From dcab82e897fdb0d1bdd3ecefbd3492feca9c8075 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Mon, 3 Jun 2019 18:08:26 -0400
Subject: [PATCH] send and receive Private through ReadResource

Send Private data blob through ReadResource as well. This will allow for
extra flexibility for future providers that may want to pass data out of
band through to their resource Read functions.
---
 helper/plugin/grpc_provider.go | 5 +++++
 plugin/grpc_provider.go        | 2 ++
 providers/provider.go          | 8 ++++++++
 terraform/eval_refresh.go      | 2 ++
 4 files changed, 17 insertions(+)

diff --git a/helper/plugin/grpc_provider.go b/helper/plugin/grpc_provider.go
index 510f47f351..37d27c6104 100644
--- a/helper/plugin/grpc_provider.go
+++ b/helper/plugin/grpc_provider.go
@@ -535,6 +535,11 @@ func (s *GRPCProviderServer) ReadResource(_ context.Context, req *proto.ReadReso
 		Msgpack: newStateMP,
 	}
 
+	// helper/schema did previously handle private data during refresh, but
+	// core is now going to expect this to be maintained in order to
+	// persist it in the state.
+	resp.Private = req.Private
+
 	return resp, nil
 }
 
diff --git a/plugin/grpc_provider.go b/plugin/grpc_provider.go
index ae9a4002dd..5b190e2c18 100644
--- a/plugin/grpc_provider.go
+++ b/plugin/grpc_provider.go
@@ -330,6 +330,7 @@ func (p *GRPCProvider) ReadResource(r providers.ReadResourceRequest) (resp provi
 	protoReq := &proto.ReadResource_Request{
 		TypeName:     r.TypeName,
 		CurrentState: &proto.DynamicValue{Msgpack: mp},
+		Private:      r.Private,
 	}
 
 	protoResp, err := p.client.ReadResource(p.ctx, protoReq)
@@ -348,6 +349,7 @@ func (p *GRPCProvider) ReadResource(r providers.ReadResourceRequest) (resp provi
 		}
 	}
 	resp.NewState = state
+	resp.Private = protoResp.Private
 
 	return resp
 }
diff --git a/providers/provider.go b/providers/provider.go
index 1aa08c271d..7e0a74c58e 100644
--- a/providers/provider.go
+++ b/providers/provider.go
@@ -176,6 +176,10 @@ type ReadResourceRequest struct {
 
 	// PriorState contains the previously saved state value for this resource.
 	PriorState cty.Value
+
+	// Private is an opaque blob that will be stored in state along with the
+	// resource. It is intended only for interpretation by the provider itself.
+	Private []byte
 }
 
 type ReadResourceResponse struct {
@@ -184,6 +188,10 @@ type ReadResourceResponse struct {
 
 	// Diagnostics contains any warnings or errors from the method call.
 	Diagnostics tfdiags.Diagnostics
+
+	// Private is an opaque blob that will be stored in state along with the
+	// resource. It is intended only for interpretation by the provider itself.
+	Private []byte
 }
 
 type PlanResourceChangeRequest struct {
diff --git a/terraform/eval_refresh.go b/terraform/eval_refresh.go
index 03bc948115..4dfb5b4e93 100644
--- a/terraform/eval_refresh.go
+++ b/terraform/eval_refresh.go
@@ -55,6 +55,7 @@ func (n *EvalRefresh) Eval(ctx EvalContext) (interface{}, error) {
 	req := providers.ReadResourceRequest{
 		TypeName:   n.Addr.Resource.Type,
 		PriorState: priorVal,
+		Private:    state.Private,
 	}
 
 	provider := *n.Provider
@@ -87,6 +88,7 @@ func (n *EvalRefresh) Eval(ctx EvalContext) (interface{}, error) {
 
 	newState := state.DeepCopy()
 	newState.Value = resp.NewState
+	newState.Private = resp.Private
 
 	// Call post-refresh hook
 	err = ctx.Hook(func(h Hook) (HookAction, error) {