natswatcher

README

casbin-nats-watcher

Casbin watcher implementation with Nats.io

Installation

go get github.com/HandleKun/casbin-nats-watcher

Usage

import (
    natswatcher "github.com/HandleKun/casbin-nats-watcher"
    "github.com/casbin/casbin/v2"
)

func main() {
    watcher, _ := natswatcher.NewWatcher("http://nats-endpoint", "my-policy-subject")

    enforcer, _ := casbin.NewSyncedEnforcer("model.conf", "policy.csv")
    enforcer.SetWatcher(watcher)
    
    watcher.SetUpdateCallback(func(m string) {
        enforcer.LoadPolicy()
    })
}

Related pojects

• Casbin
• Nats.io

Additional Usage Examples

For real-world example visit Tweek.

License

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

Documentation

Index

• func NewWatcher(endpoint string, policyUpdatedSubject string, options ...nats.Option) (persist.Watcher, error)
• type Watcher
  • func (w *Watcher) Close()
  • func (w *Watcher) SetUpdateCallback(callback func(string)) error
  • func (w *Watcher) Update() error

Functions

func NewWatcher

func NewWatcher(endpoint string, policyUpdatedSubject string, options ...nats.Option) (persist.Watcher, error)

NewWatcher creates new Nats watcher. Parameters:

• endpoint Endpoint of Nats server
• policyUpdatedSubject Nats subject that sends message when policy was updated externally. It leads to call of callback
• options Options to connect Nats like user, password, etc.

Types

type Watcher

type Watcher struct {
	// contains filtered or unexported fields
}

Watcher implements persist.Watcher interface

func (*Watcher) Close

func (w *Watcher) Close()

Close stops and releases the watcher, the callback function will not be called any more.

func (*Watcher) SetUpdateCallback

func (w *Watcher) SetUpdateCallback(callback func(string)) error

SetUpdateCallback sets the callback function that the watcher will call when the policy in DB has been changed by other instances. A classic callback is Enforcer.LoadPolicy().

func (*Watcher) Update

func (w *Watcher) Update() error

Update calls the update callback of other instances to synchronize their policy. It is usually called after changing the policy in DB, like Enforcer.SavePolicy(), Enforcer.AddPolicy(), Enforcer.RemovePolicy(), etc.