feat: Improve error handling (#156)

- Make cmd's return `*errors.WakuError`
- Fixup some logging
- Have `Print` operations respect `log.LogLevel`

---------

Closes #155
Signed-off-by: AlexNg <contact@ngjx.org>

cmd/cleanup/cleanup.go

@@ -0,0 +1,81 @@
+// For async cleanup in cases of interrupts
+package cleanup
+
+import (
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	"github.com/caffeine-addictt/waku/internal/log"
+)
+
+var (
+	cleanupStack      []func() error
+	cleanupRwLock     sync.RWMutex
+	errorCleanupStack []func() error
+	errorRwLock       sync.RWMutex
+)
+
+// Schedule adds a function to the cleanup stack
+//
+// Cleanups are ran no matter what, before error cleanup
+func Schedule(fn func() error) {
+	cleanupRwLock.Lock()
+	defer cleanupRwLock.Unlock()
+	cleanupStack = append(cleanupStack, fn)
+}
+
+// ScheduleError adds a function to the error cleanup stack
+//
+// Error cleanups are ran ONLY when an error occurs, and
+// are ran after all regular cleanups
+func ScheduleError(fn func() error) {
+	errorRwLock.Lock()
+	defer errorRwLock.Unlock()
+	errorCleanupStack = append(errorCleanupStack, fn)
+}
+
+// Runs all cleanup functions
+func Cleanup() {
+	cleanupRwLock.Lock()
+	defer cleanupRwLock.Unlock()
+
+	log.Debugf("cleaning up %d items...\n", len(cleanupStack))
+	for i := len(cleanupStack) - 1; i >= 0; i-- {
+		if err := cleanupStack[i](); err != nil {
+			log.Errorf("error while cleaning up: %v\n", err)
+		}
+	}
+
+	cleanupStack = []func() error{}
+}
+
+// Runs all error cleanup functions
+func CleanupError() {
+	errorRwLock.Lock()
+	defer errorRwLock.Unlock()
+
+	log.Debugf("cleaning up %d items due to error...\n", len(errorCleanupStack))
+	for i := len(errorCleanupStack) - 1; i >= 0; i-- {
+		if err := errorCleanupStack[i](); err != nil {
+			log.Errorf("error while cleaning up: %v\n", err)
+		}
+	}
+
+	errorCleanupStack = []func() error{}
+}
+
+// Watches for interrupts and runs all cleanup functions.
+func On() {
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+
+	go func() {
+		sig := <-sigs
+		log.Printf("%v received, cleaning up...\n", sig)
+
+		Cleanup()
+		CleanupError()
+	}()
+}

cmd/commands/check.go

@@ -1,10 +1,11 @@
 package commands
 
 import (
-	"os"
 	"path/filepath"
 	"strings"
 
+	"github.com/caffeine-addictt/waku/internal/errors"
+	"github.com/caffeine-addictt/waku/internal/log"
 	"github.com/caffeine-addictt/waku/internal/template"
 	"github.com/caffeine-addictt/waku/internal/utils"
 	"github.com/spf13/cobra"
@@ -18,11 +19,10 @@ var CheckCmd = &cobra.Command{
 	Args:          cobra.MaximumNArgs(1),
 	SilenceErrors: true,
 	SilenceUsage:  true,
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		// Check for naming
 		if len(args) == 1 && !strings.HasSuffix(args[0], "template.json") {
-			cmd.PrintErrln("name your file template.json")
-			os.Exit(1)
+			return errors.NewWakuErrorf("name your file template.json")
 		}
 
 		// Resolve file path
@@ -34,21 +34,21 @@ var CheckCmd = &cobra.Command{
 		}
 		filePath = filepath.Clean(filePath)
 
+		log.Debugf("checking if %s is a file\n", filePath)
 		ok, err := utils.IsFile(filePath)
 		if err != nil {
-			cmd.PrintErrln(err)
-			os.Exit(1)
+			return errors.NewWakuErrorf("failed to check if %s is a file: %v", filePath, err)
 		}
 		if !ok {
-			cmd.PrintErrln("template.json not found")
-			os.Exit(1)
+			return errors.NewWakuErrorf("%s does not exist or is not a file", filePath)
 		}
 
+		log.Debugf("checking if %s is a valid template\n", filePath)
 		if _, err := template.ParseConfig(filePath); err != nil {
-			cmd.PrintErrln(err)
-			os.Exit(1)
+			return errors.ToWakuError(err)
 		}
 
-		cmd.Println("Seems ok!")
+		log.Println("Seems ok!")
+		return nil
 	},
 }

cmd/commands/healthcheck.go

@@ -1,6 +1,7 @@
 package commands
 
 import (
+	"github.com/caffeine-addictt/waku/internal/errors"
 	"github.com/caffeine-addictt/waku/internal/git"
 	"github.com/caffeine-addictt/waku/internal/log"
 	"github.com/spf13/cobra"
@@ -15,7 +16,7 @@ var HealthcheckCmd = &cobra.Command{
 	RunE: func(cmd *cobra.Command, args []string) error {
 		ok, err := git.HasGit()
 		if err != nil {
-			return err
+			return errors.ToWakuError(err)
 		}
 
 		if !ok {