grpc-ts-health-check

gRPC Health Check

An implementation of gRPC health checks, written in typescript.

It is assumed that you are using the @grpc/grpc-js library.

Installation

yarn add grpc-ts-health-check

Install the @grpc/grpc-js library:

yarn add @grpc/grpc-js

Dependencies

• Google Protobuf: Protocol Buffers - Google's data interchange format.
• gRPC Boom: A zero dependency library to help create gRPC-friendly error objects.

Usage

import * as grpc from '@grpc/grpc-js';
import * as protoLoader from '@grpc/proto-loader';
import path from 'path';

import { HealthClient } from '../dist/proto/grpc/health/v1/Health';
import { HealthCheckResponse__Output } from '../dist/proto/grpc/health/v1/HealthCheckResponse';
import { ProtoGrpcType } from '../dist/proto/health';

export class HealthGrpcClient {
  private readonly client: HealthClient;

  constructor({ host, port }: { host: string; port: number }) {
    const packageDefinition = protoLoader.loadSync(path.resolve('../dist/proto/health.proto'), {
      arrays: true,
      keepCase: true,
      longs: String,
      enums: String,
      objects: true,
      defaults: true,
    });
    const proto = grpc.loadPackageDefinition(packageDefinition) as unknown as ProtoGrpcType;
    this.client = new proto.grpc.health.v1.Health(
      `${host}:${port}`,
      grpc.ChannelCredentials.createInsecure(),
    );
  }

  checkStatus(): Promise<HealthCheckResponse__Output> {
    return new Promise((resolve, reject) => {
      this.client.check(
        { service: 'example' },
        (error?: grpc.ServiceError | null, result?: HealthCheckResponse__Output): void => {
          if (error) {
            reject(error);
          }
          resolve(result || ({} as HealthCheckResponse__Output));
        },
      );
    });
  }

  watchStatus(): grpc.ClientReadableStream<HealthCheckResponse__Output> {
    return this.client.watch({ service: 'example' });
  }
}

Methods

Below is a list of available methods:

check(request, callback)

Checks the status of the service once.

• request - the HealthCheckRequest object.
• callback (optional) - the callback method.

watch(request)

Set the initial status of the service and continues to watch for any changes.

• request - the HealthCheckRequest object.

License

MIT License

Contributing

Contributions are encouraged, please see further details below:

Pull Requests

Here are some basic rules to follow to ensure timely addition of your request:

• Match coding style (braces, spacing, etc.).
• If it is a feature, bugfix, or anything please only change the minimum amount of code required to satisfy the change.
• Please keep PR titles easy to read and descriptive of changes, this will make them easier to merge.
• Pull requests must be made against the main branch. Any other branch (unless specified by the maintainers) will get rejected.
• Check for existing issues first, before filing a new issue.