POC: Add GraphQL API for query service

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "jaeger-ui"]
 	path = jaeger-ui
 	url = https://github.com/jaegertracing/jaeger-ui.git
+[submodule "opentelemetry-proto"]
+	path = opentelemetry-proto
+	url = https://github.com/open-telemetry/opentelemetry-proto.git

Makefile

@@ -564,3 +564,43 @@ certs:
 .PHONY: certs-dryrun
 certs-dryrun:
 	cd pkg/config/tlscfg/testdata && ./gen-certs.sh -d
+
+
+### Dependencies
+DOCKER_PROTOBUF ?= otel/build-protobuf:0.2.1
+PROTOC = docker run --rm -u ${shell id -u} -v${PWD}:${PWD} -w${PWD} ${DOCKER_PROTOBUF} --proto_path=${PWD}
+PROTO_INTERMEDIATE_DIR = pkg/.patched-proto
+PROTO_INCLUDES = -I$(PROTO_INTERMEDIATE_DIR)
+PROTO_GEN = $(PROTOC) $(PROTO_INCLUDES) --gogofaster_out=plugins=grpc,paths=source_relative:$(2) $(1)
+
+.PHONY: gen-proto
+gen-proto:
+	@echo --
+	@echo -- Copying to $(PROTO_INTERMEDIATE_DIR)
+	@echo --
+	mkdir -p $(PROTO_INTERMEDIATE_DIR)
+	cp -R opentelemetry-proto/opentelemetry/proto/* $(PROTO_INTERMEDIATE_DIR)
+
+	@echo --
+	@echo -- Editing proto
+	@echo --
+
+	@# Update package and types from opentelemetry.proto.* -> tempopb.*
+	@# giving final types like "tempopb.common.v1.InstrumentationLibrary" which
+	@# will not conflict with other usages of opentelemetry proto in downstream apps.
+	find $(PROTO_INTERMEDIATE_DIR) -name "*.proto" | xargs -L 1 sed -i $(SED_OPTS) 's+ opentelemetry.proto+ jaeger+g'
+
+	@# Update go_package
+	find $(PROTO_INTERMEDIATE_DIR) -name "*.proto" | xargs -L 1 sed -i $(SED_OPTS) 's+github.com/open-telemetry/opentelemetry-proto/gen/go+github.com/jaegertracing/jaeger/pkg/otel+g'
+
+	@# Update import paths
+	find $(PROTO_INTERMEDIATE_DIR) -name "*.proto" | xargs -L 1 sed -i $(SED_OPTS) 's+import "opentelemetry/proto/+import "+g'
+
+	@echo --
+	@echo -- Gen proto --
+	@echo --
+	$(call PROTO_GEN,$(PROTO_INTERMEDIATE_DIR)/common/v1/common.proto,./pkg/otel/)
+	$(call PROTO_GEN,$(PROTO_INTERMEDIATE_DIR)/resource/v1/resource.proto,./pkg/otel/)
+	$(call PROTO_GEN,$(PROTO_INTERMEDIATE_DIR)/trace/v1/trace.proto,./pkg/otel/)
+
+	rm -rf $(PROTO_INTERMEDIATE_DIR)

cmd/query/app/gqlgen/gqlgen.yml

@@ -0,0 +1,67 @@
+# Where are all the schema files located? globs are supported eg  src/**/*.graphqls
+schema:
+  - graph/*.graphqls
+
+# Where should the generated server code go?
+exec:
+  filename: graph/generated/generated.go
+  package: generated
+
+# Where should any generated models go?
+model:
+  filename: graph/model/models_gen.go
+  package: model
+
+# Where should the resolver implementations go?
+resolver:
+  layout: follow-schema
+  dir: graph
+  package: graph
+
+# Optional: turn on use `gqlgen:"fieldName"` tags in your models
+# struct_tag: json
+
+# Optional: turn on to use []Thing instead of []*Thing
+# omit_slice_element_pointers: false
+
+# Optional: set to speed up generation time by not performing a final validation pass.
+# skip_validation: true
+
+# gqlgen will search for any type names in the schema in these go packages
+# if they match it will use them, otherwise it will generate them.
+autobind:
+  - "github.com/jaegertracing/jaeger/cmd/query/app/gqlgen/graph/model"
+
+# This section declares type mapping between the GraphQL and go type systems
+#
+# The first line in each type will be used as defaults for resolver arguments and
+# modelgen, the others will be allowed when binding to fields. Configure them to
+# your liking
+models:
+  Span:
+    model:
+     - github.com/jaegertracing/jaeger/pkg/otel/trace/v1.Span
+  ResourceSpans:
+    model:
+      - github.com/jaegertracing/jaeger/pkg/otel/trace/v1.ResourceSpans
+  InstrumentatationLibrarySpans:
+    model:
+      - github.com/jaegertracing/jaeger/pkg/otel/trace/v1.InstrumentationLibrarySpans
+  Resource:
+    model:
+      - github.com/jaegertracing/jaeger/pkg/otel/resource/v1.Resource
+  InstrumentationLibrary:
+    model:
+      - github.com/jaegertracing/jaeger/pkg/otel/common/v1.InstrumentationLibrary
+
+  # TODO remove following if not used
+  ID:
+    model:
+      - github.com/99designs/gqlgen/graphql.ID
+      - github.com/99designs/gqlgen/graphql.Int64
+      - github.com/99designs/gqlgen/graphql.IntID
+  Int:
+    model:
+      - github.com/99designs/gqlgen/graphql.Int
+      - github.com/99designs/gqlgen/graphql.Int64
+      - github.com/99designs/gqlgen/graphql.Int32