header ETag "";
  break;
}

# send non-static file requests to the app server
location / {
  try_files $uri @rails;
}

location @rails {
  proxy_set_header X-Real-IP $remote_addr;
  proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header Host $http_host;
  proxy_redirect off;
  proxy_pass http://app_server;
}

## web.DockerFile
# docker/web/DockerFile

FROM crunchgeek/nginx-pagespeed

# establish where Nginx should look for files
ENV RAILS_ROOT /var/www/pxls
# Set our working directory inside the image
WORKDIR $RAILS_ROOT
# create log directory
RUN mkdir log
# copy over static assets
COPY public/ public/
# Copy Nginx config template
COPY docker/web/nginx.conf /tmp/docker.nginx/
COPY docker/web/perf.conf docker/web/routing.conf docker/web/pagespeed.conf /etc/nginx/
# substitute variable references in the Nginx config template for real values from the environment
# put the final config in its place
RUN envsubst '$RAILS_ROOT' < /tmp/docker.nginx/nginx.conf > /etc/nginx/nginx.conf
EXPOSE 80
# Use the "exec" form of CMD so Nginx shuts down gracefully on SIGTERM (i.e. `docker stop`)
CMD [ "nginx", "-g", "daemon off;" ]
	# docker/app/DockerFile

	# Base image / change this value to what ruby version you need.
	FROM ruby:2.6.6
	# Install dependencies
	RUN apt-get update -qq
	ENV LANG C.UTF-8

	# Application dependencies
	# We use an external Aptfile for that, stay tuned
	COPY Aptfile /tmp/Aptfile
	RUN DEBIAN_FRONTEND=noninteractive apt-get install -yq --no-install-recommends \
	build-essential libpq-dev nodejs \
	$(grep -Ev '^\s*#' /tmp/Aptfile \| xargs) && \
	apt-get clean && \
	rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
	truncate -s 0 /var/log/*log

	# Set an environment variable where the Rails app is installed to inside of Docker image:
	ENV RAILS_ROOT /var/www/pxls
	RUN mkdir -p $RAILS_ROOT
	# Set working directory, where the commands will be ran:
	WORKDIR $RAILS_ROOT
	# Setting env up

	# Add a script to be executed every time the container starts.
	COPY docker/app/entrypoint.sh /usr/bin/
	RUN chmod +x /usr/bin/entrypoint.sh
	ENTRYPOINT ["entrypoint.sh"]

	ENV RAILS_ENV='production'
	ENV RACK_ENV='production'
	# Adding gems
	COPY Gemfile Gemfile
	COPY Gemfile.lock Gemfile.lock
	RUN bundle install --jobs 20 --retry 5 --without development test
	# Adding project files
	COPY . .
	RUN bundle exec rake assets:precompile
	EXPOSE 3000
	CMD ["bundle", "exec", "puma", "-C", "config/puma.rb"]
	# config/database.yml

	development: &development
	<<: *default
	database: pxls_production
	username: postgres
	password:

	test:
	<<: *development
	database: pxls_test
	username: postgres
	password:

	production:
	<<: *default
	database: pxls_production
	username: postgres
	password:
	host: db
	# How to run: https://docs.docker.com/compose/rails/
	# docker-compose run web rails new . --force --database=postgresql --skip-bundle
	# docker-compose build
	# docker-compose up

	version: '3.9'
	services:
	app:
	build:
	context: .
	dockerfile: ./docker/app/DockerFile
	env_file: .env
	depends_on:
	- db
	- redis
	- memcached

	redis:
	image: redis:latest
	container_name: epicpxls-redis
	ports:
	- 6380:6379

	memcached:
	container_name: epicpxls-memcached
	image: memcached:latest
	ports:
	- 11212:11211

	db:
	image: postgres:10
	volumes:
	- ./tmp/db:/var/lib/postgresql/data
	healthcheck:
	test: ["CMD", "pg_isready", "-U", "postgres"]
	environment:
	- POSTGRES_HOST_AUTH_METHOD=trust
	web:
	build:
	context: .
	dockerfile: ./docker/web/DockerFile
	depends_on:
	- app
	ports:
	- 80:80
	# docker/app/entrypoint.sh

