[BN-1018] Add gRPC Health Check Proto

[admiraladmirable]

Purpose

Add health check proto.

Approach

The proto comes from: https://github.com/grpc/grpc/blob/master/doc/health-checking.md

Testing

Built locally, implemented in Bifrrost, deployed to GKE and ensured that the grpc liveliness/readiness probes succeeded.

Tickets

[nandotorterolo]

Great PR, some suggestions.

• files structure
• enumeration comments

Package names should be in lowercase. Package names should have unique names based on the project name, and possibly based on the path of the file containing the protocol buffer type definitions.

https://protobuf.dev/programming-guides/style/#packages

In other folders proto file are organized by service/models, maybe you can do something like this.

• proto
  • health
    • service
      • health_rpc.proto
    • models
      • models.proto

models.proto

enum ServingStatus {
    // UNKNOWN means that there was a timeout hitting the head of the chain..
    UNKNOWN = 0;
    // SERVING means that all services are running as expected
    SERVING = 1;
    // NOT_SERVING means...
    NOT_SERVING = 2;
    // SERVICE_UNKNOWN means,  // Used only by the Watch method.
    SERVICE_UNKNOWN = 3;  
  }

health_rpc.proto

syntax = "proto3";

package co.topl.health.services;

service Health {
  rpc Check(HealthCheckRequest) returns (HealthCheckResponse);

  rpc Watch(HealthCheckRequest) returns (stream HealthCheckResponse);
}

message HealthCheckRequest {
 // service is a string that we must/should send for this reason.
  string service = 1;
}

message HealthCheckResponse {
  ServingStatus status = 1;
}

[admiraladmirable]

Great PR, some suggestions.

* files structure

* enumeration comments

Package names should be in lowercase. Package names should have unique names based on the project name, and possibly based on the path of the file containing the protocol buffer type definitions.

https://protobuf.dev/programming-guides/style/#packages

In other folders proto file are organized by service/models, maybe you can do something like this.

* proto
  
  * health
    
    * service
      
      * health_rpc.proto
    * models
      
      * models.proto

models.proto

enum ServingStatus {
    // UNKNOWN means that there was a timeout hitting the head of the chain..
    UNKNOWN = 0;
    // SERVING means that all services are running as expected
    SERVING = 1;
    // NOT_SERVING means...
    NOT_SERVING = 2;
    // SERVICE_UNKNOWN means,  // Used only by the Watch method.
    SERVICE_UNKNOWN = 3;  
  }

health_rpc.proto

syntax = "proto3";

package co.topl.health.services;

service Health {
  rpc Check(HealthCheckRequest) returns (HealthCheckResponse);

  rpc Watch(HealthCheckRequest) returns (stream HealthCheckResponse);
}

message HealthCheckRequest {
 // service is a string that we must/should send for this reason.
  string service = 1;
}

message HealthCheckResponse {
  ServingStatus status = 1;
}

@nandotorterolo Thanks for the review!

I'll update the folder format of the modes/services.

One note though, I don't believe that the built in gRPC health check in Kubernetes supports customizing the package/service path. I believe it must be grpc.health.v1.Health. Hopefully this is okay.

[nandotorterolo]

ok, I didn't know about Kubernetes customizations.
So, Kubernetes needs

• a package with this namespace: grpc.health.v1.Health
• the file should be in a folder with this path: 'google/..'

@nandotorterolo Thanks for the review!

I'll update the folder format of the modes/services.

One note though, I don't believe that the built in gRPC health check in Kubernetes supports customizing the package/service path. I believe it must be grpc.health.v1.Health. Hopefully this is okay.

[admiraladmirable]

ok, I didn't know about Kubernetes customizations. So, Kubernetes needs

* a package with this namespace:  `grpc.health.v1.Health`

* the file should be in a folder with this path: 'google/..'

@nandotorterolo Thanks for the review!
I'll update the folder format of the modes/services.
One note though, I don't believe that the built in gRPC health check in Kubernetes supports customizing the package/service path. I believe it must be grpc.health.v1.Health. Hopefully this is okay.

Yes, however the google/ folder path isn't necessarily required, but I just simplified it instead of a more complicated file structure. If we want to, I could structure the folder like:

grpc
| -- health
    | -- v1

Or whichever format makes more sense.