Move namers under cmdutils

These are only meant for interactive use in commands, not the API.
So cmdutils is the best place to keep these.

integration/creategetdelete_test.go

@@ -14,14 +14,14 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 
 	api "github.com/weaveworks/eksctl/pkg/apis/eksctl.io/v1alpha4"
+	"github.com/weaveworks/eksctl/pkg/ctl/cmdutils"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 	"github.com/onsi/gomega/gexec"
 
 	"github.com/weaveworks/eksctl/pkg/testutils/aws"
 	. "github.com/weaveworks/eksctl/pkg/testutils/matchers"
-	"github.com/weaveworks/eksctl/pkg/utils"
 )
 
 var _ = Describe("(Integration) Create, Get, Scale & Delete", func() {
@@ -60,7 +60,7 @@ var _ = Describe("(Integration) Create, Get, Scale & Delete", func() {
 			fmt.Fprintf(GinkgoWriter, "Using kubeconfig: %s\n", kubeconfigPath)
 
 			if clusterName == "" {
-				clusterName = utils.ClusterName("", "")
+				clusterName = cmdutils.ClusterName("", "")
 			}
 
 			eksctl("create", "cluster",

pkg/ctl/cmdutils/namers.go

@@ -0,0 +1,57 @@
+package cmdutils
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+
+	"github.com/kubicorn/kubicorn/pkg/namer"
+)
+
+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 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))
+	})
+}
+
+// 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 ""
+	}
+	if a != "" {
+		return a
+	}
+	if b != "" {
+		return b
+	}
+	return generate()
+}
+
+// ClusterName 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.
+func ClusterName(a, b string) string {
+	return useNameOrGenerate(a, b, func() string {
+		return fmt.Sprintf("%s-%d", namer.RandomName(), time.Now().Unix())
+	})
+}

pkg/ctl/create/nodegroup_utils.go

@@ -2,39 +2,13 @@ package create
 
 import (
 	"fmt"
-	"math/rand"
-	"time"
 
 	"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/ctl/cmdutils"
-	"github.com/weaveworks/eksctl/pkg/utils"
 )
 
-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 *cmdutils.NodeGroupFilter, nodeGroups []*api.NodeGroup, cmd *cobra.Command) error {
 	return ngFilter.CheckEachNodeGroup(nodeGroups, func(i int, ng *api.NodeGroup) error {
 		if ng.AllowSSH && ng.SSHPublicKeyPath == "" {