	#!/bin/bash
	set -e

	# Remove a potentially pre-existing server.pid for Rails.
	rm -f /app/tmp/pids/server.pid

	# Then exec the container's main process (what's set as CMD in the Dockerfile).
	exec "$@"
	# Build the whole docker images.
	# - we first copy all the variables from the figaro yml file to a .env file
	# - then we build the docker images
	# - we start the images
	# - we create the database
	# Call this with:
	# - make build
	build:
	@ruby docker/env_vars.rb
	@docker compose build
	@docker compose up -d
	@docker compose exec app bundle exec rails db:setup

	# If you want to rebuild just one container then you can use:
	# - make service=web rebuild
	rebuild:
	@docker compose up --build --force-recreate --no-deps -d ${service}

	# Used to start the docker images
	start:
	@docker compose start

	# Debug the application so we can use pry.
	debug:
	@docker compose run --service-ports app

	# Clean the docker instances (It restarts everything but does not remove the containers.)
	clean:
	@docker compose down
	@docker system prune --volumes --force
	@rm -rf tmp/* \|\| sudo rm -rf tmp/*
	@mkdir -p tmp/pids && touch tmp/pids/.keep

	# If you want to execute a command on the container. Run this like this:
	# - make bash
	bash:
	@docker compose exec app bash

	# See logs of the containers. Run with:
	# - make logs
	logs:
	@docker compose logs -f --tail=0 app
	# This is a template. Referenced variables (e.g. $RAILS_ROOT) need
	# to be rewritten with real values in order for this file to work.

	events {
	use epoll;
	worker_connections 4096;
	multi_accept on;
	}

	http {
	server_tokens off;
	log_format l2met 'measure#nginx.service=$request_time request_id=$http_x_request_id';
	default_type application/octet-stream;
	include mime.types;
	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	client_body_buffer_size 10K;
	client_header_buffer_size 4k;
	client_max_body_size 8m;
	large_client_header_buffers 2 4k;
	client_body_timeout 12;
	client_header_timeout 12;
	keepalive_timeout 15;
	send_timeout 10;

	upstream app_server {
	server 'app:3000';
	}

	server {
	# define your domain
	server_name _;
	# define the public application root
	root $RAILS_ROOT/public;
	index index.html;

	# Include performance configuration
	include /etc/nginx/perf.conf;
	# Include the pagespeed configuration
	include /etc/nginx/pagespeed.conf;
	# Include routing configuration
	include /etc/nginx/routing.conf;
	}
	}
	pagespeed on;

	# Needs to exist and be writable by nginx. Use tmpfs for best performance.
	pagespeed FileCachePath /tmp/;

	# All servers running a given release will have the same value for this header by default.
	# If you would like to change the value reported, you can use the XHeaderValue directive to specify what to use instead:
	pagespeed XHeaderValue "Powered by ngx_pagespeed";

	# With PreserveUrlRelativity on, PageSpeed will keep URLs the way they were found.
	pagespeed PreserveUrlRelativity on;

	# HTML is case-insensitive, whereas XML and XHTML are not. Web performance Best Practices
	# suggest using lowercase keywords, and PageSpeed can safely make that transformation in HTML documents.
	pagespeed LowercaseHtmlNames on;
	pagespeed AvoidRenamingIntrospectiveJavascript off;

	# You can specify the maximum length (in bytes) of the content for PageSpeed to optimize.
	# A setting of -1 means content of all lengths will be optimized, but risks server out-of-memory crashes.
	pagespeed MaxCacheableContentLength -1;

	# By using the CoreFilters set, as PageSpeed is updated with new filters, your site will get faster.
	pagespeed RewriteLevel CoreFilters;

	# If your site uses a non-standard attribute for URLs, PageSpeed won't know to rewrite them or the
	# resources they reference. To identify them to PageSpeed, use the UrlValuedAttribute directive.
	pagespeed UrlValuedAttribute img data-src image;

	# By default, PageSpeed serves all HTML with Cache-Control: no-cache, max-age=0 because the
	# transformations made to the page may not be cacheable for extended periods of time.
	# pagespeed ModifyCachingHeaders off;
	# pagespeed UseExperimentalJsMinifier on;

