starting to work on create

pkg/cfn/manager/nodegroup.go

@@ -44,6 +44,20 @@ func (c *StackCollection) CreateInitialNodeGroup(errs chan error) error {
 	return c.CreateNodeGroup(0, errs)
 }
 
+// CreateNextNodeGroup creates a node group with the next sequence number
+func (c *StackCollection) CreateNextNodeGroup(errs chan error) error {
+	currentSeq, err := c.GetMaxNodeGroupSeq()
+	if err != nil {
+		return errors.Wrap(err, "getting current node group sequence")
+	}
+	logger.Debug("max node group sequence: %d", currentSeq)
+
+	newSeq := currentSeq + 1
+	logger.Info("new node group sequence number: %d", newSeq)
+
+	return c.CreateNodeGroup(newSeq, errs)
+}
+
 // CreateNodeGroup creates the node group
 func (c *StackCollection) CreateNodeGroup(seq int, errs chan error) error {
 	name := c.makeNodeGroupStackName(seq)
@@ -130,6 +144,24 @@ func (c *StackCollection) ScaleNodeGroup(sequence int) error {
 	return c.UpdateStack(name, "scale-nodegroup", descriptionBuffer.String(), []byte(template), nil)
 }
 
+// GetMaxNodeGroupSeq returns the sequence number og the highest node group
+func (c *StackCollection) GetMaxNodeGroupSeq() (int, error) {
+	stacks, err := c.ListStacks(fmt.Sprintf("^(eksctl|EKS)-%s-nodegroup-\\d+$", c.spec.ClusterName))
+	if err != nil {
+		return -1, errors.Wrap(err, "getting nodegroup stacks")
+	}
+
+	seq := -1
+	for _, stack := range stacks {
+		stackSeq := getNodeGroupID(stack.Tags)
+		if stackSeq > seq {
+			seq = stackSeq
+		}
+	}
+
+	return seq, nil
+}
+
 // GetNodeGroupSummaries returns a list of summaries for the nodegroups of a cluster
 func (c *StackCollection) GetNodeGroupSummaries() ([]*NodeGroupSummary, error) {
 	stacks, err := c.ListStacks(fmt.Sprintf("^(eksctl|EKS)-%s-nodegroup-\\d+$", c.spec.ClusterName), cloudformation.StackStatusCreateComplete)
@@ -147,6 +179,7 @@ func (c *StackCollection) GetNodeGroupSummaries() ([]*NodeGroupSummary, error) {
 			return nil, errors.Wrapf(err, "error getting Cloudformation template for stack %s", *stack.StackName)
 		}
 
+		//TODO: create a map function
 		seq := getNodeGroupID(stack.Tags)
 		maxSize := gjson.Get(template, maxSizePath)
 		minSize := gjson.Get(template, minSizePath)

pkg/ctl/create/nodegroup.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/weaveworks/eksctl/pkg/cfn/manager"
+
 	"github.com/kubicorn/kubicorn/pkg/logger"
 	"github.com/spf13/cobra"
 	"github.com/weaveworks/eksctl/pkg/ctl"
@@ -71,6 +73,7 @@ func doAddNodeGroup(cfg *api.ClusterConfig, name string) error {
 
 	logger.Debug("cfg = %#v", cfg)
 
+	// Check the cluster exists and is active
 	eksCluster, err := ctl.DescribeControlPlane()
 	if err != nil {
 		return err
@@ -81,9 +84,17 @@ func doAddNodeGroup(cfg *api.ClusterConfig, name string) error {
 	logger.Info("found cluster %s", eksCluster.Name)
 	logger.Debug("cluster = %#v", eksCluster)
 
-	//TODO: get the next nodegroup sequnce number
+	errs := []error{}
+	appendErr := func(err error) {
+		errs = append(errs, err)
+	}
+
+	stackManager := ctl.NewStackManager()
+	if manager.Run(appendErr, stackManager.CreateNextNodeGroup); len(errs) > 0 {
+		//TODO: how to handle this????
+		//return errs
+	}
 
-	//TODO: finish
 	return nil
 
 }