Prevent user from deleting pre-defined networks

Signed-off-by: Madhu Venugopal <madhu@docker.com>
Upstream-commit: ead62b59522bba132b9a14712e4350439e7fa2a5
Component: engine

components/engine/runconfig/hostconfig_unix.go

@@ -66,6 +66,12 @@ func (n NetworkMode) IsUserDefined() bool {
 	return !n.IsDefault() && !n.IsBridge() && !n.IsHost() && !n.IsNone() && !n.IsContainer()
 }
 
+// IsPreDefinedNetwork indicates if a network is predefined by the daemon
+func IsPreDefinedNetwork(network string) bool {
+	n := NetworkMode(network)
+	return n.IsBridge() || n.IsHost() || n.IsNone()
+}
+
 //UserDefined indicates user-created network
 func (n NetworkMode) UserDefined() string {
 	if n.IsUserDefined() {

components/engine/runconfig/hostconfig_windows.go

@@ -27,3 +27,8 @@ func MergeConfigs(config *Config, hostConfig *HostConfig) *ContainerConfigWrappe
 		hostConfig,
 	}
 }
+
+// IsPreDefinedNetwork indicates if a network is predefined by the daemon
+func IsPreDefinedNetwork(network string) bool {
+	return false
+}