diff --git a/config.md b/config.md index 6862fe4f3..b4aef6a6d 100644 --- a/config.md +++ b/config.md @@ -442,8 +442,9 @@ The [state](runtime.md#state) of the container MUST be passed to hooks over stdi ### Prestart -The `prestart` hooks MUST be called after the [`start`](runtime.md#start) operation is called but [before the user-specified program command is executed](runtime.md#lifecycle). +The `prestart` hooks MUST be called as part of the [`create`](runtime.md#create) operation after the runtime environment has been created (according to the configuration in config.json) but before the `pivot_root` or any equivalent operation has been executed. On Linux, for example, they are called after the container namespaces are created, so they provide an opportunity to customize the container (e.g. the network namespace could be specified in this hook). +The `prestart` hooks MUST be called before the `createRuntime` hooks. Note: `prestart` hooks were deprecated in favor of `createRuntime`, `createContainer` and `startContainer` hooks, which allow more granular hook control during the create and start phase. @@ -461,8 +462,6 @@ On Linux, for example, they are called after the container namespaces are create The definition of `createRuntime` hooks is currently underspecified and hooks authors, should only expect from the runtime that the mount namespace have been created and the mount operations performed. Other operations such as cgroups and SELinux/AppArmor labels might not have been performed by the runtime. -Note: `runc` originally implemented `prestart` hooks contrary to the spec, namely as part of the `create` operation (instead of during the `start` operation). This incorrect implementation actually corresponds to `createRuntime` hooks. For runtimes that implement the deprecated `prestart` hooks as `createRuntime` hooks, `createRuntime` hooks MUST be called after the `prestart` hooks. - ### CreateContainer Hooks The `createContainer` hooks MUST be called as part of the [`create`](runtime.md#create) operation after the runtime environment has been created (according to the configuration in config.json) but before the `pivot_root` or any equivalent operation has been executed.