feat(config): add configuration validation CLI

Author: pixel365

Makefile

@@ -1,6 +1,6 @@
-.PHONY: all tidy fa fmt lint vet test pulse pulse-migrate
+.PHONY: all tidy fa fmt lint vet test pulse pulse-migrate pulse-validate
 
-SERVICES = pulse pulse-migrate
+SERVICES = pulse pulse-migrate pulse-validate
 
 all: tidy fa fmt lint
 

README.md

@@ -57,6 +57,12 @@ Example configuration files are available in:
 - `examples/services.yaml`
 - `examples/checks/api-checks.yaml`
 
+Validate configuration with:
+
+```bash
+CONFIG_DIR=./examples go run ./cmd/pulse-validate
+```
+
 Before starting the app, apply migrations:
 
 ```bash

cmd/pulse-migrate/main.go

@@ -20,7 +20,7 @@ var (
 
 func rootCommand(ctx context.Context) *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   "migrate",
+		Use:   "pulse-migrate",
 		Short: "Migrate database",
 		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
 			migrationsDir = os.Getenv("POSTGRES_MIGRATIONS_DIR")

cmd/pulse-validate/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/joho/godotenv"
+	"github.com/spf13/cobra"
+
+	"github.com/pixel365/pulse/internal/config"
+)
+
+func main() {
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	_ = godotenv.Load()
+
+	cmd := &cobra.Command{
+		Use:   "pulse-validate",
+		Short: "Validate configuration",
+		RunE: func(_ *cobra.Command, _ []string) error {
+			_, err := config.Load()
+			return err
+		},
+	}
+
+	if err := cmd.ExecuteContext(ctx); err != nil {
+		os.Exit(1)
+	}
+
+	println("ok")
+}

internal/config/config.go

@@ -21,9 +21,18 @@ type Config struct {
 }
 
 func MustLoad() *Config {
+	cfg, err := Load()
+	if err != nil {
+		panic(err)
+	}
+
+	return cfg
+}
+
+func Load() (*Config, error) {
 	dir := os.Getenv("CONFIG_DIR")
 	if dir == "" {
-		panic("CONFIG_DIR is not set")
+		return nil, fmt.Errorf("CONFIG_DIR is not set")
 	}
 
 	cfg := &Config{
@@ -36,10 +45,10 @@ func MustLoad() *Config {
 		TLSChecks:  make(map[string]TypedCheck[TLSSpec]),
 	}
 	if err := cfg.load(); err != nil {
-		panic(err)
+		return nil, err
 	}
 
-	return cfg
+	return cfg, nil
 }
 
 func (c *Config) load() error {