plugins/drivers: nil gaurd driver config when building executor config

plugins/drivers/utils/utils.go

@@ -17,6 +17,16 @@ import (
 	"github.com/hashicorp/nomad/plugins/base"
 )
 
+const (
+	// ExecutorDefaultMaxPort is the default max port used by the executor for
+	// searching for an available port
+	ExecutorDefaultMaxPort = 14512
+
+	// ExecutorDefaultMinPort is the default min port used by the executor for
+	// searching for an available port
+	ExecutorDefaultMinPort = 14000
+)
+
 // CgroupsMounted returns true if the cgroups are mounted on a system otherwise
 // returns false
 func CgroupsMounted(node *structs.Node) bool {
@@ -26,7 +36,7 @@ func CgroupsMounted(node *structs.Node) bool {
 
 // CreateExecutor launches an executor plugin and returns an instance of the
 // Executor interface
-func CreateExecutor(w io.Writer, level hclog.Level, nomadConfig *base.ClientDriverConfig,
+func CreateExecutor(w io.Writer, level hclog.Level, driverConfig *base.ClientDriverConfig,
 	executorConfig *dstructs.ExecutorConfig) (executor.Executor, *plugin.Client, error) {
 
 	c, err := json.Marshal(executorConfig)
@@ -44,8 +54,13 @@ func CreateExecutor(w io.Writer, level hclog.Level, nomadConfig *base.ClientDriv
 	config.HandshakeConfig = driver.HandshakeConfig
 	config.Plugins = driver.GetPluginMap(w, level, executorConfig.FSIsolation)
 
-	config.MaxPort = nomadConfig.ClientMaxPort
-	config.MinPort = nomadConfig.ClientMinPort
+	if driverConfig != nil {
+		config.MaxPort = driverConfig.ClientMaxPort
+		config.MinPort = driverConfig.ClientMinPort
+	} else {
+		config.MaxPort = ExecutorDefaultMaxPort
+		config.MinPort = ExecutorDefaultMinPort
+	}
 
 	// setting the setsid of the plugin process so that it doesn't get signals sent to
 	// the nomad client.