[PHP-Casbin](https://github.com/php-casbin/php-casbin) 是一个强大的、高效的开源访问控制框架，它支持基于各种访问控制模型的权限管理。
这里使用官方提供的数据库适配器扩展：[Database adapter](https://github.com/php-casbin/database-adapter).
### 安装
通过`composer`安装：
```
composer require casbin/casbin
composer require casbin/database-adapter
```
### 使用 RBAC Model
model.conf 如下:
```
[request_definition]
r = sub, obj, act
[policy_definition]
p = sub, obj, act
# RBAC角色继承关系的定义
[role_definition]
g = _, _
[policy_effect]
e = some(where (p.eft == allow))
[matchers]
m = g(r.sub, p.sub) && keyMatch2(r.obj, p.obj) && regexMatch(r.act, p.act)
```
### 初始化一个Casbin enforcer
```php
use Casbin\Enforcer;
use CasbinAdapter\Database\Adapter;
$adapter = Adapter::newAdapter([
'type' => 'mysql',
'hostname' => '127.0.0.1',
'database' => 'test',
'username' => 'root',
]);
$enforcer = new Enforcer('path/to/model.conf', $adapter);
```
### 添加策略
给alice和bob分配角色：
```php
// alice has the admin role
$enforcer->addRoleForUser('alice', 'admin');
// bob has the member role
$enforcer->addRoleForUser('bob', 'member');
```
给member角色分配权限，`member` 角色仅对`foo`资源有查看权限:
```php
$enforcer->addPermissionForUser('member', '/foo', 'GET');
$enforcer->addPermissionForUser('member', '/foo/:id', 'GET');
```
`admin`角色对`foo`拥有增删改查权限：
```php
// admin inherits all permissions of member
$enforcer->addRoleForUser('admin', 'member');
$enforcer->addPermissionForUser('admin', '/foo', 'POST');
$enforcer->addPermissionForUser('admin', '/foo/:id', 'PUT');
$enforcer->addPermissionForUser('admin', '/foo/:id', 'DELETE');
```
分配完角色和权限后，数据库中的策略规则大致如下：
```
g, alice, admin
g, bob, member
p, memeber, /foo, GET
p, memeber, /foo/:id, GET
g, admin, member
p, admin, /foo, POST
p, admin, /foo/:id, PUT
p, admin, /foo/:id, DELETE
```
### 验证权限
`alice` 具有`admin`角色，继承`admin`和`member`两个角色的全部权限.
```php
$enforcer->enforce('alice', '/foo', 'GET'); // true
$enforcer->enforce('alice', '/foo', 'GET'); // true
$enforcer->enforce('alice', '/foo', 'POST'); // true
$enforcer->enforce('alice', '/foo/1', 'PUT'); // true
$enforcer->enforce('alice', '/foo/1', 'DELETE'); // true
```
`bob` 具有`member`角色, 只继承`member`的权限.
```php
$enforcer->enforce('bob', '/foo', 'GET'); // true
$enforcer->enforce('bob', '/foo', 'GET'); // true
$enforcer->enforce('bob', '/foo', 'POST'); // false
$enforcer->enforce('bob', '/foo/1', 'PUT'); // false
$enforcer->enforce('bob', '/foo/1', 'DELETE'); // false
```
