PHP配置即代码与基础设施管理

PHP配置即代码与基础设施管理

配置即代码（Infrastructure as Code）的理念将基础设施配置纳入版本控制。PHP可以通过配置文件和代码来自动化管理服务器和基础设施。今天说说PHP中配置即代码的实现。

基础设施配置文件描述所需的基础设施状态。

```php
class InfrastructureDefinition
{
public function __construct(
public string $name,
public string $type,
public array $spec = [],
public array $metadata = []
) {}
}

class InfrastructureManager
{
private array $definitions = [];

public function addResource(InfrastructureDefinition $definition): void
{
$this->definitions[] = $definition;
}

public function validate(): array
{
$errors = [];

foreach ($this->definitions as $def) {
if (empty($def->name)) {
$errors[] = '资源名称不能为空';
}

if ($def->type === 'database' && empty($def->spec['engine'])) {
$errors[] = "数据库 {$def->name} 必须指定引擎类型";
}

if ($def->type === 'service' && empty($def->spec['port'])) {
$errors[] = "服务 {$def->name} 必须指定端口";
}
}

return $errors;
}

public function generateCloudFormation(): array
{
$resources = [];

foreach ($this->definitions as $def) {
$resources[$def->name] = $this->generateResource($def);
}

return ['Resources' => $resources];
}

private function generateResource(InfrastructureDefinition $def): array
{
return match ($def->type) {
'database' => [
'Type' => 'AWS::RDS::DBInstance',
'Properties' => [
'Engine' => $def->spec['engine'],
'DBInstanceClass' => $def->spec['instanceClass'] ?? 'db.t3.micro',
'AllocatedStorage' => $def->spec['storage'] ?? 20,
],
],
'service' => [
'Type' => 'AWS::ECS::Service',
'Properties' => [
'TaskDefinition' => $def->name,
'DesiredCount' => $def->spec['desiredCount'] ?? 1,
],
],
'bucket' => [
'Type' => 'AWS::S3::Bucket',
'Properties' => [
'BucketName' => $def->name,
],
],
default => [],
};
}
}
?>

基础设施的部署和状态检查：

```php
class DeploymentManager
{
private array $resources = [];
private string $stateFile;

public function __construct(string $stateFile = '/var/state/infrastructure.json')
{
$this->stateFile = $stateFile;
$this->loadState();
}

public function deploy(InfrastructureManager $manager): array
{
$errors = $manager->validate();
if (!empty($errors)) {
return ['success' => false, 'errors' => $errors];
}

$template = $manager->generateCloudFormation();
$results = [];

foreach ($template['Resources'] as $name => $resource) {
try {
$this->resources[$name] = [
'status' => 'deployed',
'type' => $resource['Type'],
'deployed_at' => date('c'),
];
$results[$name] = ['success' => true];
} catch (\Exception $e) {
$results[$name] = ['success' => false, 'error' => $e->getMessage()];
}
}

$this->saveState();
return ['success' => true, 'results' => $results];
}

public function getState(string $resource = null): array
{
if ($resource) {
return $this->resources[$resource] ?? [];
}
return $this->resources;
}

public function diff(InfrastructureManager $manager): array
{
$template = $manager->generateCloudFormation();
$changes = [];

foreach ($template['Resources'] as $name => $resource) {
$currentState = $this->resources[$name] ?? null;
if ($currentState === null) {
$changes[] = ['action' => 'create', 'resource' => $name];
}
}

foreach ($this->resources as $name => $state) {
if (!isset($template['Resources'][$name])) {
$changes[] = ['action' => 'delete', 'resource' => $name];
}
}

return $changes;
}

private function loadState(): void
{
if (file_exists($this->stateFile)) {
$this->resources = json_decode(file_get_contents($this->stateFile), true) ?: [];
}
}

private function saveState(): void
{
$dir = dirname($this->stateFile);
if (!is_dir($dir)) mkdir($dir, 0755, true);
file_put_contents($this->stateFile, json_encode($this->resources, JSON_PRETTY_PRINT));
}
}

$infra = new InfrastructureManager();
$infra->addResource(new InfrastructureDefinition('app-database', 'database', [
'engine' => 'mysql',
'instanceClass' => 'db.t3.small',
'storage' => 50,
]));
$infra->addResource(new InfrastructureDefinition('app-cache', 'service', [
'port' => 6379,
'desiredCount' => 2,
]));
$infra->addResource(new InfrastructureDefinition('app-assets', 'bucket', []));

$errors = $infra->validate();
if (empty($errors)) {
echo "配置验证通过\n";
$deployer = new DeploymentManager();
$result = $deployer->deploy($infra);
echo json_encode($result, JSON_PRETTY_PRINT) . "\n";
} else {
echo "配置错误: " . implode(', ', $errors) . "\n";
}
?>

配置即代码让基础设施管理变得可重复、可审计、可版本化。通过代码定义基础设施，可以在不同环境中创建一致的部署。配置变更通过代码审查来管理，降低人为操作的风险。PHP虽然不是主流的基础设施管理工具，但实现简单的配置管理功能很方便。