kubernetes/client-go
Client Go
This project is a Go language library that provides a programmatic interface for interacting with the Kubernetes API server. It serves as a client for managing cluster resources, offering both typed interfaces for compile-time safety and dynamic interfaces for unstructured data and custom resource management.
The library includes a controller framework designed for building event-driven automation. This framework utilizes informers to maintain local resource caches and rate-limited work queues to decouple event detection from state reconciliation. High availability is supported through a leader election tool that uses shared lease objects to ensure single-writer exclusivity.
Beyond core API interaction, the project covers secure authentication via internal service tokens and pluggable external credential providers. It also provides utilities for server-side apply functionality, API capability discovery, and tools for mocking API responses during testing.
Features
- Kubernetes API Clients - Provides the primary Go library for interacting with Kubernetes control planes via secure API clients.
- Kubernetes Controllers - Provides a framework for building event-driven controllers that synchronize cluster state via reconciliation loops.
- Event Distribution Caches - Distributes resource change events to multiple handlers via a centralized cache to reduce API server load.
- Resource Mirrors - Maintains a local mirrored state of server resources by combining initial snapshots with continuous watch streams.
- Informer Synchronization - Combines initial snapshots with a continuous stream of changes to maintain a local cache of resources.
- Custom Resource Definitions - Defines custom resource types and implements controllers to manage application-specific state.
- Kubernetes Operations Automation - Enables programmatic management of cluster resources to automate infrastructure and application lifecycles.
- Local Resource Caches - Mirrors server-side resources into local memory to enable high-performance cluster state queries.
- Cluster State Caching - Caches cluster objects locally to provide fast synchronization mechanisms for building efficient controllers.
- Reconciliation Queues - Decouples event detection from reconciliation using object queues with retry logic and throughput throttling.
- Type-Safe API Clients - Executes requests against the server using a typed clientset for compile-time safety.
- Unstructured API Clients - Accesses arbitrary API resources without compile-time types by using generic maps to represent server objects.
- Distributed Leader Election - Coordinates high availability using distributed locks on shared objects to ensure single-writer exclusivity.
- Leader Election - Provides leader election tools using shared lease objects to ensure high availability and prevent concurrent writes.
- Coordination Tools - Implements coordination mechanisms using shared lease objects to ensure only one active process performs work.
- Remote Cluster Access - Enables authentication and communication with clusters from environments outside the cluster.
- Server-Side Apply Operations - Constructs declarative patches using type-safe builders for collaborative object management.
- Reconciliation Queues - Implements rate-limited work queues to decouple resource event detection from state reconciliation.
- Authentication Providers - Resolves identity tokens through a registry of external plugins to support diverse credential sources.
- Externalized Credential Loaders - Extracts authentication tokens from external providers to gain authorized access to the server.
- External Identity Provider Integration - Verifies user identities through external credential sources using plugins to secure connections.
- Developer Workspaces - Official Go client library for Kubernetes.
