- Bot now takes shard id (optional) and total shards (optional) command line arguments (changed from shard id and parent process id)

- Sharding with coordinator now works properly
- Documented creds.yml RestartCommand - it has no effect when coordinator is starting the bot
- Regenerated creds_example.yml
- Removed all db migrators as the v3 requires the user to have updated 2.x all the way
- TotalShards in creds.yml gets overriden by coord.yml's TotalShards if the bot is ran through coordinator (more precisely, by the command line argument to the bot)
- Coordinator now runs on http://localhost:3442 by default, you can change this in appsettings.json
    - This is done because of macos https issues
    - Primarily because https for regular users is a massive hassle. Coordinator shouldn't be exposed anyway
- Minor cleanup

src/NadekoBot/Services/Impl/BotCredsProvider.cs

@@ -1,7 +1,9 @@
-using Microsoft.Extensions.Configuration;
+using System;
+using Microsoft.Extensions.Configuration;
 using System.IO;
 using Microsoft.Extensions.Primitives;
 using Nadeko.Common;
+using NadekoBot.Common;
 using NadekoBot.Common.Yml;
 using Serilog;
 
@@ -10,6 +12,7 @@ namespace NadekoBot.Services
     // todo check why is memory usage so unstable
     public class BotCredsProvider
     {
+        private readonly int? _totalShards;
         private const string _credsFileName = "creds.yml";
         private string CredsPath => Path.Combine(Directory.GetCurrentDirectory(), _credsFileName);
         private const string _credsExampleFileName = "creds_example.yml";
@@ -28,12 +31,42 @@ namespace NadekoBot.Services
                 _creds.OwnerIds.Clear();
                 _config.Bind(_creds);
                 
-                // todo load defaults for restart command, redis, and some others maybe?
+                if (string.IsNullOrWhiteSpace(_creds.Token))
+                {
+                    Log.Error("Token is missing from credentials.json or Environment variables.\n" +
+                              "Add it and restart the program.");
+                    Helpers.ReadErrorAndExit(5);
+                    return;
+                }
+                
+                if (string.IsNullOrWhiteSpace(_creds.RestartCommand?.Cmd)
+                    || string.IsNullOrWhiteSpace(_creds.RestartCommand?.Args))
+                {
+                    if (Environment.OSVersion.Platform == PlatformID.Unix)
+                    {
+                        _creds.RestartCommand = new RestartConfig()
+                        {
+                            Args = "dotnet",
+                            Cmd = "NadekoBot.dll -- {0}",
+                        };
+                    }
+                    else
+                    {
+                        _creds.RestartCommand = new RestartConfig()
+                        {
+                            Args = "NadekoBot.exe",
+                            Cmd = "{0}",
+                        };
+                    }
+                }
+
+                _creds.TotalShards = _totalShards ?? _creds.TotalShards;
             }
         }
 
-        public BotCredsProvider()
+        public BotCredsProvider(int? totalShards = null)
         {
+            _totalShards = totalShards;
             if (!File.Exists(CredsExamplePath))
             {
                 File.WriteAllText(CredsExamplePath, Yaml.Serializer.Serialize(_creds));

src/NadekoBot/Services/Impl/RemoteGrpcCoordinator.cs

@@ -20,8 +20,11 @@ namespace NadekoBot.Services
 
         public RemoteGrpcCoordinator(IBotCredentials creds, DiscordSocketClient client)
         {
-            // todo should use credentials
-            var channel = Grpc.Net.Client.GrpcChannel.ForAddress("https://localhost:3443");
+            var coordUrl = string.IsNullOrWhiteSpace(creds.CoordinatorUrl)
+                ? "http://localhost:3442"
+                : creds.CoordinatorUrl;
+            
+            var channel = Grpc.Net.Client.GrpcChannel.ForAddress(coordUrl);
             _coordClient = new(channel);
             _client = client;
         }
@@ -29,8 +32,8 @@ namespace NadekoBot.Services
         public bool RestartBot()
         {
             _coordClient.RestartAllShards(new RestartAllRequest
-            { 
-
+            {
+                
             });
 
             return true;