How do you share gRPC proto definitions between services

In a multi-service architecture, sharing gRPC protocol definitions is a common practice to ensure consistency and efficiency in communication between different services. There are several ways to implement sharing gRPC protocol definitions, and I will detail the most commonly used methods with examples:

1. Using a Dedicated Git Repository to Manage Proto Files

This is a widely adopted approach. Create a separate Git repository to store all .proto files. This way, different services can reference this repository to share identical protocol definitions.

Example: Suppose services A and B need to share gRPC definitions related to users. Create a repository named common-protos and place user-related proto files (e.g., user.proto) within it. Services A and B can reference these definitions by using Git submodules or by directly copying the files into their respective projects.

Steps:

• Create the Git repository common-protos;
• Push the common .proto files to this repository;
• In the projects of services A and B, reference the common-protos repository using Git submodules or other methods.

2. Using Package Managers and Artifact Repositories

For languages supporting package managers (e.g., Maven or Gradle for Java), you can publish compiled code (e.g., Java JAR files) to internal or public artifact repositories.

Example: If using Java, compile the .proto files into Java code and publish the generated JAR package to Maven Central or a company’s internal Nexus repository. Other services can then add a dependency on this JAR package in their build configuration.

Steps:

• Design and write the .proto files;
• Use the protoc compiler to generate code in the target language;
• Package and publish the generated code to Maven, NPM, or other package management systems;
• In services requiring these protocol definitions, add the dependency via the package manager.

3. Using Dedicated Configuration Management Services

In large-scale projects or complex environments, configuration management services (e.g., Consul or etcd) may be used to store and distribute configuration files, including gRPC .proto files.

Example: Store the .proto files in Consul’s KV store. Each service can pull the latest .proto files from Consul upon startup and dynamically compile and use them.

Steps:

• Upload the .proto files to configuration management systems like Consul;
• When a service starts, pull the .proto files from the configuration management system;
• Dynamically compile and apply these definitions.

Summary

There are multiple ways to share gRPC protocol definitions, and the choice depends on the team’s specific needs, project scale, and existing technology stack. Git repositories are the simplest and most versatile method, suitable for most scenarios. Package managers and artifact repositories are ideal for environments with strict language requirements and version management. Configuration management services are appropriate for complex systems requiring highly dynamic configurations.