diff --git a/pkg/ctl/create/cluster.go b/pkg/ctl/create/cluster.go
index 5620aaf732..c9e90ec96a 100644
--- a/pkg/ctl/create/cluster.go
+++ b/pkg/ctl/create/cluster.go
@@ -59,7 +59,7 @@ func createClusterCmd(g *cmdutils.Grouping) *cobra.Command {
 	group := g.New(cmd)
 
 	exampleClusterName := utils.ClusterName("", "")
-	exampleNodeGroupName := utils.NodeGroupName("", "")
+	exampleNodeGroupName := NodeGroupName("", "")
 
 	group.InFlagSet("General", func(fs *pflag.FlagSet) {
 		fs.StringVarP(&cfg.Metadata.Name, "name", "n", "", fmt.Sprintf("EKS cluster name (generated if unspecified, e.g. %q)", exampleClusterName))
@@ -176,7 +176,7 @@ func doCreateCluster(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg stri
 
 		skipNodeGroupsIfRequested(cfg)
 
-		if err := CheckEachNodeGroup(ngFilter, cfg, NewNodeGroupChecker); err != nil {
+		if err := setNodeGroupDefaults(ngFilter, cfg.NodeGroups); err != nil {
 			return err
 		}
 	} else {
@@ -194,17 +194,7 @@ func doCreateCluster(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg stri
 
 		skipNodeGroupsIfRequested(cfg)
 
-		err := CheckEachNodeGroup(ngFilter, cfg, func(i int, ng *api.NodeGroup) error {
-			if ng.AllowSSH && ng.SSHPublicKeyPath == "" {
-				return fmt.Errorf("--ssh-public-key must be non-empty string")
-			}
-
-			// generate nodegroup name or use flag
-			ng.Name = utils.NodeGroupName(ng.Name, "")
-
-			return nil
-		})
-		if err != nil {
+		if err := configureNodeGroups(ngFilter, cfg.NodeGroups, cmd); err != nil {
 			return err
 		}
 	}
@@ -305,7 +295,7 @@ func doCreateCluster(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg stri
 				return err
 			}
 
-			if err := CheckEachNodeGroup(ngFilter, cfg, canUseForPrivateNodeGroups); err != nil {
+			if err := checkEachNodeGroup(ngFilter, cfg.NodeGroups, canUseForPrivateNodeGroups); err != nil {
 				return err
 			}
 
@@ -332,7 +322,7 @@ func doCreateCluster(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg stri
 			return err
 		}
 
-		if err := CheckEachNodeGroup(ngFilter, cfg, canUseForPrivateNodeGroups); err != nil {
+		if err := checkEachNodeGroup(ngFilter, cfg.NodeGroups, canUseForPrivateNodeGroups); err != nil {
 			return err
 		}
 
@@ -345,7 +335,7 @@ func doCreateCluster(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg stri
 		return err
 	}
 
-	err := CheckEachNodeGroup(ngFilter, cfg, func(_ int, ng *api.NodeGroup) error {
+	err := checkEachNodeGroup(ngFilter, cfg.NodeGroups, func(_ int, ng *api.NodeGroup) error {
 		// resolve AMI
 		if err := ctl.EnsureAMI(meta.Version, ng); err != nil {
 			return err
@@ -434,7 +424,7 @@ func doCreateCluster(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg stri
 			return err
 		}
 
-		err = CheckEachNodeGroup(ngFilter, cfg, func(_ int, ng *api.NodeGroup) error {
+		err = checkEachNodeGroup(ngFilter, cfg.NodeGroups, func(_ int, ng *api.NodeGroup) error {
 			// authorise nodes to join
 			if err = authconfigmap.AddNodeGroup(clientSet, ng); err != nil {
 				return err
diff --git a/pkg/ctl/create/nodegroup.go b/pkg/ctl/create/nodegroup.go
index 4b5b0af34c..56cf9f8641 100644
--- a/pkg/ctl/create/nodegroup.go
+++ b/pkg/ctl/create/nodegroup.go
@@ -43,7 +43,7 @@ func createNodeGroupCmd(g *cmdutils.Grouping) *cobra.Command {
 
 	group := g.New(cmd)
 
-	exampleNodeGroupName := utils.NodeGroupName("", "")
+	exampleNodeGroupName := NodeGroupName("", "")
 
 	group.InFlagSet("General", func(fs *pflag.FlagSet) {
 		fs.StringVar(&cfg.Metadata.Name, "cluster", "", "name of the EKS cluster to add the nodegroup to")
@@ -135,7 +135,7 @@ func doCreateNodeGroups(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg s
 			return err
 		}
 
