文章目录
- 0. 背景
- 1. 准备工作
- 2. 权限配置以及`增删改查`
- 2.1 策略和组使用规范
- 2.2 用户以及组关系的增删改查
- 2.2.1 获取所有用户以及关联的角色
- 2.2.2 角色组中添加用户
- 2.2.3 角色组中删除用户
- 2.3 角色组权限的`增删改查`
- 2.3.1 获取所有角色组权限
- 2.3.2 创建角色组权限
- 2.3.3 修改角色组权限
- 2.3.4 删除角色组权限
- 2.3.5 验证用户权限
- 3. 测试以及完整代码
- 3.1 casbin_service.go
- 3.2 casbin_service_test.go
- 3.3测试结果
- 4. 结语
0. 背景
Casbin是用于Golang项目的功能强大且高效的开源访问控制库。
强大通用也意味着概念和配置较多,具体到实际应用(以Gin Web框架开发)需要解决以下问题:
- 权限配置的存储,以及
增删改查
- Gin框架的中间件如何实现
经过一番摸索实践出经验,计划分为三个章节,循序渐进的介绍使用方法
- Casbin概念介绍以及库使用
- 使用Gorm存储Casbin权限配置以及
增删改查
- 实现Gin鉴权中间件
1. 准备工作
接上一章,略改进一下,将
model.conf
文件内容存储到go字符串中,最终代码如下:
package mainimport ("log""github.com/casbin/casbin/v2""github.com/casbin/casbin/v2/model"gormadapter "github.com/casbin/gorm-adapter/v3""github.com/glebarez/sqlite""gorm.io/gorm"
)func main() {db, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{})if err != nil {panic("failed to connect database")}a, err := gormadapter.NewAdapterByDB(db)if err != nil {panic("new gorm adapter error: " + err.Error())}m, err := model.NewModelFromString(`[request_definition]
r = sub, obj, act[policy_definition]
p = sub, obj, act[role_definition]
g = _, _[policy_effect]
e = some(where (p.eft == allow))[matchers]
m = g(r.sub, p.sub) && keyMatch2(r.obj,p.obj) && r.act == p.act`)if err != nil {panic("new model error: " + err.Error())}e, err := casbin.NewEnforcer(m, a)if err != nil {panic("new casbin enforcer error: " + err.Error())}e.LoadPolicy()// 添加策略ok, err := e.AddPolicy("admin", "/api/user", "GET")log.Println("add admin /api/user GET: ", ok, err)ok, err = e.AddGroupingPolicy("leo", "admin")log.Println("add leo to admin group: ", ok, err)e.SavePolicy()ok, err = e.Enforce("leo", "/api/user", "GET")log.Println("leo GET /api/user :", ok, err)ok, err = e.Enforce("leo", "/api/user", "DELETE")log.Println("leo DELETE /api/user :", ok, err)
}
上述代码默认使用的
gormadapter.CasbinRule
对应的Go结构和数据库表如下
type CasbinRule struct {ID uint `gorm:"primaryKey;autoIncrement"`Ptype string `gorm:"size:100"`V0 string `gorm:"size:100"`V1 string `gorm:"size:100"`V2 string `gorm:"size:100"`V3 string `gorm:"size:100"`V4 string `gorm:"size:100"`V5 string `gorm:"size:100"`
}
2. 权限配置以及增删改查
以上准备知识,仅了解和casbin基本操作以及如何配合gorm存储到DB中,还需要完善权限,以及提供
增删改查
操作
2.1 策略和组使用规范
casbin的policy十分灵活,具体到自己业务使用中,我这里按以下两条规则使用,基本能满足业务需求
- 所有策略只针对角色组设置
- 用户关联到组(一个用户可以有多个组)
如下,两个角色组
admin
和user
组,admin组
能查询
和删除
用户,user组
只能查询用户
ptype | v0 | v1 | v2 | v3 | v4 | v5 |
---|---|---|---|---|---|---|
p | admin | /api/user | GET | |||
p | admin | /api/user | DELETE | |||
p | user | /api/user | GET | |||
… | … | … | ||||
g | leo | admin | ||||
g | leo2 | user |
基础代码如下,下一节给
CasbinService
添加增删改查
功能
package mainimport ("github.com/casbin/casbin/v2""github.com/casbin/casbin/v2/model"gormadapter "github.com/casbin/gorm-adapter/v3""gorm.io/gorm"
)type CasbinService struct {enforcer *casbin.Enforceradapter *gormadapter.Adapter
}func NewCasbinService(db *gorm.DB) (*CasbinService, error) {a, err := gormadapter.NewAdapterByDB(db)if err != nil {return nil, err}m, err := model.NewModelFromString(`[request_definition]r = sub, obj, act[policy_definition]p = sub, obj, act[role_definition]g = _, _[policy_effect]e = some(where (p.eft == allow))[matchers]m = g(r.sub, p.sub) && keyMatch2(r.obj,p.obj) && r.act == p.act`)if err != nil {return nil, err}e, err := casbin.NewEnforcer(m, a)if err != nil {return nil, err}return &CasbinService{adapter: a, enforcer: e}, nil
}
2.2 用户以及组关系的增删改查
2.2.1 获取所有用户以及关联的角色
根据
2.1
中示范数据,预期输出
[{"username": "leo","roleNames": ["admin"]
}, {"username": "leo2","roleNames": ["user"]
}]
获取所有用户以及关联的角色代码片段
type User struct {UserName stringRoleNames []string
}// 获取所有用户以及关联的角色
