terraform/terraform/transform_provisioner.go

124 lines
3.4 KiB
Go

package terraform
import (
"fmt"
"github.com/hashicorp/go-multierror"
"github.com/hashicorp/terraform/dag"
)
// GraphNodeProvisioner is an interface that nodes that can be a provisioner
// must implement. The ProvisionerName returned is the name of the provisioner
// they satisfy.
type GraphNodeProvisioner interface {
ProvisionerName() string
}
// GraphNodeProvisionerConsumer is an interface that nodes that require
// a provisioner must implement. ProvisionedBy must return the name of the
// provisioner to use.
type GraphNodeProvisionerConsumer interface {
ProvisionedBy() []string
}
// ProvisionerTransformer is a GraphTransformer that maps resources to
// provisioners within the graph. This will error if there are any resources
// that don't map to proper resources.
type ProvisionerTransformer struct{}
func (t *ProvisionerTransformer) Transform(g *Graph) error {
// Go through the other nodes and match them to provisioners they need
var err error
m := provisionerVertexMap(g)
for _, v := range g.Vertices() {
if pv, ok := v.(GraphNodeProvisionerConsumer); ok {
for _, provisionerName := range pv.ProvisionedBy() {
target := m[provisionerName]
if target == nil {
err = multierror.Append(err, fmt.Errorf(
"%s: provisioner %s couldn't be found",
dag.VertexName(v), provisionerName))
continue
}
g.Connect(dag.BasicEdge(v, target))
}
}
}
return err
}
// MissingProvisionerTransformer is a GraphTransformer that adds nodes
// for missing provisioners into the graph. Specifically, it creates provisioner
// configuration nodes for all the provisioners that we support. These are
// pruned later during an optimization pass.
type MissingProvisionerTransformer struct {
// Provisioners is the list of provisioners we support.
Provisioners []string
}
func (t *MissingProvisionerTransformer) Transform(g *Graph) error {
m := provisionerVertexMap(g)
for _, p := range t.Provisioners {
if _, ok := m[p]; ok {
// This provisioner already exists as a configured node
continue
}
// Add our own missing provisioner node to the graph
g.Add(&graphNodeMissingProvisioner{ProvisionerNameValue: p})
}
return nil
}
// PruneProvisionerTransformer is a GraphTransformer that prunes all the
// provisioners that aren't needed from the graph. A provisioner is unneeded if
// no resource or module is using that provisioner.
type PruneProvisionerTransformer struct{}
func (t *PruneProvisionerTransformer) Transform(g *Graph) error {
for _, v := range g.Vertices() {
// We only care about the provisioners
if _, ok := v.(GraphNodeProvisioner); !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 graphNodeMissingProvisioner struct {
ProvisionerNameValue string
}
func (n *graphNodeMissingProvisioner) Name() string {
return fmt.Sprintf("provisioner.%s", n.ProvisionerNameValue)
}
// GraphNodeEvalable impl.
func (n *graphNodeMissingProvisioner) EvalTree() EvalNode {
return &EvalInitProvisioner{Name: n.ProvisionerNameValue}
}
func (n *graphNodeMissingProvisioner) ProvisionerName() string {
return n.ProvisionerNameValue
}
func provisionerVertexMap(g *Graph) map[string]dag.Vertex {
m := make(map[string]dag.Vertex)
for _, v := range g.Vertices() {
if pv, ok := v.(GraphNodeProvisioner); ok {
m[pv.ProvisionerName()] = v
}
}
return m
}