-		if err := CheckEachNodeGroup(ngFilter, cfg, NewNodeGroupChecker); err != nil {
+		if err := checkEachNodeGroup(ngFilter, cfg.NodeGroups, NewNodeGroupChecker); err != nil {
 			return err
 		}
 	} else {
@@ -153,22 +153,10 @@ func doCreateNodeGroups(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg s
 			if cmd.Flag(f).Changed {
 				return fmt.Errorf("cannot use --%s unless a config file is specified via --config-file/-f", f)
 			}
+			return nil
 		}
 
-		err := CheckEachNodeGroup(ngFilter, cfg, func(i int, ng *api.NodeGroup) error {
-			if ng.AllowSSH && ng.SSHPublicKeyPath == "" {
-				return fmt.Errorf("--ssh-public-key must be non-empty string")
-			}
-
-			// generate nodegroup name or use either flag or argument
-			if utils.NodeGroupName(ng.Name, nameArg) == "" {
-				return cmdutils.ErrNameFlagAndArg(ng.Name, nameArg)
-			}
-			ng.Name = utils.NodeGroupName(ng.Name, nameArg)
-
-			return nil
-		})
-		if err != nil {
+		if err := configureNodeGroups(ngFilter, cfg.NodeGroups, cmd); err != nil {
 			return err
 		}
 
@@ -203,7 +191,7 @@ func doCreateNodeGroups(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg s
 		return err
 	}
 
-	err := CheckEachNodeGroup(ngFilter, cfg, func(_ int, ng *api.NodeGroup) error {
+	err := checkEachNodeGroup(ngFilter, cfg.NodeGroups, func(_ int, ng *api.NodeGroup) error {
 		// resolve AMI
 		if err := ctl.EnsureAMI(meta.Version, ng); err != nil {
 			return err
@@ -263,7 +251,7 @@ func doCreateNodeGroups(p *api.ProviderConfig, cfg *api.ClusterConfig, nameArg s
 			return err
 		}
 
-		err = CheckEachNodeGroup(ngFilter, cfg, func(_ int, ng *api.NodeGroup) error {
+		err = checkEachNodeGroup(ngFilter, cfg.NodeGroups, func(_ int, ng *api.NodeGroup) error {
 			if updateAuthConfigMap {
 				// authorise nodes to join
 				if err = authconfigmap.AddNodeGroup(clientSet, ng); err != nil {
diff --git a/pkg/ctl/create/nodegroup_utils.go b/pkg/ctl/create/nodegroup_utils.go
new file mode 100644
index 0000000000..721fc20ac6
--- /dev/null
+++ b/pkg/ctl/create/nodegroup_utils.go
@@ -0,0 +1,126 @@
+package create
+
+import (
+	"fmt"
+	"github.com/spf13/cobra"
+	"github.com/weaveworks/eksctl/pkg/ami"
+	api "github.com/weaveworks/eksctl/pkg/apis/eksctl.io/v1alpha4"
+	"github.com/weaveworks/eksctl/pkg/utils"
+	"math/rand"
+	"time"
+)
+
+const (
+	randNodeGroupNameLength     = 8
+	randNodeGroupNameComponents = "abcdef0123456789"
+)
+
+var r = rand.New(rand.NewSource(time.Now().UnixNano()))
+
+// NodeGroupName generates a name string when a and b are empty strings.
+// If either a or b are non-empty, it returns whichever is non-empty.
+// If neither a nor b are empty, it returns empty name, to indicate
+// ambiguous usage.
+// It uses a different naming scheme from ClusterName, so that users can
+// easily distinguish a cluster name from nodegroup name.
+func NodeGroupName(a, b string) string {
+	return utils.UseNameOrGenerate(a, b, func() string {
+		name := make([]byte, randNodeGroupNameLength)
+		for i := 0; i < randNodeGroupNameLength; i++ {
+			name[i] = randNodeGroupNameComponents[r.Intn(len(randNodeGroupNameComponents))]
+		}
+		return fmt.Sprintf("ng-%s", string(name))
+	})
+}
+
+func configureNodeGroups(ngFilter *NodeGroupFilter, nodeGroups []*api.NodeGroup, cmd *cobra.Command) error {
+	return checkEachNodeGroup(ngFilter, nodeGroups, func(i int, ng *api.NodeGroup) error {
+		if ng.AllowSSH && ng.SSHPublicKeyPath == "" {
+			return fmt.Errorf("--ssh-public-key must be non-empty string")
+		}
+
+		if cmd.Flag("ssh-public-key").Changed {
+			ng.AllowSSH = true
+		}
+
+		// generate nodegroup name or use flag
+		ng.Name = NodeGroupName(ng.Name, "")
+
+		return nil
+	})
+}
+
+func setNodeGroupDefaults(ngFilter *NodeGroupFilter, nodeGroups []*api.NodeGroup) error {
+	return checkEachNodeGroup(ngFilter, nodeGroups, func(i int, ng *api.NodeGroup) error {
+
+		if err := api.ValidateNodeGroup(i, ng); err != nil {
+			return err
+		}
+
+		// apply defaults
+		if ng.InstanceType == "" {
+			ng.InstanceType = api.DefaultNodeType
+		}
+		if ng.AMIFamily == "" {
+			ng.AMIFamily = ami.ImageFamilyAmazonLinux2
+		}
+		if ng.AMI == "" {
+			ng.AMI = ami.ResolverStatic
+		}
+
+		if ng.SecurityGroups == nil {
+			ng.SecurityGroups = &api.NodeGroupSGs{
+				AttachIDs: []string{},
+			}
+		}
+		if ng.SecurityGroups.WithLocal == nil {
+			ng.SecurityGroups.WithLocal = api.NewBoolTrue()
+		}
+		if ng.SecurityGroups.WithShared == nil {
+			ng.SecurityGroups.WithShared = api.NewBoolTrue()
+		}
+
+		// Enable SSH when a key is provided
+		if ng.SSHPublicKeyPath != "" {
+			ng.AllowSSH = true
+		}
+
+		if ng.AllowSSH && ng.SSHPublicKeyPath == "" {
+			ng.SSHPublicKeyPath = defaultSSHPublicKey
+		}
+
+		if ng.VolumeSize > 0 {
+			if ng.VolumeType == "" {
+				ng.VolumeType = api.DefaultNodeVolumeType
+			}
+		}
+
+		if ng.IAM == nil {
+			ng.IAM = &api.NodeGroupIAM{}
+		}
+		if ng.IAM.WithAddonPolicies.ImageBuilder == nil {
+			ng.IAM.WithAddonPolicies.ImageBuilder = api.NewBoolFalse()
+		}
+		if ng.IAM.WithAddonPolicies.AutoScaler == nil {
+			ng.IAM.WithAddonPolicies.AutoScaler = api.NewBoolFalse()
+		}
+		if ng.IAM.WithAddonPolicies.ExternalDNS == nil {
+			ng.IAM.WithAddonPolicies.ExternalDNS = api.NewBoolFalse()
+		}
+
+		return nil
+	})
+}
+
+// CheckEachNodeGroup iterates over each nodegroup and calls check function
+// (this is needed to avoid common goroutine-for-loop pitfall)
+func checkEachNodeGroup(ngFilter *NodeGroupFilter, nodeGroups []*api.NodeGroup, check func(i int, ng *api.NodeGroup) error) error {
+	for i, ng := range nodeGroups {
+		if ngFilter.Match(ng) {
+			if err := check(i, ng); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
diff --git a/pkg/ctl/create/utils_test.go b/pkg/ctl/create/nodegroup_utils_test.go
similarity index 93%
rename from pkg/ctl/create/utils_test.go
rename to pkg/ctl/create/nodegroup_utils_test.go
index d9c22570ad..e562df985d 100644
--- a/pkg/ctl/create/utils_test.go
+++ b/pkg/ctl/create/nodegroup_utils_test.go
@@ -1,4 +1,4 @@
-package create_test
+package create
 
