core: NewInstanceInfo should take ResourceInstance, not Resource

On the initial pass here I reached a faulty conclusion about what from
the new world should shim into a NewInstanceInfo, based on a poor read
of existing code.

It actually _should've_ been based on an absolute instance after all,
as evidenced by the expected result of TestContext2Refresh_targetedCount.
Therefore the signature is changed here, and all of the callers (which,
in retrospect, were all holding a full instance address anyway!) are
updated to that new signature.

terraform/eval_apply.go

@@ -32,7 +32,7 @@ func (n *EvalApply) Eval(ctx EvalContext) (interface{}, error) {
 	state := *n.State
 
 	// The provider API still expects our legacy InstanceInfo type, so we must shim it.
-	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()).ContainingResource())
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	if diff.Empty() {
 		log.Printf("[DEBUG] apply %s: diff is empty, so skipping.", n.Addr)
@@ -113,7 +113,7 @@ func (n *EvalApplyPre) Eval(ctx EvalContext) (interface{}, error) {
 
 	// The hook API still uses our legacy InstanceInfo type, so we must
 	// shim it.
-	legacyInfo := NewInstanceInfo(n.Addr.ContainingResource().Absolute(ctx.Path()))
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	// If the state is nil, make it non-nil
 	if state == nil {
@@ -147,7 +147,7 @@ func (n *EvalApplyPost) Eval(ctx EvalContext) (interface{}, error) {
 
 	// The hook API still uses our legacy InstanceInfo type, so we must
 	// shim it.
-	legacyInfo := NewInstanceInfo(n.Addr.ContainingResource().Absolute(ctx.Path()))
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	if resourceHasUserVisibleApply(legacyInfo) {
 		// Call post-apply hook
@@ -199,7 +199,7 @@ func (n *EvalApplyProvisioners) Eval(ctx EvalContext) (interface{}, error) {
 	state := *n.State
 
 	// The hook API still uses the legacy InstanceInfo type, so we need to shim it.
-	legacyInfo := NewInstanceInfo(n.Addr.Resource.Absolute(ctx.Path()))
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	if n.CreateNew != nil && !*n.CreateNew {
 		// If we're not creating a new resource, then don't run provisioners
@@ -286,7 +286,7 @@ func (n *EvalApplyProvisioners) apply(ctx EvalContext, provs []*configs.Provisio
 	state := *n.State
 
 	// The hook API still uses the legacy InstanceInfo type, so we need to shim it.
-	legacyInfo := NewInstanceInfo(n.Addr.Resource.Absolute(ctx.Path()))
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	// Store the original connection info, restore later
 	origConnInfo := state.Ephemeral.ConnInfo

terraform/eval_diff.go

@@ -104,7 +104,7 @@ func (n *EvalDiff) Eval(ctx EvalContext) (interface{}, error) {
 	var diags tfdiags.Diagnostics
 
 	// The provider and hook APIs still expect our legacy InstanceInfo type.
-	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()).ContainingResource())
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	// State still uses legacy-style internal ids, so we need to shim to get
 	// a suitable key to use.
@@ -439,7 +439,7 @@ func (n *EvalDiffDestroy) Eval(ctx EvalContext) (interface{}, error) {
 	}
 
 	// The provider and hook APIs still expect our legacy InstanceInfo type.
-	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()).ContainingResource())
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	// Call pre-diff hook
 	err := ctx.Hook(func(h Hook) (HookAction, error) {

terraform/eval_read_data.go

@@ -37,7 +37,7 @@ func (n *EvalReadDataDiff) Eval(ctx EvalContext) (interface{}, error) {
 	var diags tfdiags.Diagnostics
 
 	// The provider and hook APIs still expect our legacy InstanceInfo type.
-	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()).ContainingResource())
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	err := ctx.Hook(func(h Hook) (HookAction, error) {
 		return h.PreDiff(legacyInfo, nil)
@@ -138,7 +138,7 @@ func (n *EvalReadDataApply) Eval(ctx EvalContext) (interface{}, error) {
 	diff := *n.Diff
 
