Watchers
We support to use distributed messaging systems like etcd to keep consistence between multiple Casbin enforcer instances. So our users can concurrently use multiple Casbin enforcers to handle large number of permission checking requests.
Similar to policy storage adapters, we don't put watcher code in the main library. Any support for a new messaging system should be implemented as a watcher. A complete list of Casbin watchers is provided as below. Any 3rd-party contribution on a new watcher is welcomed, please inform us and I will put it in this list:)
| Watcher | Type | Author | Description |
|---|---|---|---|
| Etcd Watcher | KV store | Casbin | Watcher for etcd |
| Redis Watcher | KV store | Casbin | Watcher for Redis |
| Redis Watcher | KV store | @billcobbler | Watcher for Redis |
| TiKV Watcher | KV store | Casbin | Watcher for TiKV |
| Kafka Watcher | Messaging system | @wgarunap | Watcher for Apache Kafka |
| NATS Watcher | Messaging system | Soluto | Watcher for NATS |
| ZooKeeper Watcher | Messaging system | Grepsr | Watcher for Apache ZooKeeper |
| NATS, RabbitMQ, GCP Pub/Sub, AWS SNS & SQS, Kafka, InMemory | Messaging System | @rusenask | Watcher based on Go Cloud Dev Kit that works with leading cloud providers and self-hosted infrastructure |
| RocketMQ Watcher | Messaging system | @fmyxyz | Watcher for Apache RocketMQ |
| Watcher | Type | Author | Description |
|---|---|---|---|
| Etcd Adapter | KV store | @mapleafgo | Watcher for etcd |
| Redis Watcher | KV store | Casbin | Watcher for Redis |
| Kafka Watcher | Messaging system | Casbin | Watcher for Apache Kafka |
| Watcher | Type | Author | Description |
|---|---|---|---|
| Etcd Watcher | KV store | Casbin | Watcher for etcd |
| Redis Watcher | KV store | Casbin | Watcher for Redis |
| Pub/Sub Watcher | Messaging system | Casbin | Watcher for Google Cloud Pub/Sub |
| Postgres Watcher | Database | Matteo Collina | Watcher for PostgreSQL |
| Watcher | Type | Author | Description |
|---|---|---|---|
| Redis Watcher | KV store | ScienceLogic | Watcher for Redis |
| PostgreSQL Watcher | Database | Casbin | Watcher for PostgreSQL |
| Watcher | Type | Author | Description |
|---|---|---|---|
| Redis Watcher | KV store | @Sbou | Watcher for Redis |
| Watcher | Type | Author | Description |
|---|---|---|---|
| Redis Watcher | KV store | CasbinRuby | Watcher for Redis |
| RabbitMQ Watcher | Messaging system | CasbinRuby | Watcher for RabbitMQ |
| Watcher | Type | Author | Description |
|---|---|---|---|
| Redis Watcher | KV store | Tinywan | Watcher for Redis |
WatcherEx
In order to support incremental synchronization between multiple instances, we provide the WatcherEx interface. We hope it can notify other instances when the policy changes, but there is currently no implementation of WatcherEx. We recommend that you use dispatcher to achieve this.
Compared with Watcher interface, WatcherEx can distinguish what type of update action is received, e.g., AddPolicy and RemovePolicy.
WatcherEx Apis:
| api | description |
|---|---|
| SetUpdateCallback(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(). |
| 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. |
| Close() | Close stops and releases the watcher, the callback function will not be called any more. |
| UpdateForAddPolicy(sec, ptype string, params ...string) error | UpdateForAddPolicy calls the update callback of other instances to synchronize their policy. It is called after a policy is added via Enforcer.AddPolicy(), Enforcer.AddNamedPolicy(), Enforcer.AddGroupingPolicy() and Enforcer.AddNamedGroupingPolicy(). |
| UpdateForRemovePolicy(sec, ptype string, params ...string) error | UPdateForRemovePolicy calls the update callback of other instances to synchronize their policy. It is called after a policy is removed by Enforcer.RemovePolicy(), Enforcer.RemoveNamedPolicy(), Enforcer.RemoveGroupingPolicy() and Enforcer.RemoveNamedGroupingPolicy(). |
| 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.RemoveFilteredPolicy(), Enforcer.RemoveFilteredNamedPolicy(), Enforcer.RemoveFilteredGroupingPolicy() and Enforcer.RemoveFilteredNamedGroupingPolicy(). |
| UpdateForSavePolicy(model model.Model) error | UpdateForSavePolicy calls the update callback of other instances to synchronize their policy. It is called after Enforcer.SavePolicy() |
| 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(), Enforcer.AddNamedPolicies(), Enforcer.AddGroupingPolicies() and Enforcer.AddNamedGroupingPolicies(). |
| 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(), Enforcer.RemoveNamedPolicies(), Enforcer.RemoveGroupingPolicies() and Enforcer.RemoveNamedGroupingPolicies(). |