*: update drainExecSyncIO docs and validate the timeout

We should validate the drainExecSyncIO timeout at the beginning and
raise the error for any invalid input.

Signed-off-by: Wei Fu <fuweid89@gmail.com>
(cherry picked from commit 791f137)
Signed-off-by: Wei Fu <fuweid89@gmail.com>

docs/cri/config.md

@@ -120,6 +120,16 @@ version = 2
   # Note that currently default is set to disabled but target change it in future together with enable_unprivileged_ports
   enable_unprivileged_icmp = false
 
+  # drain_exec_sync_io_timeout is the maximum duration to wait for ExecSync API'
+  # IO EOF event after exec init process exits. A zero value means there is no
+  # timeout.
+  #
+  # The string is in the golang duration format, see:
+  #    https://golang.org/pkg/time/#ParseDuration
+  #
+  # For example, the value can be '5h', '2h30m', '10s'.
+  drain_exec_sync_io_timeout = "0s"
+
   # 'plugins."io.containerd.grpc.v1.cri".containerd' contains config related to containerd
   [plugins."io.containerd.grpc.v1.cri".containerd]
 

pkg/cri/config/config.go

@@ -312,6 +312,8 @@ type PluginConfig struct {
 	//
 	// The string is in the golang duration format, see:
 	//   https://golang.org/pkg/time/#ParseDuration
+	//
+	// For example, the value can be '5h', '2h30m', '10s'.
 	DrainExecSyncIOTimeout string `toml:"drain_exec_sync_io_timeout" json:"drainExecSyncIOTimeout"`
 }
 

pkg/cri/config/config_unix.go

@@ -104,6 +104,6 @@ func DefaultConfig() PluginConfig {
 		ImageDecryption: ImageDecryption{
 			KeyModel: KeyModelNode,
 		},
-		DrainExecSyncIOTimeout: "0",
+		DrainExecSyncIOTimeout: "0s",
 	}
 }

pkg/cri/config/config_windows.go

@@ -62,6 +62,6 @@ func DefaultConfig() PluginConfig {
 		ImageDecryption: ImageDecryption{
 			KeyModel: KeyModelNode,
 		},
-		DrainExecSyncIOTimeout: "0",
+		DrainExecSyncIOTimeout: "0s",
 	}
 }