grpc-slides/docs/practical_grpc.md

A practical guide to gRPC with

Victor Martinez

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Contents

• Ingredients to build a gRPC API
• Defining our API with Protocol Buffers
  • Defining a request
  • Defining a response
  • About backwards compatibility
  • Defining a service
• Generate a Rust library
  • Manual project setup
  • Build script
  • Exposing a library
  • Supporting multiple tonic versions
• CI/CD
  • The Buf tool
  • Checking for breaking changes
  • How to release

• Implementing a gRPC service
  • Implementing the service trait
  • Parsing requests
  • Error handling
• Building a gRPC server
  • Authentication
  • Tracing
  • Running our server
• How to deploy
• How to call our server
  • Creating a gRPC client
  • Authentication
  • Response handling
• How is it going so far
  • Users
  • Metrics

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Ingredients to build a gRPC API

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Defining our API

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Project structure

https://github.com/primait/es-policy-grpc

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Project structure

https://github.com/primait/es-policy-grpc

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Defining a request

syntax = "proto3";

package es_policy_grpc.messages.issue_policy.request.v1;

import "es_policy_grpc/domain/v1/bundle.proto";
import "es_policy_grpc/domain/v1/coverage.proto";
import "es_policy_grpc/domain/v1/issuing_company.proto";
// ... etc

message IssuePolicyRequest {
  google.protobuf.Timestamp requested_at = 1; 
  google.protobuf.Timestamp start_at = 2;
  google.protobuf.Timestamp end_at = 3;
  google.protobuf.Timestamp purchased_at = 4;
  es_policy_grpc.domain.v1.TransactionInformation transaction = 5;
  es_policy_grpc.domain.v1.IssuingCompany issuing_company = 6;
  string quote_id = 7;
  es_policy_grpc.domain.v1.QuoteSource quote_source = 8;
  string application_id = 9;
  string offer_id = 10;
  es_policy_grpc.domain.v1.Price price = 11;
  es_policy_grpc.domain.v1.Bundle bundle = 12;
  repeated es_policy_grpc.domain.v1.ProductCover covers = 13;
  es_policy_grpc.domain.v1.PolicyHolderInformation policy_holder_information = 14;
  es_policy_grpc.domain.v1.VehicleInformation vehicle_information = 15;
  es_policy_grpc.domain.v1.QuoteVersion quote_version = 16;
} 

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Defining a request

syntax = "proto3";

package es_policy_grpc.domain.v1;

import "es_policy_grpc/domain/v1/price.proto";
import "google/protobuf/timestamp.proto";

message ProductCover {
  CoverType cover_type = 1;
  google.protobuf.Timestamp start_at = 2;
  google.protobuf.Timestamp end_at = 3;
  es_policy_grpc.domain.v1.Price price = 4;
  optional RoadsideAssistanceTier roadside_assistance_tier = 5;
}

enum CoverType {
  COVER_TYPE_UNSPECIFIED = 0;
  COVER_TYPE_MANDATORY_THIRD_PARTY_LIABILITY = 1;
  COVER_TYPE_VOLUNTARY_THIRD_PARTY_LIABILITY = 2;
  COVER_TYPE_DRIVER_ACCIDENT = 3;
  COVER_TYPE_WINDSHIELD = 4;
  COVER_TYPE_THEFT = 5;
  // ..etc
}

enum RoadsideAssistanceTier {
  ROADSIDE_ASSISTANCE_TIER_UNSPECIFIED = 0;
  ROADSIDE_ASSISTANCE_TIER_BASE = 1;
  ROADSIDE_ASSISTANCE_TIER_PREMIUM = 2;
  ROADSIDE_ASSISTANCE_TIER_PREMIUM_V2 = 3;
}

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Defining a response

syntax = "proto3";

package es_policy_grpc.messages.issue_policy.response.v1;

message IssuePolicyResponse {
  string policy_id = 1;
}

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About backwards compatibility