terraform/terraform/transform_orphan_resource.go

180 lines
5.7 KiB
Go

package terraform
import (
"log"
"github.com/hashicorp/terraform/configs"
"github.com/hashicorp/terraform/dag"
"github.com/hashicorp/terraform/states"
)
// OrphanResourceInstanceTransformer is a GraphTransformer that adds orphaned
// resource instances to the graph. An "orphan" is an instance that is present
// in the state but belongs to a resource that is no longer present in the
// configuration.
//
// This is not the transformer that deals with "count orphans" (instances that
// are no longer covered by a resource's "count" or "for_each" setting); that's
// handled instead by OrphanResourceCountTransformer.
type OrphanResourceInstanceTransformer struct {
Concrete ConcreteResourceInstanceNodeFunc
// State is the global state. We require the global state to
// properly find module orphans at our path.
State *states.State
// Config is the root node in the configuration tree. We'll look up
// the appropriate note in this tree using the path in each node.
Config *configs.Config
}
func (t *OrphanResourceInstanceTransformer) Transform(g *Graph) error {
if t.State == nil {
// If the entire state is nil, there can't be any orphans
return nil
}
if t.Config == nil {
// Should never happen: we can't be doing any Terraform operations
// without at least an empty configuration.
panic("OrphanResourceInstanceTransformer used without setting Config")
}
// Go through the modules and for each module transform in order
// to add the orphan.
for _, ms := range t.State.Modules {
if err := t.transform(g, ms); err != nil {
return err
}
}
return nil
}
func (t *OrphanResourceInstanceTransformer) transform(g *Graph, ms *states.Module) error {
if ms == nil {
return nil
}
moduleAddr := ms.Addr
// Get the configuration for this module. The configuration might be
// nil if the module was removed from the configuration. This is okay,
// this just means that every resource is an orphan.
var m *configs.Module
if c := t.Config.DescendentForInstance(moduleAddr); c != nil {
m = c.Module
}
// An "orphan" is a resource that is in the state but not the configuration,
// so we'll walk the state resources and try to correlate each of them
// with a configuration block. Each orphan gets a node in the graph whose
// type is decided by t.Concrete.
//
// We don't handle orphans related to changes in the "count" and "for_each"
// pseudo-arguments here. They are handled by OrphanResourceCountTransformer.
for _, rs := range ms.Resources {
if m != nil {
if r := m.ResourceByAddr(rs.Addr); r != nil {
continue
}
}
for key := range rs.Instances {
addr := rs.Addr.Instance(key).Absolute(moduleAddr)
abstract := NewNodeAbstractResourceInstance(addr)
var node dag.Vertex = abstract
if f := t.Concrete; f != nil {
node = f(abstract)
}
log.Printf("[TRACE] OrphanResourceInstanceTransformer: adding single-instance orphan node for %s", addr)
g.Add(node)
}
}
return nil
}
// OrphanResourceTransformer is a GraphTransformer that adds orphaned
// resources to the graph. An "orphan" is a resource that is present in
// the state but no longer present in the config.
//
// This is separate to OrphanResourceInstanceTransformer in that it deals with
// whole resources, rather than individual instances of resources. Orphan
// resource nodes are only used during apply to clean up leftover empty
// resource state skeletons, after all of the instances inside have been
// removed.
//
// This transformer will also create edges in the graph to any pre-existing
// node that creates or destroys the entire orphaned resource or any of its
// instances, to ensure that the "orphan-ness" of a resource is always dealt
// with after all other aspects of it.
type OrphanResourceTransformer struct {
Concrete ConcreteResourceNodeFunc
// State is the global state.
State *states.State
// Config is the root node in the configuration tree.
Config *configs.Config
}
func (t *OrphanResourceTransformer) Transform(g *Graph) error {
if t.State == nil {
// If the entire state is nil, there can't be any orphans
return nil
}
if t.Config == nil {
// Should never happen: we can't be doing any Terraform operations
// without at least an empty configuration.
panic("OrphanResourceTransformer used without setting Config")
}
// We'll first collect up the existing nodes for each resource so we can
// create dependency edges for any new nodes we create.
deps := map[string][]dag.Vertex{}
for _, v := range g.Vertices() {
switch tv := v.(type) {
case GraphNodeResourceInstance:
k := tv.ResourceInstanceAddr().ContainingResource().String()
deps[k] = append(deps[k], v)
case GraphNodeResource:
k := tv.ResourceAddr().String()
deps[k] = append(deps[k], v)
case GraphNodeDestroyer:
k := tv.DestroyAddr().ContainingResource().String()
deps[k] = append(deps[k], v)
}
}
for _, ms := range t.State.Modules {
moduleAddr := ms.Addr
mc := t.Config.DescendentForInstance(moduleAddr) // might be nil if whole module has been removed
for _, rs := range ms.Resources {
if mc != nil {
if r := mc.Module.ResourceByAddr(rs.Addr); r != nil {
// It's in the config, so nothing to do for this one.
continue
}
}
addr := rs.Addr.Absolute(moduleAddr)
abstract := NewNodeAbstractResource(addr)
var node dag.Vertex = abstract
if f := t.Concrete; f != nil {
node = f(abstract)
}
log.Printf("[TRACE] OrphanResourceTransformer: adding whole-resource orphan node for %s", addr)
g.Add(node)
for _, dn := range deps[addr.String()] {
log.Printf("[TRACE] OrphanResourceTransformer: node %q depends on %q", dag.VertexName(node), dag.VertexName(dn))
g.Connect(dag.BasicEdge(node, dn))
}
}
}
return nil
}