 import (
 	"bytes"
@@ -7,7 +7,6 @@ import (
 	. "github.com/onsi/gomega"
 
 	api "github.com/weaveworks/eksctl/pkg/apis/eksctl.io/v1alpha4"
-	. "github.com/weaveworks/eksctl/pkg/ctl/create"
 	"github.com/weaveworks/eksctl/pkg/printers"
 )
 
@@ -274,7 +273,7 @@ var _ = Describe("create utils", func() {
 			f := NewNodeGroupFilter()
 
 			names := []string{}
-			CheckEachNodeGroup(f, cfg, func(i int, nodeGroup *api.NodeGroup) error {
+			checkEachNodeGroup(f, cfg.NodeGroups, func(i int, nodeGroup *api.NodeGroup) error {
 				Expect(nodeGroup).To(Equal(cfg.NodeGroups[i]))
 				names = append(names, nodeGroup.Name)
 				return nil
@@ -285,7 +284,7 @@ var _ = Describe("create utils", func() {
 			cfg.NodeGroups[0].Name = "ng-x0"
 			cfg.NodeGroups[1].Name = "ng-x1"
 			cfg.NodeGroups[2].Name = "ng-x2"
-			CheckEachNodeGroup(f, cfg, func(i int, nodeGroup *api.NodeGroup) error {
+			checkEachNodeGroup(f, cfg.NodeGroups, func(i int, nodeGroup *api.NodeGroup) error {
 				Expect(nodeGroup).To(Equal(cfg.NodeGroups[i]))
 				names = append(names, nodeGroup.Name)
 				return nil
@@ -300,7 +299,7 @@ var _ = Describe("create utils", func() {
 			f := NewNodeGroupFilter()
 
