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

   1 package terraform
   2
   3 import (
   4         "log"
   5 )
   6
   7 // EvalCountFixZeroOneBoundaryGlobal is an EvalNode that fixes up the state
   8 // when there is a resource count with zero/one boundary, i.e. fixing
   9 // a resource named "aws_instance.foo" to "aws_instance.foo.0" and vice-versa.
  10 //
  11 // This works on the global state.
  12 type EvalCountFixZeroOneBoundaryGlobal struct{}
  13
  14 // TODO: test
  15 func (n *EvalCountFixZeroOneBoundaryGlobal) Eval(ctx EvalContext) (interface{}, error) {
  16         // Get the state and lock it since we'll potentially modify it
  17         state, lock := ctx.State()
  18         lock.Lock()
  19         defer lock.Unlock()
  20
  21         // Prune the state since we require a clean state to work
  22         state.prune()
  23
  24         // Go through each modules since the boundaries are restricted to a
  25         // module scope.
  26         for _, m := range state.Modules {
  27                 if err := n.fixModule(m); err != nil {
  28                         return nil, err
  29                 }
  30         }
  31
  32         return nil, nil
  33 }
  34
  35 func (n *EvalCountFixZeroOneBoundaryGlobal) fixModule(m *ModuleState) error {
  36         // Counts keeps track of keys and their counts
  37         counts := make(map[string]int)
  38         for k, _ := range m.Resources {
  39                 // Parse the key
  40                 key, err := ParseResourceStateKey(k)
  41                 if err != nil {
  42                         return err
  43                 }
  44
  45                 // Set the index to -1 so that we can keep count
  46                 key.Index = -1
  47
  48                 // Increment
  49                 counts[key.String()]++
  50         }
  51
  52         // Go through the counts and do the fixup for each resource
  53         for raw, count := range counts {
  54                 // Search and replace this resource
  55                 search := raw
  56                 replace := raw + ".0"
  57                 if count < 2 {
  58                         search, replace = replace, search
  59                 }
  60                 log.Printf("[TRACE] EvalCountFixZeroOneBoundaryGlobal: count %d, search %q, replace %q", count, search, replace)
  61
  62                 // Look for the resource state. If we don't have one, then it is okay.
  63                 rs, ok := m.Resources[search]
  64                 if !ok {
  65                         continue
  66                 }
  67
  68                 // If the replacement key exists, we just keep both
  69                 if _, ok := m.Resources[replace]; ok {
  70                         continue
  71                 }
  72
  73                 m.Resources[replace] = rs
  74                 delete(m.Resources, search)
  75         }
  76
  77         return nil
  78 }