Add RELEASE note about config versioning
Closes
@@ -173,6 +173,7 @@ containerd versions:
| GRPC API | Stable | 1.0 | [api/](api) |
| Metrics API | Stable | 1.0 | - |
| Runtime Shim API | Stable | 1.2 | - |
+| Daemon Config | Stable | 1.0 | - |
| Go client API | Unstable | _future_ | [godoc](https://godoc.org/github.com/containerd/containerd) |
| CRI GRPC API | Unstable | v1alpha2 _current_ | [api/](https://github.com/kubernetes/kubernetes/tree/master/pkg/kubelet/apis/cri/runtime/v1alpha2) |
| `ctr` tool | Unstable | Out of scope | - |
@@ -271,6 +272,13 @@ may be completely refactored or have breaking changes in _minor_ releases.
We will try not break the tool in _patch_ releases.
+### Daemon Configuration
+
+The daemon's configuration file, commonly located in `/etc/containerd/config.toml`
+is versioned and backwards compatible. The `version = 2` field in the config
+file specifies the config's version. If no version number is specified inside
+the config file then it is assumed to be a version 1 config and parsed as such.
+
### Not Covered
As a general rule, anything not mentioned in this document is not covered by
