PHP配置中心与动态配置管理

PHP配置中心与动态配置管理

配置管理是应用运维的重要环节。配置中心可以让配置动态变更，不需要重启应用。今天说说PHP中的配置管理方案。

传统的配置文件方式简单直接，但修改配置需要重新部署。

```php
// 文件配置
class FileConfig
{
private array $configs = [];
private string $configDir;
private array $loaded = [];

public function __construct(string $configDir = __DIR__ . '/config')
{
$this->configDir = rtrim($configDir, '/');
}

public function load(): void
{
$files = glob($this->configDir . '/*.php');
foreach ($files as $file) {
$key = basename($file, '.php');
$this->configs[$key] = require $file;
$this->loaded[] = $key;
}
}

public function get(string $key, mixed $default = null): mixed
{
$keys = explode('.', $key);
$value = $this->configs;

foreach ($keys as $segment) {
if (!is_array($value) || !array_key_exists($segment, $value)) {
return $default;
}
$value = $value[$segment];
}

return $value;
}

public function set(string $key, mixed $value): void
{
$keys = explode('.', $key);
$config = &$this->configs;

foreach ($keys as $segment) {
if (!isset($config[$segment])) {
$config[$segment] = [];
}
$config = &$config[$segment];
}

$config = $value;
}

public function all(): array
{
return $this->configs;
}

public function reload(): void
{
$this->configs = [];
$this->load();
}
}
?>

// config/app.php
return [
'name' => 'MyApp',
'debug' => false,
'env' => 'production',
'timezone' => 'Asia/Shanghai',
];
?>

// config/database.php
return [
'default' => 'mysql',
'connections' => [
'mysql' => [
'host' => 'localhost',
'port' => 3306,
'database' => 'test',
'username' => 'root',
'password' => '',
'charset' => 'utf8mb4',
],
'redis' => [
'host' => 'localhost',
'port' => 6379,
'database' => 0,
],
],
];
?>

$config = new FileConfig();
$config->load();
echo "应用名称: " . $config->get('app.name') . "\n";
echo "数据库主机: " . $config->get('database.connections.mysql.host') . "\n";
?>
```

基于Redis的动态配置中心：

```php
class RedisConfigCenter
{
private Redis $redis;
private string $prefix = 'config:';
private array $localCache = [];
private int $cacheTtl = 60;

public function __construct(Redis $redis)
{
$this->redis = $redis;
}

public function get(string $key, mixed $default = null): mixed
{
$cacheKey = "{$this->prefix}{$key}";

// 从本地缓存获取
if (isset($this->localCache[$cacheKey])) {
$cached = $this->localCache[$cacheKey];
if ($cached['expires'] > time()) {
return $cached['value'];
}
}

// 从Redis获取
$value = $this->redis->get($cacheKey);
if ($value === false) {
return $default;
}

$decoded = json_decode($value, true);
$this->localCache[$cacheKey] = [
'value' => $decoded,
'expires' => time() + $this->cacheTtl,
];

return $decoded;
}

public function set(string $key, mixed $value): void
{
$cacheKey = "{$this->prefix}{$key}";
$this->redis->set($cacheKey, json_encode($value));
unset($this->localCache[$cacheKey]);

// 发布配置变更通知
$this->redis->publish('config_changes', json_encode([
'key' => $key,
'time' => time(),
]));
}

public function delete(string $key): void
{
$cacheKey = "{$this->prefix}{$key}";
$this->redis->del($cacheKey);
unset($this->localCache[$cacheKey]);
}

public function getMultiple(array $keys): array
{
$results = [];
foreach ($keys as $key) {
$results[$key] = $this->get($key);
}
return $results;
}

public function setMultiple(array $configs): void
{
foreach ($configs as $key => $value) {
$this->set($key, $value);
}
}

public function getAllWithPrefix(string $prefix = ''): array
{
$pattern = "{$this->prefix}{$prefix}*";
$keys = $this->redis->keys($pattern);
$result = [];

foreach ($keys as $key) {
$configKey = str_replace($this->prefix, '', $key);
$result[$configKey] = json_decode($this->redis->get($key), true);
}

return $result;
}

public function watchChanges(callable $callback): void
{
$this->redis->subscribe(['config_changes'], function ($redis, $channel, $message) use ($callback) {
$data = json_decode($message, true);
$callback($data['key'], $data['time']);
});
}
}

$redis = new Redis();
$redis->connect('127.0.0.1', 6379);

$configCenter = new RedisConfigCenter($redis);

$configCenter->set('app.debug', true);
$configCenter->set('app.name', 'MyApp');
$configCenter->set('database.host', 'localhost');
$configCenter->set('database.port', 3306);
$configCenter->set('cache.ttl', 3600);
$configCenter->set('features.new_ui', false);

echo "调试模式: " . ($configCenter->get('app.debug') ? '开启' : '关闭') . "\n";
echo "数据库主机: " . $configCenter->get('database.host') . "\n";
echo "缓存TTL: " . $configCenter->get('cache.ttl') . "\n";
echo "默认值: " . $configCenter->get('nonexistent', 'default') . "\n";
?>
```

环境配置的自动切换：

```php
class EnvironmentConfig
{
private array $configs = [];
private string $env;

public function __construct()
{
$this->env = $this->detectEnvironment();
$this->loadConfigs();
}

private function detectEnvironment(): string
{
$env = getenv('APP_ENV');
if ($env) return $env;

if (file_exists('.env.local')) return 'local';
if (file_exists('.env.dev'])) return 'development';
if (file_exists('.env.staging')) return 'staging';

return 'production';
}

private function loadConfigs(): void
{
$envFile = ".env.{$this->env}";
$baseFile = '.env';

$files = [$baseFile, $envFile];
foreach ($files as $file) {
if (file_exists($file)) {
$this->parseEnvFile($file);
}
}
}

private function parseEnvFile(string $path): void
{
$lines = file($path, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

foreach ($lines as $line) {
$line = trim($line);
if ($line === '' || str_starts_with($line, '#')) continue;

if (str_contains($line, '=')) {
[$key, $value] = explode('=', $line, 2);
$key = trim($key);
$value = trim($value);

// 处理引号
if (str_starts_with($value, '"') && str_ends_with($value, '"')) {
$value = substr($value, 1, -1);
}

// 类型转换
$value = match (strtolower($value)) {
'true' => true,
'false' => false,
'null' => null,
default => $value,
};

$this->configs[$key] = $value;
putenv("{$key}=" . (is_bool($value) ? ($value ? 'true' : 'false') : (string)$value));
}
}
}

public function get(string $key, mixed $default = null): mixed
{
return $this->configs[$key] ?? getenv($key) ?: $default;
}

public function getEnvironment(): string
{
return $this->env;
}

public function isLocal(): bool
{
return $this->env === 'local';
}

public function isProduction(): bool
{
return $this->env === 'production';
}

public function isDevelopment(): bool
{
return $this->env === 'development';
}

public function all(): array
{
return $this->configs;
}
}

$config = new EnvironmentConfig();
echo "当前环境: " . $config->getEnvironment() . "\n";
echo "是否生产环境: " . ($config->isProduction() ? '是' : '否') . "\n";
?>
```

配置是应用的基石。好的配置管理方案可以让运维更轻松，开发更高效。文件配置简单明了，适合中小项目。配置中心灵活强大，适合分布式系统。环境配置通过.env文件自动切换，是开发环境的标配。