	# Optimizations
	## region CSS

	### Inlines small CSS files into the HTML document.
	pagespeed EnableFilters inline_css;

	### Combines multiple CSS elements into one.
	pagespeed EnableFilters combine_css;

	### Moves CSS elements above <script> tags.
	pagespeed EnableFilters move_css_above_scripts;

	### Replace CSS tags with inline versions that include only the CSS used by the page.
	pagespeed EnableFilters prioritize_critical_css;

	### Rewrites CSS files to remove excess whitespace and comments, and, if enabled, rewrite or
	### cache-extend images referenced in CSS files. In OptimizeForBandwidth mode, the minification
	### occurs in-place without changing URLs.
	pagespeed EnableFilters rewrite_css;

	### Rewrite the CSS in style attributes by applying the configured rewrite_css filter to it.
	pagespeed EnableFilters rewrite_style_attributes;

	### Externalize large blocks of CSS into a cacheable file.
	pagespeed EnableFilters outline_css;

	### Moves CSS elements into the <head>.
	pagespeed EnableFilters move_css_to_head;

	### Rewrites resources referenced in any CSS file that cannot otherwise be parsed and minified.
	pagespeed EnableFilters fallback_rewrite_css_urls;
	## endregion

	## region JS

	### Convert synchronous use of Google Analytics API to asynchronous
	pagespeed EnableFilters make_google_analytics_async;

	### Externalize large blocks of JS into a cacheable file.
	pagespeed EnableFilters outline_javascript;

	### Adds source maps to rewritten JavaScript files.
	pagespeed EnableFilters include_js_source_maps;

	### Redirects JavaScript libraries to a JavaScript hosting service.
	pagespeed EnableFilters canonicalize_javascript_libraries;

	### Cache inlined resources in HTML5 local storage.
	pagespeed EnableFilters local_storage_cache;

	### Inlines small JS files into the HTML document.
	pagespeed EnableFilters inline_javascript;

	### Defers the execution of JavaScript in HTML until page load complete.
	# pagespeed EnableFilters defer_javascript;
	### Combines multiple script elements into one.
	# pagespeed EnableFilters combine_javascript;
	### Rewrites JavaScript files to remove excess whitespace and comments.
	### In OptimizeForBandwidth mode, the minification occurs in-place without changing URLs.
	# pagespeed EnableFilters rewrite_javascript;
	## endregion

	## region Images

	### Works just like inline_preview_images, but uses smaller placeholder images and only serves them to mobile browsers.
	pagespeed EnableFilters resize_mobile_images;

	### Loads images when they become visible in the client viewport.
	pagespeed EnableFilters lazyload_images;

	### Adds width and height attributes to <img> tags that lack them.
	pagespeed EnableFilters insert_image_dimensions;

	### Replaces repeated inlined images with JavaScript that loads the image from the first occurence of the image.
	pagespeed EnableFilters dedup_inlined_images;

	### Uses inlined low-quality images as placeholders which will be replaced with original images once the web page is loaded.
	# pagespeed EnableFilters inline_preview_images;
	### Implied by rewrite_images. Replaces png and non-animated gif images with webp images on browsers that support the format.
	# pagespeed EnableFilters convert_to_webp_lossless;
	### Combine background images in CSS files into one sprite.
	# pagespeed EnableFilters sprite_images;
	### Optimizes images, re-encoding them, removing excess pixels, and inlining small images.
	### In OptimizeForBandwidth mode, the minification occurs in-place without changing URLs.
	# pagespeed EnableFilters rewrite_images;
	### Makes images responsive by adding srcset with images optimized for various resolutions.
	# pagespeed EnableFilters responsive_images;
	### Implied by rewrite_images. Resizes images when the corresponding <img> tag specifies a smaller width and height.
	# pagespeed EnableFilters resize_images;
	## endregion

	## region HTML

	### Removes excess whitespace in HTML files (avoiding <pre>, <script>, <style>, and <textarea>).
	pagespeed EnableFilters collapse_whitespace;

	### Removes comments in HTML files (but not in inline JavaScript or CSS).
	pagespeed EnableFilters remove_comments;

	### Removes quotes around HTML attributes that are not lexically required.
	pagespeed EnableFilters remove_quotes;

	### Shortens URLs by making them relative to the base URL.
	### !!! can't use it as it will trim the _path urls and that won't be good.
	# pagespeed EnableFilters trim_urls;

