Protobuf timestamp not found

Question

Relatively new to GRPC and getting an error in my proto file that I cannot seem to make sense of. I would like to send a time in a message using the "google.protobuf.Timestamp". I cannot seem to import it. What am I doing wrong?

syntax = "proto3";
    
import "google/protobuf/timestamp.proto";
        
service ProfileService {
    rpc ConstructProfileStructFromUser (ConstructProfileStructFromUserRequest) returns (ConstructProfileStructFromUserResponse);
}
        
message ConstructProfileStructFromUserRequest {
    string transactionID = 1;
    string User = 2;
}
        
message ConstructProfileStructFromUserResponse {
    string UID = 1;
    string ContactEmail = 2;
    google.protobuf.Timestamp DateOfBirth = 3;
}

Both in my IDE and my compiler (using the below command) then I get the error

google/protobuf/timestamp.proto: File not found.
profile.proto: Import "google/protobuf/timestamp.proto" was not found or had errors.
profile.proto:21:5: "google.protobuf.Timestamp" is not defined.

Command to run:

protoc -I profile/ profile/profile.proto --go_out=plugins=grpc:profile

Protoc --version

libprotoc 3.0.0

Answer 1

I had this issue after installing the protoc compiler using the apt package manager (Ubuntu) and it put the protoc compiler somewhere like /usr/local/bin.

It seems by default protoc expects imports to be present in an include path relative to the protoc installation directory. For example:

• protoc location: /usr/local/bin/protoc
• include location: /usr/local/bin/include/*

Install pre-compiled binaries (any OS)

Downloading a pre-compiled binary as indicated below will have the needed include directory.

Instructions from grpc.io/docs/protoc-installation

1. Manually download from github.com/google/protobuf/releases the zip file corresponding to your operating system and computer architecture (protoc--.zip), or fetch the file using commands such as the following:

PB_REL="https://github.com/protocolbuffers/protobuf/releases"
curl -LO $PB_REL/download/v3.15.8/protoc-3.15.8-linux-x86_64.zip

2. Unzip the file under $HOME/.local or a directory of your choice. For example:

unzip protoc-3.15.8-linux-x86_64.zip -d $HOME/.local

3. Update your environment’s path variable to include the path to the protoc executable. For example:

export PATH="$PATH:$HOME/.local/bin"

Answer 2

If you installed protoc with your package manager, you only have to install the libprotobuf-dev (Ubuntu) or protobuf-devel (Fedora) package.

In general, you can find the containing package of a file on Ubuntu with apt-file find google/protobuf/timestamp.proto or on Fedora dnf repoquery --file "**/google/protobuf/timestamp.proto" (this is how I found the package I needed). Other package managers probably have similar commands.