commands: add implementations for create, use, rm, stop

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

store/nodegroup.go

@@ -0,0 +1,109 @@
+package store
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+type NodeGroup struct {
+	Name   string
+	Driver string
+	Nodes  []Node
+}
+
+type Node struct {
+	Name      string
+	Endpoint  string
+	Platforms []string
+}
+
+func (ng *NodeGroup) Leave(name string) error {
+	i := ng.findNode(name)
+	if i == -1 {
+		return errors.Errorf("node %q not found for %s", name, ng.Name)
+	}
+	if len(ng.Nodes) == 1 {
+		return errors.Errorf("can not leave last node, do you want to rm instance instead?")
+	}
+	ng.Nodes = append(ng.Nodes[:i], ng.Nodes[i+1:]...)
+	return nil
+}
+
+func (ng *NodeGroup) Update(name, endpoint string, platforms []string, endpointsSet bool, actionAppend bool) error {
+	i := ng.findNode(name)
+	if i == -1 && !actionAppend {
+		ng.Nodes = nil
+	}
+	if i != -1 {
+		n := ng.Nodes[i]
+		if endpointsSet {
+			n.Endpoint = endpoint
+		}
+		if len(platforms) > 0 {
+			n.Platforms = platforms
+		}
+		ng.Nodes[i] = n
+		if err := ng.validateDuplicates(endpoint); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	if name == "" {
+		name = ng.nextNodeName()
+	}
+
+	name, err := ValidateName(name)
+	if err != nil {
+		return err
+	}
+
+	n := Node{
+		Name:      name,
+		Endpoint:  endpoint,
+		Platforms: platforms,
+	}
+	ng.Nodes = append(ng.Nodes, n)
+
+	if err := ng.validateDuplicates(endpoint); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (ng *NodeGroup) validateDuplicates(ep string) error {
+	// TODO: reset platforms
+	i := 0
+	for _, n := range ng.Nodes {
+		if n.Endpoint == ep {
+			i++
+		}
+	}
+	if i > 1 {
+		return errors.Errorf("invalid duplicate endpoint %s", ep)
+	}
+	return nil
+}
+
+func (ng *NodeGroup) findNode(name string) int {
+	i := -1
+	for ii, n := range ng.Nodes {
+		if n.Name == name {
+			i = ii
+		}
+	}
+	return i
+}
+
+func (ng *NodeGroup) nextNodeName() string {
+	i := 0
+	for {
+		name := fmt.Sprintf("%s%d", ng.Name, i)
+		if i := ng.findNode(name); i != -1 {
+			i++
+			continue
+		}
+		return name
+	}
+}