	### Add default types for <script> and <style> tags if the type attribute is not present and the
	### page is not HTML5. The purpose of this filter is to help ensure that PageSpeed does not break HTML4 validation.
	pagespeed EnableFilters pedantic;

	### Perform browser-dependent in-place resource optimizations. (https://www.modpagespeed.com/doc/system#ipro)
	pagespeed EnableFilters in_place_optimize_for_browser;

	### Inserts <link rel="dns-prefetch" href="//www.example.com"> tags to reduce DNS resolution time.
	pagespeed EnableFilters insert_dns_prefetch;

	### Extends cache lifetime of CSS, JS, and image resources that have not otherwise been optimized, by signing URLs with a content hash.
	pagespeed EnableFilters extend_cache;
	## endregion

	## region Authorization
	pagespeed Domain *.epicpxls.com;
	pagespeed Domain localhost;
	## endregion

	location ~ "\.pagespeed\.([a-z]\.)?[a-z]{2}\.[^.]{10}\.[^.]+" {
	add_header "" "";
	}

	location ~ "^/pagespeed_static/" { }
	location ~ "^/ngx_pagespeed_beacon$" { }
	gzip on;
	gzip_comp_level 5;
	gzip_min_length 100;
	gzip_vary on;
	gzip_buffers 16 8k;
	gzip_proxied any;
	gzip_types *;
	gzip_disable "MSIE [1-6]\.";
	# deny requests for files that should never be accessed
	location ~ /\. {
	deny all;
	access_log off;
	log_not_found off;
	return 404;
	}

	location ~* ^.+\.(rb\|log)$ {
	deny all;
	}

	location ~ ^/(robots.txt\|humans.txt) {
	access_log off;
	log_not_found off;
	expires max;
	}

	# serve static (compiled) assets directly if they exist (for rails production)
	location ~* ^.+\.(?:css\|cur\|js\|jpe?g\|gif\|htc\|ico\|png\|html\|xml\|otf\|ttf\|eot\|woff\|woff2\|svg)$ {
	try_files $uri @rails;
	access_log off;
	# this does not work on the heroku buildpack we are using so we turn it off.
	# gzip_static on; # to serve pre-gzipped version
	expires max;
	add_header Cache-Control public;
	add_header Vary "Accept-Encoding";

	# No need to bleed constant updates. Send the all shebang in one fell swoop.
	tcp_nodelay off;

	# Set the OS file cache.
	open_file_cache max=3000 inactive=120s;
	open_file_cache_valid 45s;
	open_file_cache_min_uses 2;
	open_file_cache_errors off;

	# Some browsers still send conditional-GET requests if there's a
	# Last-Modified header or an ETag header even if they haven't
	# reached the expiry date sent in the Expires header.
	add_header Last-Modified "";
	add_header ETag "";
	break;
	}

	# send non-static file requests to the app server
	location / {
	try_files $uri @rails;
	}

	location @rails {
	proxy_set_header X-Real-IP $remote_addr;
	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	proxy_set_header Host $http_host;
	proxy_redirect off;
	proxy_pass http://app_server;
	}
	# docker/web/DockerFile

	FROM crunchgeek/nginx-pagespeed

	# establish where Nginx should look for files
	ENV RAILS_ROOT /var/www/pxls
	# Set our working directory inside the image
	WORKDIR $RAILS_ROOT
	# create log directory
	RUN mkdir log
	# copy over static assets
	COPY public/ public/
	# Copy Nginx config template
	COPY docker/web/nginx.conf /tmp/docker.nginx/
	COPY docker/web/perf.conf docker/web/routing.conf docker/web/pagespeed.conf /etc/nginx/
	# substitute variable references in the Nginx config template for real values from the environment
	# put the final config in its place
	RUN envsubst '$RAILS_ROOT' < /tmp/docker.nginx/nginx.conf > /etc/nginx/nginx.conf
	EXPOSE 80
	# Use the "exec" form of CMD so Nginx shuts down gracefully on SIGTERM (i.e. `docker stop`)
	CMD [ "nginx", "-g", "daemon off;" ]