/php-config

PSR-16 Simple Cache like configuration interfaces; ini-file based and cached

Primary LanguagePHPMIT LicenseMIT

Config

Simple and sectioned configuration interfaces

ConfigInterface
is basically PSR-16 Simple Cache without time-to-live.
There's a key and a value.

That principle isn't optimal for general use, unless you like real long and complex key names.

SectionedConfigInterface
Splits the item key into 'section' plus 'key', facilitating a more organized structure.

The immediate benefit is that you can namespace all items that belong to a particular library.

The section-key pattern can be implemented and utilized in two manners:

  • concatenation: the configuration setters and getters simply concatenate section and key
  • listing: the section is a list of keys, you can access the whole section as well as a particular key

SectionedConfigInterface also allows for short-term keeping items in memory, via methods remember() and forget().

Implementations

Environment variable based

EnvConfig
is a simple abstraction of server environment variables.

EnvSectionedConfig
a sectioned implementation, using concatenation.

Ini-files as source, cache as store

The ini-file based classes parse ini-files, and save to cache stores.

They read recursively from their ini-file paths. That allows one to clone and use ini-files from multiple version control repositories.

Ini-files are so old-school...

Aye, but the ini format is less error-prone than JSON, YAML, what-not.
The syntax is so simple it's hard to make mistakes. And operations people are used to ini-files.

Cache layer

is SimpleComplex Cache PersistentFileCache.
Cache store names are prefixed with 'config.'
Beware of conflict; do not prefix other cache stores that way.

Types of ini-based configuration

IniConfig
is not sectioned. Simple but probably not that useful.
$value = $config->get('key')

IniSectionedConfig
is a powerful general usage implementation.
$value = $config->get('section', 'key')

Reads ini-files from a base path and an override path.
Keep development/production invariant variables (ini-files) in the base path.
Let operations keep production variables in the override path.

Using the list-principle - and fully supporting remember() and forget() - IniSectionedConfig is optimal for accessing many/all keys of a section within a limited procedure.

IniSectionedFlatConfig
a sectioned implementation, using concatenation.

Optimal for types of configuration one expects to access keys of diverse sections in an unpredictable manner, but still want the organisational benefit of sections; many but exact cache reads.
SimpleComplex Locale uses this config class for localized texts.

Abstraction

The Config class is an abstraction of sectioned configuration.

In this package it extends IniSectionedConfig.
In an extending package it could be some other sectioned config implementation.

CLI interface

CliConfig delivers CLI commands for setting, getting and deleting config items.
And commands for refreshing and exporting full configuration stores.

It exposes IniSectionedConfig instances, via the Config class.
The other config classes are not accessible via CLI.

Global config

Config defaults to deliver an instance named 'global'.

A typical system could probably benefit from a single config instance for the bulk of items.
Since the whole thing runtime is cache based, there's no performance reason for using multiple instances.

Dependency injection container ID: config

Recommendation: access (and thus instantiate) the global config via DI container ID 'config'.
See SimpleComplex Utils Dependency.

Example

// Bootstrap.
Dependency::genericSetMultiple([
    'cache-broker' => function () {
        return new \SimpleComplex\Cache\CacheBroker();
    },
    'config' => function() {
        return new \SimpleComplex\Config\Config('global');
    },
]);
// ...
// Use.
/** @var \Psr\Container\ContainerInterface $container */
$container = Dependency::container();
/**
 * Create or re-initialize the 'global' config store;
 * based on ini-files placed in base and override paths,
 * cached by a PSR-16 Simple Cache cache store.
 *
 * @var \SimpleComplex\Config\IniSectionedConfig $config
 */
$config = $container->get('config');
/** @var mixed $whatever */
$whatever = $config->get('some-section', 'some-key', 'the default value');

CLI commands

# List all config commands and their help.
php cli.php config -h
# One command's help.
php cli.php config-xxx -h

# List existing config stores.
php cli.php config-list-stores

# Display/get value of a config item.
php cli.php config-get store section key

# Set a config item.
php cli.php config-set store section key value

# Delete a config item.
php cli.php config-delete store section key

# Refresh a config store from .ini file sources.
# The fresh store gets applied atomically, when fully built.
php cli.php config-refresh store

# Export a config store as JSON to a file.
php cli.php config-export store target-path-and-file

Installation

Create a 'conf' directory alongside the document root dir.

Like:
/var/www/my-host/http
/var/www/my-host/conf

Create 'base' and 'override' paths within the 'conf', like:
conf/ini/base
conf/ini/override

For the 'global' config store, place or symlink or git clone your system's
.ini configuration files under the 'base' and 'override' paths
using file extension global.ini (= [store name].ini).

Like:
conf/ini/base/some-ding.global.ini
conf/ini/override/some-ding.prod.global.ini

If that directory structure isn't suitable, do either:

  • supply Config constructor with a 'paths' argument
  • extend Config and override it's class constant PATH_DEFAULTS

Requirements

Suggestions