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

   1 package terraform
   2
   3 import (
   4         "fmt"
   5
   6         "github.com/hashicorp/terraform/config"
   7 )
   8
   9 // EvalValidateResourceSelfRef is an EvalNode implementation that validates that
  10 // a configuration doesn't contain a reference to the resource itself.
  11 //
  12 // This must be done prior to interpolating configuration in order to avoid
  13 // any infinite loop scenarios.
  14 type EvalValidateResourceSelfRef struct {
  15         Addr   **ResourceAddress
  16         Config **config.RawConfig
  17 }
  18
  19 func (n *EvalValidateResourceSelfRef) Eval(ctx EvalContext) (interface{}, error) {
  20         addr := *n.Addr
  21         conf := *n.Config
  22
  23         // Go through the variables and find self references
  24         var errs []error
  25         for k, raw := range conf.Variables {
  26                 rv, ok := raw.(*config.ResourceVariable)
  27                 if !ok {
  28                         continue
  29                 }
  30
  31                 // Build an address from the variable
  32                 varAddr := &ResourceAddress{
  33                         Path:         addr.Path,
  34                         Mode:         rv.Mode,
  35                         Type:         rv.Type,
  36                         Name:         rv.Name,
  37                         Index:        rv.Index,
  38                         InstanceType: TypePrimary,
  39                 }
  40
  41                 // If the variable access is a multi-access (*), then we just
  42                 // match the index so that we'll match our own addr if everything
  43                 // else matches.
  44                 if rv.Multi && rv.Index == -1 {
  45                         varAddr.Index = addr.Index
  46                 }
  47
  48                 // This is a weird thing where ResourceAddres has index "-1" when
  49                 // index isn't set at all. This means index "0" for resource access.
  50                 // So, if we have this scenario, just set our varAddr to -1 so it
  51                 // matches.
  52                 if addr.Index == -1 && varAddr.Index == 0 {
  53                         varAddr.Index = -1
  54                 }
  55
  56                 // If the addresses match, then this is a self reference
  57                 if varAddr.Equals(addr) && varAddr.Index == addr.Index {
  58                         errs = append(errs, fmt.Errorf(
  59                                 "%s: self reference not allowed: %q",
  60                                 addr, k))
  61                 }
  62         }
  63
  64         // If no errors, no errors!
  65         if len(errs) == 0 {
  66                 return nil, nil
  67         }
  68
  69         // Wrap the errors in the proper wrapper so we can handle validation
  70         // formatting properly upstream.
  71         return nil, &EvalValidateError{
  72                 Errors: errs,
  73         }
  74 }