func (c *CasbinService) GetUsers() (users []User) {p := c.enforcer.GetGroupingPolicy()usernameUser := make(map[string]*User, 0)for _, _p := range p {username, usergroup := _p[0], _p[1]if v, ok := usernameUser[username]; ok {usernameUser[username].RoleNames = append(v.RoleNames, usergroup)} else {usernameUser[username] = &User{UserName: username, RoleNames: []string{usergroup}}}}for _, v := range usernameUser {users = append(users, *v)}return
}
2.2.2 角色组中添加用户
// 角色组中添加用户, 没有组默认创建
func (c *CasbinService) UpdateUserRole(username, rolename string) error {_, err := c.enforcer.AddGroupingPolicy(username, rolename)return err
}
2.2.3 角色组中删除用户
// 角色组中删除用户
func (c *CasbinService) DeleteUserRole(username, rolename string) error {_, err := c.enforcer.RemoveGroupingPolicy(username, rolename)return err
}
2.3 角色组权限的增删改查
2.3.1 获取所有角色组权限
根据
2.1
中示范数据,预期输出形式
[{"roleName": "admin","url": "/api/user","method": "DELETE"
}, {"roleName": "admin","url": "/api/user","method": "GET"
}, {"roleName": "user","url": "/api/user","method": "GET"
}]
获取所有角色组权限
```go
// (RoleName, Url, Method) 对应于 `CasbinRule` 表中的 (v0, v1, v2)
type RolePolicy struct {RoleName string `gorm:"column:v0"`Url string `gorm:"column:v1"`Method string `gorm:"column:v2"`
}// 获取所有角色组权限
func (c *CasbinService) GetRolePolicy() (roles []RolePolicy, err error) {err = c.adapter.GetDb().Model(&gormadapter.CasbinRule{}).Where("ptype = 'p'").Find(&roles).Errorif err != nil {return nil, err}return
}
2.3.2 创建角色组权限
// 创建角色组权限, 已有的会忽略
func (c *CasbinService) CreateRolePolicy(r RolePolicy) error {// 不直接操作数据库,利用enforcer简化操作err := c.enforcer.LoadPolicy()if err != nil {return err}_, err = c.enforcer.AddPolicy(r.RoleName, r.Url, r.Method)if err != nil {return err}return c.enforcer.SavePolicy()
}
2.3.3 修改角色组权限
// 修改角色组权限
func (c *CasbinService) UpdateRolePolicy(old, new RolePolicy) error {_, err := c.enforcer.UpdatePolicy([]string{old.RoleName, old.Url, old.Method},[]string{new.RoleName, new.Url, new.Method})if err != nil {return err}return c.enforcer.SavePolicy()
}
2.3.4 删除角色组权限
// 删除角色组权限
func (c *CasbinService) DeleteRolePolicy(r RolePolicy) error {_, err := c.enforcer.RemovePolicy(r.RoleName, r.Url, r.Method)if err != nil {return err}return c.enforcer.SavePolicy()
}
2.3.5 验证用户权限
// 验证用户权限
func (c *CasbinService) CanAccess(username, url, method string) (ok bool, err error) {return c.enforcer.Enforce(username, url, method)
}
3. 测试以及完整代码
3.1 casbin_service.go
package mainimport ("github.com/casbin/casbin/v2""github.com/casbin/casbin/v2/model"gormadapter "github.com/casbin/gorm-adapter/v3""gorm.io/gorm"
)/*
按如下约定:1. 所有策略只针对角色组设置2. 用户关联到组(一个用户可以有多个组)
+-------+-------+-----------+--------+----+----+----+
| ptype | v0 | v1 | v2 | v3 | v4 | v5 |
+-------+-------+-----------+--------+----+----+----+
| p | admin | /api/user | GET | | | |
+-------+-------+-----------+--------+----+----+----+
| p | admin | /api/user | DELETE | | | |
+-------+-------+-----------+--------+----+----+----+
| p | user | /api/user | GET | | | |
+-------+-------+-----------+--------+----+----+----+
| ... | ... | ... | | | | |
+-------+-------+-----------+--------+----+----+----+
| g | leo | admin | | | | |
+-------+-------+-----------+--------+----+----+----+
| g | leo2 | admin | | | | |
+-------+-------+-----------+--------+----+----+----+
| g | leo3 | user | | | | |
+-------+-------+-----------+--------+----+----+----+
*/
type CasbinService struct {enforcer *casbin.Enforceradapter *gormadapter.Adapter
}func NewCasbinService(db *gorm.DB) (*CasbinService, error) {a, err := gormadapter.NewAdapterByDB(db)if err != nil {return nil, err}m, err := model.NewModelFromString(`[request_definition]r = sub, obj, act[policy_definition]p = sub, obj, act[role_definition]g = _, _[policy_effect]e = some(where (p.eft == allow))[matchers]m = g(r.sub, p.sub) && keyMatch2(r.obj,p.obj) && r.act == p.act`)if err != nil {return nil, err}e, err := casbin.NewEnforcer(m, a)if err != nil {return nil, err}return &CasbinService{adapter: a, enforcer: e}, nil
