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

   1 package terraform
   2
   3 import (
   4         "fmt"
   5         "log"
   6         "strings"
   7
   8         "github.com/hashicorp/terraform/tfdiags"
   9
  10         "github.com/hashicorp/terraform/addrs"
  11 )
  12
  13 // GraphBuilder is an interface that can be implemented and used with
  14 // Terraform to build the graph that Terraform walks.
  15 type GraphBuilder interface {
  16         // Build builds the graph for the given module path. It is up to
  17         // the interface implementation whether this build should expand
  18         // the graph or not.
  19         Build(addrs.ModuleInstance) (*Graph, tfdiags.Diagnostics)
  20 }
  21
  22 // BasicGraphBuilder is a GraphBuilder that builds a graph out of a
  23 // series of transforms and (optionally) validates the graph is a valid
  24 // structure.
  25 type BasicGraphBuilder struct {
  26         Steps    []GraphTransformer
  27         Validate bool
  28         // Optional name to add to the graph debug log
  29         Name string
  30 }
  31
  32 func (b *BasicGraphBuilder) Build(path addrs.ModuleInstance) (*Graph, tfdiags.Diagnostics) {
  33         var diags tfdiags.Diagnostics
  34         g := &Graph{Path: path}
  35
  36         var lastStepStr string
  37         for _, step := range b.Steps {
  38                 if step == nil {
  39                         continue
  40                 }
  41                 log.Printf("[TRACE] Executing graph transform %T", step)
  42
  43                 stepName := fmt.Sprintf("%T", step)
  44                 dot := strings.LastIndex(stepName, ".")
  45                 if dot >= 0 {
  46                         stepName = stepName[dot+1:]
  47                 }
  48
  49                 debugOp := g.DebugOperation(stepName, "")
  50                 err := step.Transform(g)
  51
  52                 errMsg := ""
  53                 if err != nil {
  54                         errMsg = err.Error()
  55                 }
  56                 debugOp.End(errMsg)
  57
  58                 if thisStepStr := g.StringWithNodeTypes(); thisStepStr != lastStepStr {
  59                         log.Printf("[TRACE] Completed graph transform %T with new graph:\n%s------", step, thisStepStr)
  60                         lastStepStr = thisStepStr
  61                 } else {
  62                         log.Printf("[TRACE] Completed graph transform %T (no changes)", step)
  63                 }
  64
  65                 if err != nil {
  66                         if nf, isNF := err.(tfdiags.NonFatalError); isNF {
  67                                 diags = diags.Append(nf.Diagnostics)
  68                         } else {
  69                                 diags = diags.Append(err)
  70                                 return g, diags
  71                         }
  72                 }
  73         }
  74
  75         // Validate the graph structure
  76         if b.Validate {
  77                 if err := g.Validate(); err != nil {
  78                         log.Printf("[ERROR] Graph validation failed. Graph:\n\n%s", g.String())
  79                         diags = diags.Append(err)
  80                         return nil, diags
  81                 }
  82         }
  83
  84         return g, diags
  85 }