| name | config-center |
| description | ConfigCenter subsystem — ConfCenter trait abstraction, FileSystemCenter and KubernetesCenter implementations, unified Workqueue + ResourceProcessor pipeline. |
03 ConfigCenter
The ConfigCenter is a core Controller subsystem responsible for receiving resource configuration from various sources.
Both backends share the same Workqueue + ResourceProcessor pipeline; only the event source and persistence layer differ.
ConfCenter Trait Abstraction
The ConfigCenter defines a unified interface via the ConfCenter trait, which contains two groups of capabilities:
- CenterApi — resource CRUD operations:
get_one, set_one, create_one, update_one, list
- CenterLifeCycle — lifecycle management:
start, ready check, reload, shutdown
Whether the underlying backend is the file system or the Kubernetes API, the upper-layer Workqueue and ResourceProcessor pipeline is identical. Resource changes from the event source enter the Workqueue uniformly for dedup and delayed (coalesced) requeue, then the ResourceProcessor performs validation, preparse, processing, and dispatch.
File List
| File | Topic | Recommended reading scenario |
|---|
| 00-overview.md | ConfCenter trait architecture | Understanding the ConfigCenter abstraction design |
| 01-file-system.md | FileSystemCenter implementation | Local development / debugging mode |
| 02-kubernetes/ | Kubernetes ConfigCenter | Production environments, HA, leader election |
| (etcd has no standalone document) | EtcdCenter implementation | Non-K8s production, single-Controller deployment |
Architecture Comparison
ConfCenter trait
├── CenterApi (CRUD: get_one, set_one, create_one, update_one, list)
└── CenterLifeCycle (start, ready check, reload, shutdown)
FileSystemCenter KubernetesCenter EtcdCenter
├── Local YAML files ├── K8s API Server ├── etcd KV store
├── inotify watching ├── Reflector watch ├── etcd watch events
├── .status files ├── Status subresource ├── No status persistence
├── No leader elect ├── Lease-based election ├── No leader election
└── Use: dev/test └── Use: production K8s └── Use: non-K8s production
EtcdCenter design constraint: EtcdStorage::create_one/update_one are non-atomic check-then-write operations. The design assumes a single Controller exclusively owns etcd; concurrent writes from multiple Controllers to the same etcd instance are not supported.
