Add kube-aws node-pools update command

cmd/nodepool/update.go

@@ -0,0 +1,69 @@
+package nodepool
+
+import (
+	"fmt"
+
+	"github.com/coreos/kube-aws/nodepool/cluster"
+	"github.com/coreos/kube-aws/nodepool/config"
+	"github.com/spf13/cobra"
+)
+
+var (
+	cmdUpdate = &cobra.Command{
+		Use:          "update",
+		Short:        "Update an existing node pool",
+		Long:         ``,
+		RunE:         runCmdUpdate,
+		SilenceUsage: true,
+	}
+
+	updateOpts = struct {
+		awsDebug bool
+		s3URI    string
+	}{}
+)
+
+func init() {
+	NodePoolCmd.AddCommand(cmdUpdate)
+	cmdUpdate.Flags().BoolVar(&updateOpts.awsDebug, "aws-debug", false, "Log debug information from aws-sdk-go library")
+	cmdUpdate.Flags().StringVar(&updateOpts.s3URI, "s3-uri", "", "When your template is bigger than the cloudformation limit of 51200 bytes, upload the template to the specified location in S3. S3 location expressed as s3://<bucket>/path/to/dir")
+}
+
+func runCmdUpdate(cmd *cobra.Command, args []string) error {
+	conf, err := config.ClusterFromFile(nodePoolClusterConfigFilePath())
+	if err != nil {
+		return fmt.Errorf("Failed to read node pool config: %v", err)
+	}
+
+	if err := conf.ValidateUserData(stackTemplateOptions()); err != nil {
+		return fmt.Errorf("Failed to validate user data: %v", err)
+	}
+
+	data, err := conf.RenderStackTemplate(stackTemplateOptions())
+	if err != nil {
+		return fmt.Errorf("Failed to render stack template: %v", err)
+	}
+
+	cluster := cluster.New(conf, updateOpts.awsDebug)
+
+	report, err := cluster.Update(string(data), updateOpts.s3URI)
+	if err != nil {
+		return fmt.Errorf("Error updating node pool: %v", err)
+	}
+	if report != "" {
+		fmt.Printf("Update stack: %s\n", report)
+	}
+
+	info, err := cluster.Info()
+	if err != nil {
+		return fmt.Errorf("Failed fetching node pool info: %v", err)
+	}
+
+	successMsg :=
+		`Success! Your AWS resources are being updated:
+%s
+`
+	fmt.Printf(successMsg, info.String())
+
+	return nil
+}

nodepool/cluster/cluster.go

@@ -58,6 +58,15 @@ func (c *Cluster) Create(stackBody string, s3URI string) error {
 	return c.stackProvisioner().CreateStackAndWait(cfSvc, s3Svc, stackBody, s3URI)
 }
 
+func (c *Cluster) Update(stackBody string, s3URI string) (string, error) {
+	cfSvc := cloudformation.New(c.session)
+	s3Svc := s3.New(c.session)
+
+	updateOutput, err := c.stackProvisioner().UpdateStackAndWait(cfSvc, s3Svc, stackBody, s3URI)
+
+	return updateOutput, err
+}
+
 func (c *Cluster) ValidateStack(stackBody string, s3URI string) (string, error) {
 	return c.stackProvisioner().Validate(stackBody, s3URI)
 }