<?php
namespace Aws\Retry;
use Aws\AbstractConfigurationProvider;
use Aws\CacheInterface;
use Aws\ConfigurationProviderInterface;
use Aws\Retry\Exception\ConfigurationException;
use GuzzleHttp\Promise;
use GuzzleHttp\Promise\PromiseInterface;
/**
* A configuration provider is a function that returns a promise that is
* fulfilled with a {@see \Aws\Retry\ConfigurationInterface}
* or rejected with an {@see \Aws\Retry\Exception\ConfigurationException}.
*
* <code>
* use Aws\Sts\RegionalEndpoints\ConfigurationProvider;
* $provider = ConfigurationProvider::defaultProvider();
* // Returns a ConfigurationInterface or throws.
* $config = $provider()->wait();
* </code>
*
* Configuration providers can be composed to create configuration using
* conditional logic that can create different configurations in different
* environments. You can compose multiple providers into a single provider using
* {@see \Aws\Retry\ConfigurationProvider::chain}. This function
* accepts providers as variadic arguments and returns a new function that will
* invoke each provider until a successful configuration is returned.
*
* <code>
* // First try an INI file at this location.
* $a = ConfigurationProvider::ini(null, '/path/to/file.ini');
* // Then try an INI file at this location.
* $b = ConfigurationProvider::ini(null, '/path/to/other-file.ini');
* // Then try loading from environment variables.
* $c = ConfigurationProvider::env();
* // Combine the three providers together.
* $composed = ConfigurationProvider::chain($a, $b, $c);
* // Returns a promise that is fulfilled with a configuration or throws.
* $promise = $composed();
* // Wait on the configuration to resolve.
* $config = $promise->wait();
* </code>
*/
class ConfigurationProvider extends AbstractConfigurationProvider
implements ConfigurationProviderInterface
{
const DEFAULT_MAX_ATTEMPTS = 3;
const DEFAULT_MODE = 'legacy';
const ENV_MAX_ATTEMPTS = 'AWS_MAX_ATTEMPTS';
const ENV_MODE = 'AWS_RETRY_MODE';
const ENV_PROFILE = 'AWS_PROFILE';
const INI_MAX_ATTEMPTS = 'max_attempts';
const INI_MODE = 'retry_mode';
public static $cacheKey = 'aws_retries_config';
protected static $interfaceClass = ConfigurationInterface::class;
protected static $exceptionClass = ConfigurationException::class;
/**
* Create a default config provider that first checks for environment
* variables, then checks for a specified profile in the environment-defined
* config file location (env variable is 'AWS_CONFIG_FILE', file location
* defaults to ~/.aws/config), then checks for the "default" profile in the
* environment-defined config file location, and failing those uses a default
* fallback set of configuration options.
*
* This provider is automatically wrapped in a memoize function that caches
* previously provided config options.
*
* @param array $config
*
* @return callable
*/
public static function defaultProvider(array $config = [])
{
$configProviders = [self::env()];
if (
!isset($config['use_aws_shared_config_files'])
|| $config['use_aws_shared_config_files'] != false
) {
$configProviders[] = self::ini();
}
$configProviders[] = self::fallback();
$memo = self::memoize(
call_user_func_array('self::chain', $configProviders)
);
if (isset($config['retries'])
&& $config['retries'] instanceof CacheInterface
) {
return self::cache($memo, $config['retries'], self::$cacheKey);
}
return $memo;
}
/**
* Provider that creates config from environment variables.
*
* @return callable
*/
public static function env()
{
return function () {
// Use config from environment variables, if available
$mode = getenv(self::ENV_MODE);
$maxAttempts = getenv(self::ENV_MAX_ATTEMPTS)
? getenv(self::ENV_MAX_ATTEMPTS)
: self::DEFAULT_MAX_ATTEMPTS;
if (!empty($mode)) {
return Promise\promise_for(
new Configuration($mode, $maxAttempts)
);
}
return self::reject('Could not find environment variable config'
. ' in ' . self::ENV_MODE);
};
}
/**
* Fallback config options when other sources are not set.
*
* @return callable
*/
public static function fallback()
{
return function () {
return Promise\promise_for(
new Configuration(self::DEFAULT_MODE, self::DEFAULT_MAX_ATTEMPTS)
);
};
}
/**
* Config provider that creates config using a config file whose location
* is specified by an environment variable 'AWS_CONFIG_FILE', defaulting to
* ~/.aws/config if not specified
*
* @param string|null $profile Profile to use. If not specified will use
* the "default" profile.
* @param string|null $filename If provided, uses a custom filename rather
* than looking in the default directory.
*
* @return callable
*/
public static function ini(
$profile = null,
$filename = null
) {
$filename = $filename ?: (self::getDefaultConfigFilename());
$profile = $profile ?: (getenv(self::ENV_PROFILE) ?: 'default');
return function () use ($profile, $filename) {
if (!@is_readable($filename)) {
return self::reject("Cannot read configuration from $filename");
}
$data = \Aws\parse_ini_file($filename, true);
if ($data === false) {
return self::reject("Invalid config file: $filename");
}
if (!isset($data[$profile])) {
return self::reject("'$profile' not found in config file");
}
if (!isset($data[$profile][self::INI_MODE])) {
return self::reject("Required retry config values
not present in INI profile '{$profile}' ({$filename})");
}
$maxAttempts = isset($data[$profile][self::INI_MAX_ATTEMPTS])
? $data[$profile][self::INI_MAX_ATTEMPTS]
: self::DEFAULT_MAX_ATTEMPTS;
return Promise\promise_for(
new Configuration(
$data[$profile][self::INI_MODE],
$maxAttempts
)
);
};
}
/**
* Unwraps a configuration object in whatever valid form it is in,
* always returning a ConfigurationInterface object.
*
* @param mixed $config
* @return ConfigurationInterface
* @throws \InvalidArgumentException
*/
public static function unwrap($config)
{
if (is_callable($config)) {
$config = $config();
}
if ($config instanceof PromiseInterface) {
$config = $config->wait();
}
if ($config instanceof ConfigurationInterface) {
return $config;
}
// An integer value for this config indicates the legacy 'retries'
// config option, which is incremented to translate to max attempts
if (is_int($config)) {
return new Configuration('legacy', $config + 1);
}
if (is_array($config) && isset($config['mode'])) {
$maxAttempts = isset($config['max_attempts'])
? $config['max_attempts']
: self::DEFAULT_MAX_ATTEMPTS;
return new Configuration($config['mode'], $maxAttempts);
}
throw new \InvalidArgumentException('Not a valid retry configuration'
. ' argument.');
}
}