psqlwatcher

README

Casbin Postgres Watcher

---

A WatcherEX implementation for Casbin based on PostgreSQL

Installation

go get github.com/IguteChung/casbin-psql-watcher

Example

package main

import (
	"context"
	"fmt"

	psqlwatcher "github.com/IguteChung/casbin-psql-watcher"
	"github.com/casbin/casbin/v2"
)

func main() {
	// prepare the watcher with local psql server.
	// for demo purpose, enable NotifySelf to receive a local change callback.
	conn := "host=localhost user=postgres password=postgres dbname=postgres port=5432"
	w, _ := psqlwatcher.NewWatcherWithConnString(context.Background(), conn,
		psqlwatcher.Option{NotifySelf: true, Verbose: true})

	// prepare the enforcer.
	e, _ := casbin.NewEnforcer("../testdata/rbac_model.conf", "../testdata/rbac_policy.csv")

	// set the watcher for enforcer.
	_ = e.SetWatcher(w)

	// set the default callback to handle policy changes.
	_ = w.SetUpdateCallback(psqlwatcher.DefaultCallback(e))

	// update the policy and notify other enforcers.
	_ = e.SavePolicy()

	// wait for callback.
	fmt.Scanln()
}

Dependency

• Casbin
• pgx

Documentation

Index

• func DefaultCallback(e casbin.IEnforcer) func(string)
• type MSG
• type Option
• type UpdateType
• type Watcher
  • func NewWatcherWithConnString(ctx context.Context, connString string, opt Option) (*Watcher, error)
  • func NewWatcherWithPool(ctx context.Context, pool *pgxpool.Pool, opt Option) (*Watcher, error)
  • func (w *Watcher) Close()
  • func (w *Watcher) GetChannel() string
  • func (w *Watcher) GetLocalID() string
  • func (w *Watcher) GetNotifySelf() bool
  • func (w *Watcher) GetVerbose() bool
  • func (w *Watcher) SetUpdateCallback(callback func(string)) error
  • func (w *Watcher) Update() error
  • func (w *Watcher) UpdateForAddPolicies(sec string, ptype string, rules ...[]string) error
  • func (w *Watcher) UpdateForAddPolicy(sec, ptype string, params ...string) error
  • func (w *Watcher) UpdateForRemoveFilteredPolicy(sec, ptype string, fieldIndex int, fieldValues ...string) error
  • func (w *Watcher) UpdateForRemovePolicies(sec string, ptype string, rules ...[]string) error
  • func (w *Watcher) UpdateForRemovePolicy(sec, ptype string, params ...string) error
  • func (w *Watcher) UpdateForSavePolicy(model model.Model) error
  • func (w *Watcher) UpdateForUpdatePolicies(sec string, ptype string, oldRules, newRules [][]string) error
  • func (w *Watcher) UpdateForUpdatePolicy(sec string, ptype string, oldRule, newRule []string) error

Functions

func DefaultCallback

func DefaultCallback(e casbin.IEnforcer) func(string)

DefaultCallback defines the generic implementation for WatcherEX interface.

Types

type MSG

type MSG struct {
	Method      UpdateType `json:"method"`
	ID          string     `json:"id"`
	Sec         string     `json:"sec,omitempty"`
	Ptype       string     `json:"ptype,omitempty"`
	OldRules    [][]string `json:"old_rules,omitempty"`
	NewRules    [][]string `json:"new_rules,omitempty"`
	FieldIndex  int        `json:"field_index,omitempty"`
	FieldValues []string   `json:"field_values,omitempty"`
}

MSG defines the payload for message.

type Option

type Option struct {
	// Channel defines which psql channel to use.
	// use default channel if not specified.
	Channel string
	// Verbose indicate whether to output info log.
	Verbose bool
	// LocalID indicates the watcher's local ID, used to ignore self update event.
	// generate a random id if not specified.
	LocalID string
	// NotifySelf will notify change to the same watcher to do the update.
	// only for testing or debug usage.
	NotifySelf bool
}

Option is used for configure watcher.

type UpdateType

type UpdateType string

UpdateType defines the type of update operation.