 	// The provider and hook APIs still expect our legacy InstanceInfo type.
-	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()).ContainingResource())
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	// If the diff is for *destroying* this resource then we'll
 	// just drop its state and move on, since data resources don't

terraform/eval_refresh.go

@@ -22,7 +22,7 @@ func (n *EvalRefresh) Eval(ctx EvalContext) (interface{}, error) {
 	state := *n.State
 
 	// The provider and hook APIs still expect our legacy InstanceInfo type.
-	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()).ContainingResource())
+	legacyInfo := NewInstanceInfo(n.Addr.Absolute(ctx.Path()))
 
 	// If we have no state, we don't do any refreshing
 	if state == nil {

terraform/resource.go

@@ -105,10 +105,8 @@ type InstanceInfo struct {
 	uniqueExtra string
 }
 
-// NewInstanceInfo constructs an InstanceInfo from an addrs.AbsResource.
+// NewInstanceInfo constructs an InstanceInfo from an addrs.AbsResourceInstance.
 //
-// In spite of the confusing name, an InstanceInfo actually identifies a
-// particular resource rather than a particular resource instance.
 // InstanceInfo is a legacy type, and uses of it should be gradually replaced
 // by direct use of addrs.AbsResource or addrs.AbsResourceInstance as
 // appropriate.
@@ -117,7 +115,11 @@ type InstanceInfo struct {
 // keys, so this function will panic if given such a path. Uses of this type
 // should all be removed or replaced before implementing "count" and "for_each"
 // arguments on modules in order to avoid such panics.
-func NewInstanceInfo(addr addrs.AbsResource) *InstanceInfo {
+//
+// This legacy type also cannot represent resource instances with string
+// instance keys. It will panic if the given key is not either NoKey or an
+// IntKey.
+func NewInstanceInfo(addr addrs.AbsResourceInstance) *InstanceInfo {
 	// We need an old-style []string module path for InstanceInfo.
 	path := make([]string, len(addr.Module))
 	for i, step := range addr.Module {
@@ -132,15 +134,23 @@ func NewInstanceInfo(addr addrs.AbsResource) *InstanceInfo {
 	// a representation of the resource mode, and so it's impossible to
 	// determine from an InstanceInfo alone whether it is a managed or data
 	// resource that is being referred to.
-	id := fmt.Sprintf("%s.%s", addr.Resource.Type, addr.Resource.Name)
+	id := fmt.Sprintf("%s.%s", addr.Resource.Resource.Type, addr.Resource.Resource.Name)
-	if addr.Resource.Mode == addrs.DataResourceMode {
+	if addr.Resource.Resource.Mode == addrs.DataResourceMode {
 		id = "data." + id
 	}
+	if addr.Resource.Key != addrs.NoKey {
+		switch k := addr.Resource.Key.(type) {
+		case addrs.IntKey:
+			id = id + fmt.Sprintf(".%d", int(k))
+		default:
+			panic(fmt.Sprintf("NewInstanceInfo cannot convert resource instance with %T instance key", addr.Resource.Key))
+		}
+	}
 
 	return &InstanceInfo{
 		Id:         id,
 		ModulePath: path,
-		Type:       addr.Resource.Type,
+		Type:       addr.Resource.Resource.Type,
 	}
 }
 

terraform/transform_import_state.go

@@ -67,7 +67,7 @@ func (n *graphNodeImportState) Path() addrs.ModuleInstance {
 // GraphNodeEvalable impl.
 func (n *graphNodeImportState) EvalTree() EvalNode {
 	var provider ResourceProvider
-	info := NewInstanceInfo(n.Addr.ContainingResource())
+	info := NewInstanceInfo(n.Addr)
 
 	// Reset our states
 	n.states = nil