terraform/terraform/transform_provider.go

135 lines
3.4 KiB
Go

package terraform
import (
"fmt"
"github.com/hashicorp/go-multierror"
"github.com/hashicorp/terraform/dag"
)
// GraphNodeProvider is an interface that nodes that can be a provider
// must implement. The ProviderName returned is the name of the provider
// they satisfy.
type GraphNodeProvider interface {
ProviderName() string
}
// GraphNodeProviderConsumer is an interface that nodes that require
// a provider must implement. ProvidedBy must return the name of the provider
// to use.
type GraphNodeProviderConsumer interface {
ProvidedBy() []string
}
// ProviderTransformer is a GraphTransformer that maps resources to
// providers within the graph. This will error if there are any resources
// that don't map to proper resources.
type ProviderTransformer struct{}
func (t *ProviderTransformer) Transform(g *Graph) error {
// Go through the other nodes and match them to providers they need
var err error
m := providerVertexMap(g)
for _, v := range g.Vertices() {
if pv, ok := v.(GraphNodeProviderConsumer); ok {
for _, p := range pv.ProvidedBy() {
target := m[p]
if target == nil {
err = multierror.Append(err, fmt.Errorf(
"%s: provider %s couldn't be found",
dag.VertexName(v), p))
continue
}
g.Connect(dag.BasicEdge(v, target))
}
}
}
return err
}
// MissingProviderTransformer is a GraphTransformer that adds nodes
// for missing providers into the graph. Specifically, it creates provider
// configuration nodes for all the providers that we support. These are
// pruned later during an optimization pass.
type MissingProviderTransformer struct {
// Providers is the list of providers we support.
Providers []string
}
func (t *MissingProviderTransformer) Transform(g *Graph) error {
m := providerVertexMap(g)
for _, p := range t.Providers {
if _, ok := m[p]; ok {
// This provider already exists as a configured node
continue
}
// Add our own missing provider node to the graph
g.Add(&graphNodeMissingProvider{ProviderNameValue: p})
}
return nil
}
// PruneProviderTransformer is a GraphTransformer that prunes all the
// providers that aren't needed from the graph. A provider is unneeded if
// no resource or module is using that provider.
type PruneProviderTransformer struct{}
func (t *PruneProviderTransformer) Transform(g *Graph) error {
for _, v := range g.Vertices() {
// We only care about the providers
if _, ok := v.(GraphNodeProvider); !ok {
continue
}
// Does anything depend on this? If not, then prune it.
if s := g.UpEdges(v); s.Len() == 0 {
g.Remove(v)
}
}
return nil
}
type graphNodeMissingProvider struct {
ProviderNameValue string
}
func (n *graphNodeMissingProvider) Name() string {
return fmt.Sprintf("provider.%s", n.ProviderNameValue)
}
// GraphNodeEvalable impl.
func (n *graphNodeMissingProvider) EvalTree() EvalNode {
return ProviderEvalTree(n.ProviderNameValue, nil)
}
func (n *graphNodeMissingProvider) ProviderName() string {
return n.ProviderNameValue
}
// GraphNodeDotter impl.
func (n *graphNodeMissingProvider) Dot(name string) string {
return fmt.Sprintf(
"\"%s\" [\n"+
"\tlabel=\"%s\"\n"+
"\tshape=diamond\n"+
"];",
name,
n.Name())
}
func providerVertexMap(g *Graph) map[string]dag.Vertex {
m := make(map[string]dag.Vertex)
for _, v := range g.Vertices() {
if pv, ok := v.(GraphNodeProvider); ok {
m[pv.ProviderName()] = v
}
}
return m
}