PHP - Source-to-Image (<strong>s2i</strong>) | Using Images

Overview
Versions
Images
Configuration
- Apache Configuration
Accessing Logs
Hot Deploying

Overview

OpenShift Enterprise provides s2i enabled PHP images for building and running PHP applications. The PHP s2i builder image assembles your application source with any required dependencies to create a new image containing your PHP application. This resulting image can be run either by OpenShift Enterprise or by Docker.

Versions

Currently, OpenShift Enterprise provides version 5.5 and 5.6 of PHP.

Images

This image comes in two flavors, depending on your needs:

RHEL 7
CentOS 7

RHEL 7 Based Image

The RHEL 7 image is available through Red Hat’s subscription registry using:

$ docker pull registry.access.redhat.com/openshift3/php-55-rhel7

CentOS 7 Based Image

This image is available on DockerHub. To download it:

$ docker pull openshift/php-55-centos7

To use these images, you can either access them directly from these image registries, or push them into your OpenShift Enterprise Docker registry. Additionally, you can create an image stream that points to the image, either in your Docker registry or at the external location. Your OpenShift Enterprise resources can then reference the image stream.

You can find example image stream definitions for all the provided OpenShift Enterprise images.

Configuration

The PHP image supports a number of environment variables which can be set to control the configuration and behavior of the PHP runtime.

To set these environment variables, you can place them into a .sti/environment file inside your source code repository, or define them in the environment section of the build configuration’s sourceStrategy definition.

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

Table 1. PHP Environment Variables
Variable name	Description	Default
`ERROR_REPORTING`	Informs PHP of the errors, warnings, and notices for which you would like it to take action.	E_ALL & ~E_NOTICE
`DISPLAY_ERRORS`	Controls if and where PHP outputs errors, notices, and warnings.	ON
`DISPLAY_STARTUP_ERRORS`	Causes any display errors that occur during PHP’s startup sequence to be handled separately from display errors.	OFF
`TRACK_ERRORS`	Stores the last error/warning message in `$php_errormsg` (boolean).	OFF
`HTML_ERRORS`	Links errors to documentation that is related to the error.	ON
`INCLUDE_PATH`	Path for PHP source files.	*.:/opt/openshift/src:/opt/rh/php55/root/usr/share/pear*
`SESSION_PATH`	Location for session data files.	*/tmp/sessions*

The following environment variable sets its equivalent property value in the opcache.ini file:

Table 2. Additional PHP settings
Variable name	Description	Default
`OPCACHE_MEMORY_CONSUMPTION`	The OPcache shared memory storage size.	16M
`OPCACHE_REVALIDATE_FREQ`	How often to check script time stamps for updates, in seconds. 0 results in OPcache checking for updates on every request.	2

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

Table 3. Additional PHP settings
Variable name	Description
`PHPRC`	Sets the path to the *php.ini* file.
`PHP_INI_SCAN_DIR`	Path to scan for additional *.ini* configuration files

Apache Configuration

If the DocumentRoot of the application is nested in the source directory /opt/openshift/src, you can provide your own .htaccess file to override the default Apache behavior and specify how application requests should be handled. The .htaccess file must be located at the root of the application source.

Accessing Logs

Access logs are streamed to standard out and as such they can be viewed using the oc logs command. Error logs are stored in the /tmp/error_log file, which can be viewed using the oc rsh command to access the container.

Hot Deploying

Hot deployment allows you to quickly make and deploy changes to your application without having to generate a new s2i build. In order to immediately pick up changes made in your application source code, you must run your built image with the OPCACHE_REVALIDATE_FREQ=0 environment variable.

For example, see the oc new-app command. You can use the oc env command to update environment variables of existing objects.

You should only use this option while developing or debugging; it is not recommended to turn this on in your production environment.

To change your source code in a running pod, use the oc rsh command to enter the container:

$ oc rsh <pod_id>

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