C# - etcd GRPC Client Basic Auth

Question

I am trying to implement a C# GRPC client for etcd v3+.I am able to connect via no auth and channel ssl auth.However, I am trying to figure out basic authentication mechanism as well.Here's my implementation till now.

using System;
using System.Threading.Tasks;
using System.Collections.Generic;
using Grpc.Core;
using Etcdserverpb;
using Google.Protobuf;
using System.Runtime.CompilerServices;
using Grpc.Auth;
using Grpc.Core.Interceptors;

namespace myproj.etcd
{
    public class EtcdClient
    {       
        Channel channel;
        KV.KVClient kvClient;
        string host;
        string username;
        string password;
        string authToken;
        Auth.AuthClient authClient;

        public EtcdClient(string host, string username, string password)
        {
            this.username = username;
            this.password = password;
            this.host = host;                

             Authenticate();

            // Expirementing with the token, trying to achieve my goal.
            channel = new Channel(host, ChannelCredentials.Create(ChannelCredentials.Insecure,
                                                                GoogleGrpcCredentials.FromAccessToken(this.authToken)));
            // This works.
            //channel = new Channel(host, ChannelCredentials.Insecure);

            kvClient = new KV.KVClient(channel);

        }

        void Authenticate()
        {
            authClient = new Auth.AuthClient(new Channel(host,ChannelCredentials.Insecure));
            var authRes = authClient.Authenticate(new AuthenticateRequest
            {
                Name = username,
                Password = password
            });

            this.authToken = authRes.Token;

        }

        public string Get(string key)
        {
            try
            {
                var rangeRequest = new RangeRequest { Key = ByteString.CopyFromUtf8(key) };
                var rangeResponse = kvClient.Range(rangeRequest);
                if (rangeResponse.Count != 0)
                {
                    return rangeResponse.Kvs[0].Value.ToStringUtf8().Trim();
                }
            }
            catch (Exception ex)
            {

            }
            return String.Empty;
        }

    }
}

Using the authenticate() method I am able to get the token from etcd server but unable to find a way to use the same in subsequent calls (Get, Put etc.).

Protobuf doc used for generating client code can be found here

Update: In case anyone wanna have a look at the full source code , here's the link to project.

Answer 1

I solved it by referring to REST api docs here.

Add a private property.

Metadata headers;

Updated Autheticate() to add auth header.

headers = new Metadata();
headers.Add("Authorization", authToken);

Updated Get() to pass header.

var rangeResponse = kvClient.Range(rangeRequest, headers);