Docker PHP-FPM 7.4 & Nginx 1.18 on Alpine Linux

Example PHP-FPM 7.4 & Nginx 1.18 setup for Docker, build on Alpine Linux. The image is only +/- 25MB large.

Repository: https://github.com/erseco/alpine-php7-webserver

• Built on the lightweight and secure Alpine Linux distribution
• Very small Docker image size (+/-25MB)
• Uses PHP 7.4 for better performance, lower cpu usage & memory footprint
• Multi-arch support: 386, amd64, arm/v6, arm/v7, arm64, ppc64le, s390x
• Optimized for 100 concurrent users
• Optimized to only use resources when there's traffic (by using PHP-FPM's ondemand PM)
• Use of runit instead of supervisord to reduce memory footprint
• The servers Nginx, PHP-FPM run under a non-privileged user (nobody) to make it more secure
• The logs of all the services are redirected to the output of the Docker container (visible with docker logs -f <container name>)
• Follows the KISS principle (Keep It Simple, Stupid) to make it easy to understand and adjust the image to your needs
• Also availabe in Apache flavour: erseco/alpine-php7-webserver:apache

Usage

Start the Docker container:

docker run -p 80:8080 erseco/alpine-php7-webserver

See the PHP info on http://localhost, or the static html page on http://localhost/test.html

Or mount your own code to be served by PHP-FPM & Nginx

docker run -p 80:8080 -v ~/my-codebase:/var/www/html erseco/alpine-php7-webserver

Adding additional daemons

You can add additional daemons (e.g. your own app) to the image by creating runit entries. You only have to write a small shell script which runs your daemon, and runit will keep it up and running for you, restarting it when it crashes, etc.

The shell script must be called run, must be executable, and is to be placed in the directory /etc/service/<NAME>.

Here's an example showing you how a memcached server runit entry can be made.

#!/bin/sh
### In memcached.sh (make sure this file is chmod +x):
# `chpst -u memcache` runs the given command as the user `memcache`.
# If you omit that part, the command will be run as root.
exec 2>&1 chpst -u memcache /usr/bin/memcached

### In Dockerfile:
RUN mkdir /etc/service/memcached
ADD memcached.sh /etc/service/memcached/run

Note that the shell script must run the daemon without letting it daemonize/fork it. Usually, daemons provide a command line flag or a config file option for that.

Running scripts during container startup

You can set your own scripts during startup, just add your scripts in /docker-entrypoint-init.d/. The scripts are run in lexicographic order.

All scripts must exit correctly, e.g. with exit code 0. If any script exits with a non-zero exit code, the booting will fail.

The following example shows how you can add a startup script. This script simply logs the time of boot to the file /tmp/boottime.txt.

#!/bin/sh
### In logtime.sh (make sure this file is chmod +x):
date > /tmp/boottime.txt

### In Dockerfile:
ADD logtime.sh /docker-entrypoint-init.d/logtime.sh

Configuration

In rootfs/etc/ you'll find the default configuration files for Nginx, PHP and PHP-FPM. If you want to extend or customize that you can do so by mounting a configuration file in the correct folder;

Nginx configuration:

docker run -v "`pwd`/nginx-server.conf:/etc/nginx/conf.d/server.conf" erseco/alpine-php7-webserver

PHP configuration:

docker run -v "`pwd`/php-setting.ini:/etc/php7/conf.d/settings.ini" erseco/alpine-php7-webserver

PHP-FPM configuration:

docker run -v "`pwd`/php-fpm-settings.conf:/etc/php7/php-fpm.d/server.conf" erseco/alpine-php7-webserver

Note; Because -v requires an absolute path I've added pwd in the example to return the absolute path to the current directory

## Environment variables

You can define the next environment variables to change values from NGINX and PHP

Server	Variable Name	Default	description
NGINX	client_max_body_size	2m	Sets the maximum allowed size of the client request body, specified in the “Content-Length” request header field.
PHP7	clear_env	no	Clear environment in FPM workers. Prevents arbitrary environment variables from reaching FPM worker processes by clearing the environment in workers before env vars specified in this pool configuration are added.
PHP7	allow_url_fopen	On	Enable the URL-aware fopen wrappers that enable accessing URL object like files. Default wrappers are provided for the access of remote files using the ftp or http protocol, some extensions like zlib may register additional wrappers.
PHP7	allow_url_include	Off	Allow the use of URL-aware fopen wrappers with the following functions: include(), include_once(), require(), require_once().
PHP7	display_errors	Off	Eetermine whether errors should be printed to the screen as part of the output or if they should be hidden from the user.
PHP7	file_uploads	On	Whether or not to allow HTTP file uploads.
PHP7	max_execution_time	0	Maximum time in seconds a script is allowed to run before it is terminated by the parser. This helps prevent poorly written scripts from tying up the server. The default setting is 30.
PHP7	max_input_time	-1	Maximum time in seconds a script is allowed to parse input data, like POST, GET and file uploads.
PHP7	max_input_vars	1000	Maximum number of input variables allowed per request and can be used to deter denial of service attacks involving hash collisions on the input variable names.
PHP7	memory_limit	128M	Maximum amount of memory in bytes that a script is allowed to allocate. This helps prevent poorly written scripts for eating up all available memory on a server. Note that to have no memory limit, set this directive to -1.
PHP7	post_max_size	8M	Max size of post data allowed. This setting also affects file upload. To upload large files, this value must be larger than upload_max_filesize. Generally speaking, memory_limit should be larger than post_max_size.
PHP7	upload_max_filesize	2M	Maximum size of an uploaded file.
PHP7	zlib.output_compression	On	Whether to transparently compress pages. If this option is set to "On" in php.ini or the Apache configuration, pages are compressed if the browser sends an "Accept-Encoding: gzip" or "deflate" header.

Note; Because -v requires an absolute path I've added pwd in the example to return the absolute path to the current directory

Adding composer

If you need Composer in your project, here's an easy way to add it.

FROM erseco/alpine-php7-webserver:latest
USER root
# Install composer from the official image
RUN apk add --no-cache composer
USER nobody
# Run composer install to install the dependencies
RUN composer install --optimize-autoloader --no-interaction --no-progress

Building with composer

If you are building an image with source code in it and dependencies managed by composer then the definition can be improved. The dependencies should be retrieved by the composer but the composer itself (/usr/bin/composer) is not necessary to be included in the image.

FROM composer AS composer

# copying the source directory and install the dependencies with composer
COPY <your_directory>/ /app

# run composer install to install the dependencies
RUN composer install \
  --optimize-autoloader \
  --no-interaction \
  --no-progress

# continue stage build with the desired image and copy the source including the
# dependencies downloaded by composer
FROM trafex/alpine-nginx-php7
COPY --chown=nginx --from=composer /app /var/www/html