terraform/terraform/transform_attach_state.go

69 lines
2.1 KiB
Go

package terraform
import (
"log"
"github.com/hashicorp/terraform/dag"
"github.com/hashicorp/terraform/states"
)
// GraphNodeAttachResourceState is an interface that can be implemented
// to request that a ResourceState is attached to the node.
//
// Due to a historical naming inconsistency, the type ResourceState actually
// represents the state for a particular _instance_, while InstanceState
// represents the values for that instance during a particular phase
// (e.g. primary vs. deposed). Consequently, GraphNodeAttachResourceState
// is supported only for nodes that represent resource instances, even though
// the name might suggest it is for containing resources.
type GraphNodeAttachResourceState interface {
GraphNodeResourceInstance
// Sets the state
AttachResourceState(*states.Resource)
}
// AttachStateTransformer goes through the graph and attaches
// state to nodes that implement the interfaces above.
type AttachStateTransformer struct {
State *states.State // State is the root state
}
func (t *AttachStateTransformer) Transform(g *Graph) error {
// If no state, then nothing to do
if t.State == nil {
log.Printf("[DEBUG] Not attaching any node states: overall state is nil")
return nil
}
for _, v := range g.Vertices() {
// Nodes implement this interface to request state attachment.
an, ok := v.(GraphNodeAttachResourceState)
if !ok {
continue
}
addr := an.ResourceInstanceAddr()
rs := t.State.Resource(addr.ContainingResource())
if rs == nil {
log.Printf("[DEBUG] Resource state not found for node %q, instance %s", dag.VertexName(v), addr)
continue
}
is := rs.Instance(addr.Resource.Key)
if is == nil {
// We don't actually need this here, since we'll attach the whole
// resource state, but we still check because it'd be weird
// for the specific instance we're attaching to not to exist.
log.Printf("[DEBUG] Resource instance state not found for node %q, instance %s", dag.VertexName(v), addr)
continue
}
// make sure to attach a copy of the state, so instances can modify the
// same ResourceState.
an.AttachResourceState(rs.DeepCopy())
}
return nil
}