platformsh/config-reader

Small helper to access Platform.sh environment variables

2.0.1 2019-03-05 19:00 UTC

README

This library provides a streamlined and easy to use way to interact with a Platform.sh environment. It offers utility methods to access routes and relationships more cleanly than reading the raw environment variables yourself.

This library requires PHP 7.1 or later.

Install

composer install platformsh/config-reader

Usage Example

Example:

use Platformsh\ConfigReader\Config;

$config = new Config();

if (!$config->isValidPlatform()) {
    die("Not in a Platform.sh Environment.");
}

$credentials = $config->credentials('database');

$conn = new \PDO($config->formattedCredentials('database', 'pdo_mysql'), $credentials['username'], $credentials['password'], [
    // Always use Exception error mode with PDO, as it's more reliable.
    \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
    // So we don't have to mess around with cursors and unbuffered queries by default.
    \PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => TRUE,
    // Make sure MySQL returns all matched rows on update queries including
    // rows that actually didn't have to be updated because the values didn't
    // change. This matches common behavior among other database systems.
    \PDO::MYSQL_ATTR_FOUND_ROWS => TRUE,
]);

// Do stuff with the $conn here.

API Reference

Create a config object

use Platformsh\ConfigReader\Config;

$config = new Config();

config is now a Platformsh\ConfigReder\Config object that provides access to the Platform.sh environment.

The isValidPlatform() method returns true if the code is running in a context that has Platform.sh environment variables defined. If it returns false then most other functions will throw exceptions if used.

Inspect the environment

The following methods return true or false to help determine in what context the code is running:

$config->inBuild();

$config->inRuntime();

$config->onEnterprise();

$config->onProduction();

Read environment variables

The following magic properties return the corresponding environment variable value. See the Platform.sh documentation for a description of each.

The following are available both in Build and at Runtime:

$config->applicationName;

$config->appDir;

$config->project;

$config->treeId;

$config->projectEntropy;

The following are available only if inRuntime() returned true:

$config->branch;

$config->documentRoot;

$config->smtpHost;

$config->environment;

$config->socket;

$config->port;

Reading service credentials

Platform.sh services are defined in a services.yaml file, and exposed to an application by listing a relationship to that service in the application's .platform.app.yaml file. User, password, host, etc. information is then exposed to the running application in the PLATFORM_RELATIONSHIPS environment variable, which is a base64-encoded JSON string. The following method allows easier access to credential information than decoding the environment variable yourself.

$creds = $config->credentials('database');

The return value of credentials() is an associative array matching the relationship JSON object, which includes the appropriate user, password, host, database name, and other pertinent information. See the Service documentation for your service for the exact structure and meaning of each property. In most cases that information can be passed directly to whatever other client library is being used to connect to the service.

Formatting service credentials

In some cases the library being used to connect to a service wants its credentials formatted in a specific way; it could be a DSN string of some sort or it needs certain values concatenated to the database name, etc. For those cases you can use "Credential Formatters". A Credential Formatter is any callable (function, anonymous function, object method, etc.) that takes a credentials array and returns any type, since the library may want different types.

Credential Formatters can be registered on the configuration object, and a few are included out of the box. That allows 3rd party libraries to ship their own formatters that can be easily integrated into the Config object to allow easier use.

function formatMyService(array $credentials) string 
{
	return "some string based on $credentials";
}

// Call this in setup.
$config->registerFormatter("my_service", 'formatMyService');


// Then call this method to get the formatted version

$formatted = $config->FormattedCredentials("database", "my_service");

The first parameter is the name of a relationship defined in .platform.app.yaml. The second is a formatter that was previously registered with registerFormatter(). If either the service or formatter is missing an exception will be thrown. The type of formatted will depend on the formatter function and can be safely passed directly to the client library.

Two formatters are included out of the box:

  • pdo_mysql returns a DSN appropriate for using with PDO to connect to MySQL or MariaDB. Note that PDO will still need the username and password from the credentials array passed as separate parameters.
  • pdo_pgsql returns a DSN appropriate for using with PDO to connect to PostgreSQL. Note that PDO will still need the username and password from the credentials array passed as separate parameters.

Reading Platform.sh variables

Platform.sh allows you to define arbitrary variables that may be available at build time, runtime, or both. They are stored in the PLATFORM_VARIABLES environment variable, which is a base64-encoded JSON string.

The following two methods allow access to those values from your code without having to bother decoding the values yourself:

$config->variables();

This method returns an associative array of all variables defined. Usually this method is not necessary and $config->variable() is preferred.

$config->variable("foo", "default");

This method looks for the "foo" variable. If found, it is returned. If not, the optional second parameter is returned as a default.

Reading Routes

Routes on Platform.sh define how a project will handle incoming requests; that primarily means what application container will serve the request, but it also includes cache configuration, TLS settings, etc. Routes may also have an optional ID, which is the preferred way to access them.

$config->route("main");

The route() method takes a single string for the route ID ("main" in this case) and returns the corresponding route array. If the route is not found it will throw an exception.

To access all routes, or to search for a route that has no ID, the routes() method returns an associative array of routes keyed by their URL. That mirrors the structure of the PLATFORM_ROUTES environment variable.

If called in the build phase an exception is thrown.