Shared Channel Service
Package sharedchannel implements Mattermost's shared channels functionality, for sharing channel content across Mattermost instances/clusters. Here are the key responsibilities:
Channel Sharing:
- Allows channels to be shared between different Mattermost instances/clusters
- Handles inviting remote clusters to shared channels
- Manages permissions and read-only status for shared channels
Content Synchronization:
- Syncs posts, reactions, user profiles, and file attachments between instances
- Handles permalink processing between instances
- Manages user profile images sync
- Maintains sync state and cursors to track what has been synchronized
Remote Communication:
- Processes incoming sync messages from remote clusters
- Sends updates to remote clusters when local changes occur
- Handles connection state changes with remote clusters
- Manages retry logic for failed sync attempts
Security:
- Validates permissions for shared channel operations
- Ensures users can only sync content they have access to
- Verifies remote cluster authenticity
- Sanitizes user data during sync
The service acts as a bridge between Mattermost instances, allowing users from different instances to collaborate in shared channels while keeping content synchronized across all participating instances.
This is implemented through a Service struct that handles all the shared channel operations and maintains the synchronization state. It works in conjunction with the RemoteCluster service to handle the actual communication between instances.