}// (RoleName, Url, Method) 对应于 `CasbinRule` 表中的 (v0, v1, v2)
type RolePolicy struct {RoleName string `gorm:"column:v0"`Url string `gorm:"column:v1"`Method string `gorm:"column:v2"`
}// 获取所有角色组权限
func (c *CasbinService) GetRolePolicy() (roles []RolePolicy, err error) {err = c.adapter.GetDb().Model(&gormadapter.CasbinRule{}).Where("ptype = 'p'").Find(&roles).Errorif err != nil {return nil, err}return
}// 创建角色组权限, 已有的会忽略
func (c *CasbinService) CreateRolePolicy(r RolePolicy) error {// 不直接操作数据库,利用enforcer简化操作err := c.enforcer.LoadPolicy()if err != nil {return err}_, err = c.enforcer.AddPolicy(r.RoleName, r.Url, r.Method)if err != nil {return err}return c.enforcer.SavePolicy()
}// 修改角色组权限
func (c *CasbinService) UpdateRolePolicy(old, new RolePolicy) error {_, err := c.enforcer.UpdatePolicy([]string{old.RoleName, old.Url, old.Method},[]string{new.RoleName, new.Url, new.Method})if err != nil {return err}return c.enforcer.SavePolicy()
}// 删除角色组权限
func (c *CasbinService) DeleteRolePolicy(r RolePolicy) error {_, err := c.enforcer.RemovePolicy(r.RoleName, r.Url, r.Method)if err != nil {return err}return c.enforcer.SavePolicy()
}type User struct {UserName stringRoleNames []string
}// 获取所有用户以及关联的角色
func (c *CasbinService) GetUsers() (users []User) {p := c.enforcer.GetGroupingPolicy()usernameUser := make(map[string]*User, 0)for _, _p := range p {username, usergroup := _p[0], _p[1]if v, ok := usernameUser[username]; ok {usernameUser[username].RoleNames = append(v.RoleNames, usergroup)} else {usernameUser[username] = &User{UserName: username, RoleNames: []string{usergroup}}}}for _, v := range usernameUser {users = append(users, *v)}return
}// 角色组中添加用户, 没有组默认创建
func (c *CasbinService) UpdateUserRole(username, rolename string) error {_, err := c.enforcer.AddGroupingPolicy(username, rolename)return err
}// 角色组中删除用户
func (c *CasbinService) DeleteUserRole(username, rolename string) error {_, err := c.enforcer.RemoveGroupingPolicy(username, rolename)return err
}// 验证用户权限
func (c *CasbinService) CanAccess(username, url, method string) (ok bool, err error) {return c.enforcer.Enforce(username, url, method)
}
3.2 casbin_service_test.go
package mainimport ("testing""github.com/glebarez/sqlite""gorm.io/gorm"
)func TestCasbinService(t *testing.T) {db, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{})if err != nil {panic("failed to connect database")}s, err := NewCasbinService(db)if err != nil {t.Fatalf("new service error: %v", err)}// 创建个用户,分别关联到`admin`和`user`组, `leo2`既是`admin`组又是`user`组t.Logf("create user: leo with group: admin result: %v", s.UpdateUserRole("leo", "admin"))t.Logf("create user: leo with group: admin result: %v", s.UpdateUserRole("leo2", "admin"))t.Logf("create user: leo with group: admin result: %v", s.UpdateUserRole("leo2", "user"))t.Log()t.Logf("users is: %v\n", s.GetUsers())// 针对`admin`和`user`组创建三条策略t.Log("create admin /api/user GET: ", s.CreateRolePolicy(RolePolicy{RoleName: "admin", Url: "/api/user", Method: "GET"}))t.Log("create admin /api/user DELETE: ", s.CreateRolePolicy(RolePolicy{RoleName: "admin", Url: "/api/user", Method: "DELETE"}))t.Log("create user /api/user GET: ", s.CreateRolePolicy(RolePolicy{RoleName: "user", Url: "/api/user", Method: "GET"}))t.Log("all policy is: ")t.Log(s.GetRolePolicy())t.Log("delete admin /api/user GET", s.DeleteRolePolicy(RolePolicy{RoleName: "admin", Url: "/api/user", Method: "GET"}))
}
3.3测试结果
4. 结语
基本的权限模型设计以及操作函数均已设计正常, 下一章开始结合
gin
框架设计一个中间件, 实现casbin权限验证