Docs assume --proto-path option is specified, relative path is required when it's not
/protos/health.proto: File does not reside within any path specified using --proto_path (or -I). You must specify a --proto_path which encompasses this file. Note that the proto_path must be an exact prefix of the .proto file names -- protoc is too dumb to figure out when two paths (e.g. absolute and relative) are equivalent (it's harder than you think).
Docs assume
--proto-path
option is specified, relative path is required when it's not