Casbin

Casbin middleware for Fiber.

Compatible with Fiber v3.

This middleware targets Casbin v3. Casbin v2 is no longer supported here; if you still need it, pin the previous major (github.com/gofiber/contrib/v3/casbin at its last v1 tag). Migrating from Casbin v2 to v3 is mostly an import-path change; see the Casbin upgrade guide.

Go version support

We only support the latest two versions of Go. Visit https://go.dev/doc/devel/release for more information.

Install

go get -u github.com/gofiber/fiber/v3
go get -u github.com/gofiber/contrib/v3/casbin/v2

choose an adapter from here

go get -u github.com/casbin/gorm-adapter/v3

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/v3"
  "github.com/gofiber/contrib/v3/casbin/v2"
  _ "github.com/go-sql-driver/mysql"
  gormadapter "github.com/casbin/gorm-adapter/v3"
)

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

  adapter, _ := gormadapter.NewAdapter("mysql", "root:@tcp(127.0.0.1:3306)/")
  authz := casbin.New(casbin.Config{
      ModelFilePath: "path/to/rbac_model.conf",
      PolicyAdapter: adapter,
      Lookup: func(c fiber.Ctx) string {
          return "" // 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/v3"
  "github.com/gofiber/contrib/v3/casbin/v2"
  _ "github.com/go-sql-driver/mysql"
  gormadapter "github.com/casbin/gorm-adapter/v3"
)

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

  adapter, _ := gormadapter.NewAdapter("mysql", "root:@tcp(127.0.0.1:3306)/")
  authz := casbin.New(casbin.Config{
      ModelFilePath: "path/to/rbac_model.conf",
      PolicyAdapter: adapter,
      Lookup: func(c fiber.Ctx) string {
          return "" // 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/v3"
  "github.com/gofiber/contrib/v3/casbin/v2"
  _ "github.com/go-sql-driver/mysql"
  gormadapter "github.com/casbin/gorm-adapter/v3"
)

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

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

  app.Put("/blog/:id",
    authz.RequiresRoles([]string{"admin"}),
    func(c fiber.Ctx) error {
      // your handler
    },
  )

  app.Listen(":8080")
}