const (
	Update                        UpdateType = "Update"
	UpdateForAddPolicy            UpdateType = "UpdateForAddPolicy"
	UpdateForRemovePolicy         UpdateType = "UpdateForRemovePolicy"
	UpdateForRemoveFilteredPolicy UpdateType = "UpdateForRemoveFilteredPolicy"
	UpdateForSavePolicy           UpdateType = "UpdateForSavePolicy"
	UpdateForAddPolicies          UpdateType = "UpdateForAddPolicies"
	UpdateForRemovePolicies       UpdateType = "UpdateForRemovePolicies"
	UpdateForUpdatePolicy         UpdateType = "UpdateForUpdatePolicy"
	UpdateForUpdatePolicies       UpdateType = "UpdateForUpdatePolicies"
)

all types of Update.

type Watcher

type Watcher struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

Watcher implements casbin Watcher and WatcherEX to sync multiple casbin enforcer.

func NewWatcherWithConnString

func NewWatcherWithConnString(ctx context.Context, connString string, opt Option) (*Watcher, error)

NewWatcherWithConnString creates a Watcher with pgx connection string.

func NewWatcherWithPool

func NewWatcherWithPool(ctx context.Context, pool *pgxpool.Pool, opt Option) (*Watcher, error)

NewWatcherWithPool creates a Watcher with pgx pool.

func (*Watcher) Close

func (w *Watcher) Close()

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

func (*Watcher) GetChannel

func (w *Watcher) GetChannel() string

GetChannel gets the channel for the option.

func (*Watcher) GetLocalID

func (w *Watcher) GetLocalID() string

GetLocalID gets the local ID for the option.

func (*Watcher) GetNotifySelf

func (w *Watcher) GetNotifySelf() bool

GetNotifySelf gets the NotifySelf for the option.

func (*Watcher) GetVerbose

func (w *Watcher) GetVerbose() bool

GetVerbose gets the verbose for the option.

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.

func (*Watcher) UpdateForAddPolicies

func (w *Watcher) UpdateForAddPolicies(sec string, ptype string, rules ...[]string) error

UpdateForAddPolicies calls the update callback of other instances to synchronize their policy. It is called after Enforcer.AddPolicies()

func (*Watcher) UpdateForAddPolicy

func (w *Watcher) UpdateForAddPolicy(sec, ptype string, params ...string) error

UpdateForAddPolicy calls the update callback of other instances to synchronize their policy. It is called after Enforcer.AddPolicy()

func (*Watcher) UpdateForRemoveFilteredPolicy

func (w *Watcher) UpdateForRemoveFilteredPolicy(sec, ptype string, fieldIndex int, fieldValues ...string) error

UpdateForRemoveFilteredPolicy calls the update callback of other instances to synchronize their policy. It is called after Enforcer.RemoveFilteredNamedGroupingPolicy()

func (*Watcher) UpdateForRemovePolicies

func (w *Watcher) UpdateForRemovePolicies(sec string, ptype string, rules ...[]string) error

UpdateForRemovePolicies calls the update callback of other instances to synchronize their policy. It is called after Enforcer.RemovePolicies()

func (*Watcher) UpdateForRemovePolicy

func (w *Watcher) UpdateForRemovePolicy(sec, ptype string, params ...string) error

UpdateForRemovePolicy calls the update callback of other instances to synchronize their policy. It is called after Enforcer.RemovePolicy()

func (*Watcher) UpdateForSavePolicy

func (w *Watcher) UpdateForSavePolicy(model model.Model) error

UpdateForSavePolicy calls the update callback of other instances to synchronize their policy. It is called after Enforcer.RemoveFilteredNamedGroupingPolicy()

func (*Watcher) UpdateForUpdatePolicies

func (w *Watcher) UpdateForUpdatePolicies(sec string, ptype string, oldRules, newRules [][]string) error

UpdateForUpdatePolicies calls the update callback of other instances to synchronize their policy. It is called after Enforcer.UpdatePolicies()

func (*Watcher) UpdateForUpdatePolicy

func (w *Watcher) UpdateForUpdatePolicy(sec string, ptype string, oldRule, newRule []string) error

UpdateForUpdatePolicy calls the update callback of other instances to synchronize their policy. It is called after Enforcer.UpdatePolicy()