 			names := []string{}
-			CheckEachNodeGroup(f, cfg, func(i int, nodeGroup *api.NodeGroup) error {
+			checkEachNodeGroup(f, cfg.NodeGroups, func(i int, nodeGroup *api.NodeGroup) error {
 				Expect(nodeGroup).To(Equal(cfg.NodeGroups[i]))
 				names = append(names, nodeGroup.Name)
 				return nil
@@ -315,7 +314,7 @@ var _ = Describe("create utils", func() {
 
 			err = f.ApplyOnlyFilter([]string{"test-ng1?", "te*-ng3?"}, cfg)
 			Expect(err).ToNot(HaveOccurred())
-			CheckEachNodeGroup(f, cfg, func(i int, nodeGroup *api.NodeGroup) error {
+			checkEachNodeGroup(f, cfg.NodeGroups, func(i int, nodeGroup *api.NodeGroup) error {
 				Expect(nodeGroup).To(Equal(cfg.NodeGroups[i]))
 				names = append(names, nodeGroup.Name)
 				return nil
@@ -332,9 +331,9 @@ var _ = Describe("create utils", func() {
 			printer := printers.NewJSONPrinter()
 
 			names := []string{}
-			CheckEachNodeGroup(f, cfg, NewNodeGroupChecker)
+			checkEachNodeGroup(f, cfg.NodeGroups, NewNodeGroupChecker)
 
-			CheckEachNodeGroup(f, cfg, func(i int, nodeGroup *api.NodeGroup) error {
+			checkEachNodeGroup(f, cfg.NodeGroups, func(i int, nodeGroup *api.NodeGroup) error {
 				Expect(nodeGroup).To(Equal(cfg.NodeGroups[i]))
 				names = append(names, nodeGroup.Name)
 				return nil
diff --git a/pkg/ctl/create/utils.go b/pkg/ctl/create/utils.go
index ddecb0548b..a951400249 100644
--- a/pkg/ctl/create/utils.go
+++ b/pkg/ctl/create/utils.go
@@ -123,19 +123,6 @@ func (f *NodeGroupFilter) LogInfo(cfg *api.ClusterConfig) {
 	}
 }
 
-// CheckEachNodeGroup iterates over each nodegroup and calls check function
-// (this is needed to avoid common goroutine-for-loop pitfall)
-func CheckEachNodeGroup(f *NodeGroupFilter, cfg *api.ClusterConfig, check func(i int, ng *api.NodeGroup) error) error {
-	for i, ng := range cfg.NodeGroups {
-		if f.Match(ng) {
-			if err := check(i, ng); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
 // NewNodeGroupChecker validates a new nodegroup and applies defaults
 func NewNodeGroupChecker(i int, ng *api.NodeGroup) error {
 	if err := api.ValidateNodeGroup(i, ng); err != nil {
diff --git a/pkg/utils/namer.go b/pkg/utils/namer.go
index e5940d9086..fa0201a7df 100644
--- a/pkg/utils/namer.go
+++ b/pkg/utils/namer.go
@@ -2,13 +2,14 @@ package utils
 
 import (
 	"fmt"
-	"math/rand"
 	"time"
 
 	"github.com/kubicorn/kubicorn/pkg/namer"
 )
 
-func useNameOrGenerate(a, b string, generate func() string) string {
+// UseNameOrGenerate picks one of the provided strings or generates a
+// new one using the provided generate function
+func UseNameOrGenerate(a, b string, generate func() string) string {
 	if a != "" && b != "" {
 		return ""
 	}
@@ -26,30 +27,7 @@ func useNameOrGenerate(a, b string, generate func() string) string {
 // If neither a nor b are empty, it returns empty name, to indicate
 // ambiguous usage.
 func ClusterName(a, b string) string {
-	return useNameOrGenerate(a, b, func() string {
+	return UseNameOrGenerate(a, b, func() string {
 		return fmt.Sprintf("%s-%d", namer.RandomName(), time.Now().Unix())
 	})
 }
-
-var r = rand.New(rand.NewSource(time.Now().UnixNano()))
-
-const (
-	randNodeGroupNameLength     = 8
-	randNodeGroupNameComponents = "abcdef0123456789"
-)
-
-// NodeGroupName generates a name string when a and b are empty strings.
-// If either a or b are non-empty, it returns whichever is non-empty.
-// If neither a nor b are empty, it returns empty name, to indicate
-// ambiguous usage.
-// It uses a different naming scheme from ClusterName, so that users can
-// easily distinguish a cluster name from nodegroup name.
-func NodeGroupName(a, b string) string {
-	return useNameOrGenerate(a, b, func() string {
-		name := make([]byte, randNodeGroupNameLength)
-		for i := 0; i < randNodeGroupNameLength; i++ {
-			name[i] = randNodeGroupNameComponents[r.Intn(len(randNodeGroupNameComponents))]
-		}
-		return fmt.Sprintf("ng-%s", string(name))
-	})
-}