vendor/github.com/hashicorp/terraform/terraform/transform_root.go

   1 package terraform
   2
   3 import "github.com/hashicorp/terraform/dag"
   4
   5 const rootNodeName = "root"
   6
   7 // RootTransformer is a GraphTransformer that adds a root to the graph.
   8 type RootTransformer struct{}
   9
  10 func (t *RootTransformer) Transform(g *Graph) error {
  11         // If we already have a good root, we're done
  12         if _, err := g.Root(); err == nil {
  13                 return nil
  14         }
  15
  16         // Add a root
  17         var root graphNodeRoot
  18         g.Add(root)
  19
  20         // Connect the root to all the edges that need it
  21         for _, v := range g.Vertices() {
  22                 if v == root {
  23                         continue
  24                 }
  25
  26                 if g.UpEdges(v).Len() == 0 {
  27                         g.Connect(dag.BasicEdge(root, v))
  28                 }
  29         }
  30
  31         return nil
  32 }
  33
  34 type graphNodeRoot struct{}
  35
  36 func (n graphNodeRoot) Name() string {
  37         return rootNodeName
  38 }