Added hints support to store protobuf

CHANGELOG.md

@@ -15,6 +15,10 @@ We use *breaking* word for marking changes that are not backward compatible (rel
 
 - [#2501](https://github.com/thanos-io/thanos/pull/2501) Query: gracefully handle additional fields in `SeriesResponse` protobuf message that may be added in the future.
 
+### Added
+
+- [#2502](https://github.com/thanos-io/thanos/pull/2502) Added `hints` field to `SeriesResponse`. Hints in an opaque data structure that can be used to carry additional information from the store and its content is implementation specific.
+
 ### Changed
 
 - [#2505](https://github.com/thanos.io/thanos/pull/2505) Store: remove obsolete `thanos_store_node_info` metric.

pkg/store/storepb/rpc.proto

@@ -7,6 +7,7 @@ package thanos;
 import "types.proto";
 import "gogoproto/gogo.proto";
 import "prompb/types.proto";
+import "google/protobuf/any.proto";
 
 option go_package = "storepb";
 
@@ -132,6 +133,13 @@ message SeriesResponse {
     /// warning is considered an information piece in place of series for warning purposes.
     /// It is used to warn query customer about suspicious cases or partial response (if enabled).
     string warning = 2;
+
+    /// hints is an opaque data structure that can be used to carry additional information from
+    /// the store. The content of this field and whether it's supported depends on the
+    /// implementation of a specific store. It's also implementation specific if it's allowed that
+    /// multiple SeriesResponse frames contain hints for a single Series() request and how should they
+    /// be handled in such case (ie. merged vs keep the first/last one).
+    google.protobuf.Any hints = 3;
   }
 }
 

scripts/genproto.sh

@@ -29,17 +29,14 @@ DIRS="pkg/store/storepb pkg/store/storepb/prompb"
 echo "generating code"
 for dir in ${DIRS}; do
 	pushd ${dir}
-		${PROTOC_BIN} --gogofast_out=plugins=grpc:. \
+		${PROTOC_BIN} --gogofast_out=\
+Mgoogle/protobuf/any.proto=github.com/gogo/protobuf/types,\
+Mprompb/types.proto=github.com/thanos-io/thanos/pkg/store/storepb/prompb,\
+plugins=grpc:. \
 		  -I=. \
 			-I="${GOGOPROTO_PATH}" \
 			*.proto
 
-		sed -i.bak -E 's/import _ \"gogoproto\"//g' *.pb.go
-		sed -i.bak -E 's/import _ \"google\/protobuf\"//g' *.pb.go
-		# Hacky hack.
-		sed -i.bak -E 's/prompb \"prompb\"/prompb \"github.com\/thanos-io\/thanos\/pkg\/store\/storepb\/prompb\"/g' *.pb.go
-
-		rm -f *.bak
 		${GOIMPORTS_BIN} -w *.pb.go
 	popd
 done