fix: adds cmd/ directory

- It was being ignored due to non-root "slack-bot" being in .gitignore

.gitignore

@@ -18,7 +18,7 @@
 go.work
 
 # executable file
-slack-bot
+/slack-bot
 
 # dot-env files
-*.env
+*.env

cmd/slack-bot/main.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"errors"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+
+	viperpit "github.com/ajpauwels/pit-of-vipers"
+	"github.com/pauwels-labs/slack-bot/internal/config"
+	"github.com/pauwels-labs/slack-bot/pkg/handlers"
+	"github.com/pauwels-labs/slack-bot/pkg/slack"
+	"github.com/spf13/viper"
+	"go.uber.org/zap"
+)
+
+func main() {
+	// Create structured logger
+	logger, err := zap.NewProduction()
+	if err != nil {
+		log.Fatalf("couldn't initialize structured logger: %v", err)
+	}
+	defer logger.Sync()
+
+	// Load env-specific configuration
+	env := os.Getenv("APPCFG_meta_env")
+	configPath := "./config"
+	if len(env) <= 0 {
+		env = "local"
+	}
+	if env != "local" {
+		configPath = "/etc/slack-bot/config"
+	}
+
+	// Create viper instances for base and env-specific config files
+	baseViper := viper.New()
+	baseViper.AddConfigPath(configPath)
+	baseViper.SetConfigName("base")
+	envViper := viper.New()
+	envViper.AddConfigPath(configPath)
+	envViper.SetConfigName(env)
+
+	vpCh, errCh := viperpit.New([]*viper.Viper{baseViper, envViper})
+	for {
+		select {
+		case vp := <-vpCh:
+			// Workaround to add ENV prefix and be able to unmarshal env-provided values
+			vp.SetEnvPrefix("APPCFG")
+			vp.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
+			for _, key := range vp.AllKeys() {
+				val := vp.Get(key)
+				vp.Set(key, val)
+			}
+
+			// Unmarshal config into struct
+			var config config.Config
+			vp.Unmarshal(&config)
+
+			logger.Info("config", zap.Uint16("port", config.Port), zap.String("slack.signingkey", string(config.Slack.SigningKey)))
+
+			// Create the list of supported handlers
+			echoHandler := handlers.NewEchoHandler()
+			handlers := []slack.SlackSlashCommandHandler{echoHandler}
+
+			// Create slack bot server
+			slackBot := slack.NewSlackBot(config.Port, config.Slack.SigningKey, handlers)
+			logger.Info("starting server", zap.Uint16("port", config.Port))
+			err := slackBot.ListenAndServe(logger)
+
+			// Handle normal shutdown and server start errors
+			if errors.Is(err, http.ErrServerClosed) {
+				logger.Info("server has shutdown normally")
+				break
+			} else {
+				logger.Fatal("failed to start http server", zap.Error(err))
+			}
+		case err := <-errCh:
+			logger.Error("error loading config", zap.Error(err))
+		}
+	}
+}