casbin/json-adapter

JSON adapter for Casbin

JSON Adapter

JSON Adapter is the JSON (JavaScript Object Notation) adapter for Casbin. With this library, Casbin can load policy from JSON string or save policy to it.

Installation

go get github.com/casbin/json-adapter/v2

Simple Example

package main

import (
	"github.com/casbin/casbin/v2"
	"github.com/casbin/json-adapter/v2"
)

func main() {
	// Initialize a JSON adapter and use it in a Casbin enforcer:
	b := []byte{} // b stores Casbin policy in JSON bytes.
	a := jsonadapter.NewAdapter(&b) // Use b as the data source. 
	e, _ := casbin.NewEnforcer("examples/rbac_model.conf", a)
	
	// Load the policy from JSON bytes b.
	e.LoadPolicy()
	
	// Check the permission.
	e.Enforce("alice", "data1", "read")
	
	// Modify the policy.
	// e.AddPolicy(...)
	// e.RemovePolicy(...)
	
	// Save the policy back to JSON bytes b.
	e.SavePolicy()
}

Policy JSON

The following illustrates the expected JSON format for a policy. The rbac_policy.json has the same policy found in rbac_policy.csv.

[
  {"PType":"p","V0":"alice","V1":"data1","V2":"read"},
  {"PType":"p","V0":"bob","V1":"data2","V2":"write"},
  {"PType":"p","V0":"data2_admin","V1":"data2","V2":"read"},
  {"PType":"p","V0":"data2_admin","V1":"data2","V2":"write"},
  {"PType":"g","V0":"alice","V1":"data2_admin"}
]

Getting Help

• Casbin

License

This project is under Apache 2.0 License. See the LICENSE file for the full license text.

json-adapter's Issues

Update the installation docs

If you install the adapter using the command go get github.com/casbin/json-adapter, it's not compatible with the latest casbin v2. Also, the current version module name is github.com/casbin/json-adapter/v2. The installation guide should be updated to go get github.com/casbin/json-adapter/v2.

Switch to GitHub Actions CI and add semantic-release

Refer to: https://github.com/search?q=org%3Acasbin+Switch+to+GitHub+Actions+CI&type=issues

panic: runtime error: invalid memory address or nil pointer dereference

Getting this error for every enforcer method
please fix me if I'm doing something wrong.

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x10 pc=0x42722d]

goroutine 1 [running]:
github.com/casbin/casbin/v2.(*Enforcer).LoadPolicy(0x0)
        C:/Users/Admin/go/pkg/mod/github.com/casbin/casbin/[email protected]/enforcer.go:284 +0x4d
main.main()
        T:/dev/go_json_casbin_tesdt/main.go:16 +0xe7
exit status 2  

package main

import (
	"github.com/casbin/casbin/v2"
	"github.com/casbin/json-adapter/v2"
)

func main() {
	b := []byte{}
	a := jsonadapter.NewAdapter(&b)
	e, _ := casbin.NewEnforcer("examples/rbac_model.conf", a)
	e.LoadPolicy()
}

Could not get this adapter working via the example, without an existing policy to load

I am using this adapter to essentially have an in-memory policy. I was unable to continue without pre-seeding the byte buffer with []:

func (a *Adapter) loadFromBuffer() error {
	var policy []CasbinRule
	err := json.Unmarshal(*a.source, &policy)
	if err == nil {
		a.policy = policy
	}
	return err
}

err is unexpected end of JSON input which is expected given the code.