Add support for SELinux Systems.

* Gave the false trail that the file does not exist.

Makefile

@@ -13,12 +13,19 @@ $(1)
 
 endef
 
+# Make docker work when running on SELinux Enforcing Systems.
+ifeq ($(shell getenforce),Enforcing)
+	USE_MOUNT_OPTION := :Z
+else
+	USE_MOUNT_OPTION :=
+endif
+
 # Generate all implementations
 .PHONY: gen-all
 gen-all: gen-cpp gen-csharp gen-go gen-java gen-objc gen-openapi gen-php gen-python gen-ruby
 
 OTEL_DOCKER_PROTOBUF ?= otel/build-protobuf:0.4.0
-PROTOC := docker run --rm -u ${shell id -u} -v${PWD}:${PWD} -w${PWD} ${OTEL_DOCKER_PROTOBUF} --proto_path=${PWD}
+PROTOC := docker run --rm -u ${shell id -u} -v${PWD}:${PWD}$(USE_MOUNT_OPTION) -w${PWD} ${OTEL_DOCKER_PROTOBUF} --proto_path=${PWD}
 PROTO_INCLUDES := -I/usr/include/github.com/gogo/protobuf
 
 PROTO_GEN_CPP_DIR ?= $(GENDIR)/cpp