centos/php-56-centos7 repository overview

⁠PHP 5.6 Docker image

This container image includes PHP 5.6 as a S2I⁠ base image for your PHP 5.6 applications. Users can choose between RHEL and CentOS based builder images. The RHEL image is available in the Red Hat Container Catalog⁠ as registry.access.redhat.com/rhscl/php-56-rhel7. The CentOS image is then available on Docker Hub⁠ as centos/php-56-centos7. The resulting image can be run using Docker⁠.

⁠Description

PHP 5.6 available as container is a base platform for building and running various PHP 5.6 applications and frameworks. PHP is an HTML-embedded scripting language. PHP attempts to make it easy for developers to write dynamically generated web pages. PHP also offers built-in database integration for several commercial and non-commercial database management systems, so writing a database-enabled webpage with PHP is fairly simple. The most common use of PHP coding is probably as a replacement for CGI scripts.

⁠Usage

To build a simple php-test-app⁠ application using standalone S2I⁠ and then run the resulting image with Docker⁠ execute:

• For RHEL based image

  $ s2i build https://github.com/sclorg/s2i-php-container.git --context-dir=5.6/test/test-app rhscl/php-56-rhel7 php-test-app
  $ docker run -p 8080:8080 php-test-app
  

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• For CentOS based image

  $ s2i build https://github.com/sclorg/s2i-php-container.git --context-dir=5.6/test/test-app centos/php-56-centos7 php-test-app
  $ docker run -p 8080:8080 php-test-app
  

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Accessing the application:

$ curl 127.0.0.1:8080

⁠Environment variables

To set these environment variables, you can place them as a key value pair into a .sti/environment file inside your source code repository.

The following environment variables set their equivalent property value in the php.ini file:

• ERROR_REPORTING
  • Informs PHP of which errors, warnings and notices you would like it to take action for
  • Default: E_ALL & ~E_NOTICE
• DISPLAY_ERRORS
  • Controls whether or not and where PHP will output errors, notices and warnings
  • Default: ON
• DISPLAY_STARTUP_ERRORS
  • Cause display errors which occur during PHP's startup sequence to be handled separately from display errors
  • Default: OFF
• TRACK_ERRORS
  • Store the last error/warning message in $php_errormsg (boolean)
  • Default: OFF
• HTML_ERRORS
  • Link errors to documentation related to the error
  • Default: ON
• INCLUDE_PATH
  • Path for PHP source files
  • Default: .:/opt/app-root/src:/opt/rh/rh-php56/root/usr/share/pear
• SESSION_NAME
  • Name of the session
  • Default: PHPSESSID
• SESSION_HANDLER
  • Method for saving sessions
  • Default: files
• SESSION_PATH
  • Location for session data files
  • Default: /tmp/sessions
• SESSION_COOKIE_DOMAIN
  • The domain for which the cookie is valid.
  • Default:
• SESSION_COOKIE_HTTPONLY
  • Whether or not to add the httpOnly flag to the cookie
  • Default: 0
• SESSION_COOKIE_SECURE
  • Specifies whether cookies should only be sent over secure connections.
  • Default: Off
• SHORT_OPEN_TAG
  • Determines whether or not PHP will recognize code between tags
  • Default: OFF
• DOCUMENTROOT
  • Path that defines the DocumentRoot for your application (ie. /public)
  • Default: /

The following environment variables set their equivalent property value in the opcache.ini file:

• OPCACHE_MEMORY_CONSUMPTION
  • The OPcache shared memory storage size in megabytes
  • Default: 128
• OPCACHE_REVALIDATE_FREQ
  • How often to check script timestamps for updates, in seconds. 0 will result in OPcache checking for updates on every request.
  • Default: 2

You can also override the entire directory used to load the PHP configuration by setting:

• PHPRC
  • Sets the path to the php.ini file
• PHP_INI_SCAN_DIR
  • Path to scan for additional ini configuration files

You can override the Apache MPM prefork⁠ settings to increase the performance for of the PHP application. In case you set the Cgroup limits in Docker, the image will attempt to automatically set the optimal values. You can override this at any time by specifying the values yourself:

• HTTPD_START_SERVERS

  • The StartServers⁠ directive sets the number of child server processes created on startup.
  • Default: 8

• HTTPD_MAX_REQUEST_WORKERS

  • The MaxRequestWorkers⁠ directive sets the limit on the number of simultaneous requests that will be served.
  • MaxRequestWorkers was called MaxClients before version httpd 2.3.13.
  • Default: 256 (this is automatically tuned by setting Cgroup limits for the container using this formula: TOTAL_MEMORY / 15MB. The 15MB is average size of a single httpd process.

  You can use a custom composer repository mirror URL to download packages instead of the default 'packagist.org':

  • COMPOSER_MIRROR
    • Adds a custom composer repository mirror URL to composer configuration. Note: This only affects packages listed in composer.json.
  • COMPOSER_INSTALLER
    • Overrides the default URL for downloading Composer of https://getcomposer.org/installer⁠. Useful in disconnected environments.
  • COMPOSER_ARGS
    • Adds extra arguments to the composer install command line (for example --no-dev).

⁠Source repository layout

You do not need to change anything in your existing PHP project's repository. However, if these files exist they will affect the behavior of the build process:

• composer.json

  List of dependencies to be installed with composer. The format is documented here⁠.

• .htaccess

  In case the DocumentRoot of the application is nested within the source directory /opt/app-root/src, users can provide their own Apache .htaccess file. This allows the overriding of Apache's behavior and specifies how application requests should be handled. The .htaccess file needs to be located at the root of the application source.

⁠Hot deploy

In order to immediately pick up changes made in your application source code, you need to run your built image with the OPCACHE_REVALIDATE_FREQ=0 environment variable passed to the Docker⁠ -e run flag:

$ docker run -e OPCACHE_REVALIDATE_FREQ=0 -p 8080:8080 php-app

To change your source code in running container, use Docker's exec⁠ command:

docker exec -it <CONTAINER_ID> /bin/bash

After you Docker exec⁠ into the running container, your current directory is set to /opt/app-root/src, where the source code is located.

⁠Extending image

Not only content, but also startup scripts and configuration of the image can be extended using source-to-image⁠.

The structure of the application can look like this:

⁠See also

Dockerfile and other sources are available on https://github.com/sclorg/s2i-php-container⁠. In that repository you also can find another versions of PHP environment Dockerfiles. Dockerfile for CentOS is called Dockerfile, Dockerfile for RHEL is called Dockerfile.rhel7.

⁠Security Implications

-p 8080:8080

 Opens  container  port  8080  and  maps it to the same port on the Host.