opentofu/addrs/resource_phase.go
Martin Atkins 6bbfbab93e core: Produce correct references for destroy nodes
Prior to the introduction of our "addrs" package, we represented destroy
nodes as a special kind of address string ending in ".destroy" or
".destroy-cbd".

Using references to resolve these dependencies is a strange idea to begin
with, since these are not user-visible addresses, but rather than refactor
that now we instead have these weird pseudo-address types ResourcePhase
and ResourceInstancePhase that correspond go those weird address suffixes,
thus restoring the prior behavior.

In future we should rework this so that destroy node edges are not handled
as references at all, and instead handled as part of
DestroyEdgeTransformer where there's better context for implementing this
logic and it can be maintained and tested in a single place.
2018-10-16 18:49:20 -07:00

106 lines
3.9 KiB
Go

package addrs
import "fmt"
// ResourceInstancePhase is a special kind of reference used only internally
// during graph building to represent resource instances that are in a
// non-primary state.
//
// Graph nodes can declare themselves referenceable via an instance phase
// or can declare that they reference an instance phase in order to accomodate
// secondary graph nodes dealing with, for example, destroy actions.
//
// This special reference type cannot be accessed directly by end-users, and
// should never be shown in the UI.
type ResourceInstancePhase struct {
referenceable
ResourceInstance ResourceInstance
Phase ResourceInstancePhaseType
}
var _ Referenceable = ResourceInstancePhase{}
// Phase returns a special "phase address" for the receving instance. See the
// documentation of ResourceInstancePhase for the limited situations where this
// is intended to be used.
func (r ResourceInstance) Phase(rpt ResourceInstancePhaseType) ResourceInstancePhase {
return ResourceInstancePhase{
ResourceInstance: r,
Phase: rpt,
}
}
// ContainingResource returns an address for the same phase of the resource
// that this instance belongs to.
func (rp ResourceInstancePhase) ContainingResource() ResourcePhase {
return rp.ResourceInstance.Resource.Phase(rp.Phase)
}
func (rp ResourceInstancePhase) String() string {
// We use a different separator here than usual to ensure that we'll
// never conflict with any non-phased resource instance string. This
// is intentionally something that would fail parsing with ParseRef,
// because this special address type should never be exposed in the UI.
return fmt.Sprintf("%s#%s", rp.ResourceInstance, rp.Phase)
}
// ResourceInstancePhaseType is an enumeration used with ResourceInstancePhase.
type ResourceInstancePhaseType string
const (
// ResourceInstancePhaseDestroy represents the "destroy" phase of a
// resource instance.
ResourceInstancePhaseDestroy ResourceInstancePhaseType = "destroy"
// ResourceInstancePhaseDestroyCBD is similar to ResourceInstancePhaseDestroy
// but is used for resources that have "create_before_destroy" set, thus
// requiring a different dependency ordering.
ResourceInstancePhaseDestroyCBD ResourceInstancePhaseType = "destroy-cbd"
)
func (rpt ResourceInstancePhaseType) String() string {
return string(rpt)
}
// ResourcePhase is a special kind of reference used only internally
// during graph building to represent resources that are in a
// non-primary state.
//
// Graph nodes can declare themselves referenceable via a resource phase
// or can declare that they reference a resource phase in order to accomodate
// secondary graph nodes dealing with, for example, destroy actions.
//
// Since resources (as opposed to instances) aren't actually phased, this
// address type is used only as an approximation during initial construction
// of the resource-oriented plan graph, under the assumption that resource
// instances with ResourceInstancePhase addresses will be created in dynamic
// subgraphs during the graph walk.
//
// This special reference type cannot be accessed directly by end-users, and
// should never be shown in the UI.
type ResourcePhase struct {
referenceable
Resource Resource
Phase ResourceInstancePhaseType
}
var _ Referenceable = ResourcePhase{}
// Phase returns a special "phase address" for the receving instance. See the
// documentation of ResourceInstancePhase for the limited situations where this
// is intended to be used.
func (r Resource) Phase(rpt ResourceInstancePhaseType) ResourcePhase {
return ResourcePhase{
Resource: r,
Phase: rpt,
}
}
func (rp ResourcePhase) String() string {
// We use a different separator here than usual to ensure that we'll
// never conflict with any non-phased resource instance string. This
// is intentionally something that would fail parsing with ParseRef,
// because this special address type should never be exposed in the UI.
return fmt.Sprintf("%s#%s", rp.Resource, rp.Phase)
}