Merge pull request opencontainers#701 from wking/optional-process

config: Make process optional

Author: Michael Crosby

config.md

@@ -119,7 +119,8 @@ For Windows, see [mountvol][mountvol] and [SetVolumeMountPoint][set-volume-mount
 
 ## <a name="configProcess" />Process
 
-**`process`** (object, REQUIRED) specifies the container process.
+**`process`** (object, OPTIONAL) specifies the container process.
+  This property is REQUIRED when [`start`](runtime.md#start) is called.
 
 * **`terminal`** (bool, OPTIONAL) specifies whether a terminal is attached to that process, defaults to false.
   As an example, if set to true on Linux a pseudoterminal pair is allocated for the container process and the pseudoterminal slave is duplicated on the container process's [standard streams][stdin.3].

runtime.md

@@ -116,6 +116,7 @@ This operation MUST [generate an error](#errors) if it is not provided the conta
 Attempting to start a container that does not exist MUST [generate an error](#errors).
 Attempting to start an already started container MUST have no effect on the container and MUST [generate an error](#errors).
 This operation MUST run the user-specified program as specified by [`process`](config.md#process).
+This operation MUST generate an error if `process` was not set.
 
 ### <a name="runtimeKill" />Kill
 `kill <container-id> <signal>`

schema/config-schema.json

@@ -237,7 +237,6 @@
     "required": [
         "ociVersion",
         "platform",
-        "process",
         "root"
     ]
 }

specs-go/config.go

@@ -9,7 +9,7 @@ type Spec struct {
 	// Platform specifies the configuration's target platform.
 	Platform Platform `json:"platform"`
 	// Process configures the container process.
-	Process Process `json:"process"`
+	Process *Process `json:"process,omitempty"`
 	// Root configures the container's root filesystem.
 	Root Root `json:"root"`
 	// Hostname configures the container's hostname.