mc-god/cmd/mcgod/main.go

package main

import (
	"context"
	"fmt"
	"log"
	"log/slog"
	"os"
	"os/signal"
	"sync"
	"syscall"
	"time"

	"github.com/gogo/protobuf/proto"
	"github.com/ollama/ollama/api"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	"tipsy.codes/charles/mc-god/v2/internal/pkg/logs"
	"tipsy.codes/charles/mc-god/v2/internal/pkg/rcon"
)

type chatContext struct {
	chatRequest *api.ChatRequest
	totalSize   int
	maxSize     int
	mu          sync.Mutex
}

func (c *chatContext) AddLog(msg string) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.chatRequest.Messages = append(c.chatRequest.Messages, api.Message{
		Role:    "logs",
		Content: msg,
	})
	c.totalSize += len(msg)
	c.truncate()
}

func (c *chatContext) AddSelf(msg api.Message) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.chatRequest.Messages = append(c.chatRequest.Messages, msg)
	c.totalSize += len(msg.Content)
	c.truncate()
}

func (c *chatContext) truncate() {
	for c.maxSize != 0 && c.totalSize > c.maxSize && len(c.chatRequest.Messages) > 0 {
		t := c.chatRequest.Messages[0]
		c.chatRequest.Messages = c.chatRequest.Messages[1:]
		c.totalSize -= len(t.Content)
	}
}

func main() {
	// Create a context that will be cancelled on interrupt signals
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	_ = ctx

	// Set up signal handling for graceful shutdown
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
	go func() {
		<-sigChan
		slog.Info("received interrupt signal, shutting down...")
		cancel()
	}()

	// Create RCON client from environment variables
	log.Println("Connecting to Minecraft server via RCON...")
	client, err := rcon.NewFromEnv()
	if err != nil {
		slog.Error("failed to create RCON client", "error", err)
		return
	}
	defer func() {
		if err := client.Close(); err != nil {
			slog.Warn("error closing RCON connection", "error", err)
		}
	}()

	// Perform a health check
	log.Println("Performing healthcheck...")
	if err := client.HealthCheck(); err != nil {
		slog.Error("Health check failed", "error", err)
		return
	}
	log.Println("Connected successfully!")

	// Create Kubernetes client
	kClient, err := createKubernetesClient()
	if err != nil {
		slog.Error("failed to create kubernetes client", "error", err)
		return
	}
	slog.Info("got kubernetes config")

	tailer, done := logs.LoggerFromEnv().Start(ctx, kClient)
	defer func() {
		if err := done(); err != nil {
			slog.Error("problem with tailer", "error", err)
		}
	}()
	slog.Info("logger started")

	ollamaClient, err := api.ClientFromEnvironment()
	if err != nil {
		slog.Error("error getting ollama client", "error", err)
	}

	rClient, err := rcon.NewFromEnv()
	if err != nil {
		slog.Error("failed to get rcon client", "error", err)
		return
	}

	// Start goroutines to do the things
	chatRequest := &api.ChatRequest{
		Model:     "qwen3-coder",
		Stream:    proto.Bool(false),
		KeepAlive: &api.Duration{Duration: time.Hour},
		Tools:     api.Tools{},
		Think:     &api.ThinkValue{Value: false},
		Shift:     proto.Bool(true),
		Messages: []api.Message{
			api.Message{
				Role: "system",
				Content: `
		You are Minecraft server admin with a god complex.
		React to any messages from the user by saying something god-like.
		When you join the server, announce yourself.

		Responses should be short; one sentence.
		You may choose to return an empty response if there is nothing interesting to say
		(i.e., no new logs since your last message).

		When a user replies to you, you will see this in the logs:

			2026/02/14 10:48:40 INFO mc log msg="[18:45:10] [Server thread/INFO]: <OrangeYouSad> you are full of it."

		The user here is OrangeYouSad, who said "you are full of it."
		`,
			},
		},
	}
	chat := &chatContext{
		chatRequest: chatRequest,
		maxSize:     10000000,
	}

	doneWg := sync.WaitGroup{}
	doneWg.Go(handleOllama(ctx, ollamaClient, chat, rClient))

	for line := range tailer.NextLine() {
		slog.Info("mc log", "msg", line)
		chat.AddLog(line)
	}

	doneWg.Wait()
}

func handleOllama(ctx context.Context, client *api.Client, chat *chatContext, rClient *rcon.Client) func() {
	slog.Info("got chat request", "object", fmt.Sprintf("%+v", chat.chatRequest))
	return func() {
		var chatResponse api.ChatResponse
		for {
			select {
			case <-ctx.Done():
				return
			case <-time.Tick(time.Second * 10):
				// do nothing
			}
			chat.mu.Lock()
			// slog.Info("sending chat request", "object", fmt.Sprintf("%#v", chat.chatRequest))
			err := client.Chat(ctx, chat.chatRequest, func(cr api.ChatResponse) error {
				chatResponse = cr
				return nil
			})
			chat.mu.Unlock()
			if err != nil {
				slog.Error("error calling ollama", "error", err)
			}
			chat.AddSelf(chatResponse.Message)
			if err := rClient.Say(chatResponse.Message.Content); err != nil {
				slog.Error("error talking", "error", err)
			}
		}
	}
}

func createKubernetesClient() (*kubernetes.Clientset, error) {
	// Try to load in-cluster config first
	config, err := rest.InClusterConfig()
	if err != nil {
		// If in-cluster config fails, try kubeconfig
		loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
		configOverrides := &clientcmd.ConfigOverrides{}
		kubeConfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, configOverrides)
		config, err = kubeConfig.ClientConfig()
		if err != nil {
			return nil, fmt.Errorf("failed to create kubernetes client: %w", err)
		}
	}

	client, err := kubernetes.NewForConfig(config)
	if err != nil {
		return nil, fmt.Errorf("failed to create kubernetes client: %w", err)
	}

	return client, nil
}