Casbin

Casbin middleware for Fiber.

Note: Requires Go 1.18 and above

Install

go get -u github.com/gofiber/fiber/v2
go get -u github.com/gofiber/contrib/casbin

choose an adapter from here

go get -u github.com/casbin/xorm-adapter

Signature

casbin.New(config ...casbin.Config) *casbin.Middleware

Config

Property	Type	Description	Default
ModelFilePath	string	Model file path	"./model.conf"
PolicyAdapter	persist.Adapter	Database adapter for policies	./policy.csv
Enforcer	*casbin.Enforcer	Custom casbin enforcer	Middleware generated enforcer using ModelFilePath & PolicyAdapter
Lookup	func(*fiber.Ctx) string	Look up for current subject	""
Unauthorized	func(*fiber.Ctx) error	Response body for unauthorized responses	Unauthorized
Forbidden	func(*fiber.Ctx) error	Response body for forbidden responses	Forbidden

Examples

• Gorm Adapter
• File Adapter

CustomPermission

package main

import (
  "github.com/gofiber/fiber/v2"
  "github.com/gofiber/contrib/casbin"
  _ "github.com/go-sql-driver/mysql"
  "github.com/casbin/xorm-adapter/v2"
)

func main() {
  app := fiber.New()

  authz := casbin.New(casbin.Config{
      ModelFilePath: "path/to/rbac_model.conf",
      PolicyAdapter: xormadapter.NewAdapter("mysql", "root:@tcp(127.0.0.1:3306)/"),
      Lookup: func(c *fiber.Ctx) string {
          // fetch authenticated user subject
      },
  })

  app.Post("/blog",
      authz.RequiresPermissions([]string{"blog:create"}, casbin.WithValidationRule(casbin.MatchAllRule)),
      func(c *fiber.Ctx) error {
        // your handler
      },
  )
  
  app.Delete("/blog/:id",
    authz.RequiresPermissions([]string{"blog:create", "blog:delete"}, casbin.WithValidationRule(casbin.AtLeastOneRule)),
    func(c *fiber.Ctx) error {
      // your handler
    },
  )

  app.Listen(":8080")
}

RoutePermission

package main

import (
  "github.com/gofiber/fiber/v2"
  "github.com/gofiber/contrib/casbin"
  _ "github.com/go-sql-driver/mysql"
  "github.com/casbin/xorm-adapter/v2"
)

func main() {
  app := fiber.New()

  authz := casbin.New(casbin.Config{
      ModelFilePath: "path/to/rbac_model.conf",
      PolicyAdapter: xormadapter.NewAdapter("mysql", "root:@tcp(127.0.0.1:3306)/"),
      Lookup: func(c *fiber.Ctx) string {
          // fetch authenticated user subject
      },
  })

  // check permission with Method and Path
  app.Post("/blog",
    authz.RoutePermission(),
    func(c *fiber.Ctx) error {
      // your handler
    },
  )

  app.Listen(":8080")
}

RoleAuthorization

package main

import (
  "github.com/gofiber/fiber/v2"
  "github.com/gofiber/contrib/casbin"
  _ "github.com/go-sql-driver/mysql"
  "github.com/casbin/xorm-adapter/v2"
)

func main() {
  app := fiber.New()

  authz := casbin.New(casbin.Config{
      ModelFilePath: "path/to/rbac_model.conf",
      PolicyAdapter: xormadapter.NewAdapter("mysql", "root:@tcp(127.0.0.1:3306)/"),
      Lookup: func(c *fiber.Ctx) string {
          // fetch authenticated user subject
      },
  })
  
  app.Put("/blog/:id",
    authz.RequiresRoles([]string{"admin"}),
    func(c *fiber.Ctx) error {
      // your handler
    },
  )

  app.Listen(":8080")
}