Fix restart after program has died

This update brings several quality of life enhancements:
- You can now use excluded_files to exclude files from the watcher
- ZQDGR reloads itself when its config changes
- ZQDGR will not start if there are unrecognized keys in the config

It also fixes a bug where if a program was sent a kill signal, but didnt
die, ZQDGR would carry on as if it did, which lead to many issues.

README.md

@@ -14,11 +14,13 @@ go install github.com/juls0730/zqdgr@latest
 ## Usage
 
 Full usage
+
 ```Bash
 zqdgr [options] <command>
 ```
 
-The list of commands is
+### Commands
+
 - `init`
 
   generates a zqdgr.config.json file in the current directory
@@ -30,25 +32,43 @@ The list of commands is
 - `watch <script>`
 
   runs the script in "watch mode", when files that follow the pattern in zqdgr.config.json change, the script restarts
+
 - `<script>`
 
   runs the script
 
+### Options
 
-ZQDGR has the following list of options
 - `-no-ws`
 
   disables the web socket server running at 2067
 
+- `-config`
+
+  specifies the path to the config file
+
+- `-disable-reload-config`
+
+  disables reloading the config file when it changes
+
+- `-C`
+
+  specifies the path to use as the working directry
+
 Example usage:
+
 ```bash
 zqdgr init
 zqdgr watch dev
+zqdgr -config ./my-config.json watch dev
+zqdgr -C ./my-nested-project watch dev
 ```
 
 ### ZQDGR websocket
+
 ZQDGR comes with a websocket to notify listeners that the application has updates, the websocket is accessible at
 `127.0.0.1:2067/ws`. An example dev script to listen for rebuilds might look like this
+
 ```Javascript
 let host = window.location.hostname;
 const socket = new WebSocket('ws://' + host + ':2067/ws');
@@ -75,21 +95,22 @@ socket.addEventListener('message', (event) => {
 
 ZQDGR is solely configured by a `zqdgr.config.json` file in the root of your project. The file has the following keys:
 
-| Key | Type | Description |
-| --- | --- | --- |
-| name | string | The name of the project |
-| version | string | The version of the project |
-| description | string | The description of the project |
-| author | string | The author of the project (probably you) |
-| license | string | The license of the project |
-| homepage | string | The URL to the homepage of the project |
-| repository | object | The repository of the project |
-| repository.type | string | The type of VCS that you use, most likely git |
-| repository.url | string | The place where you code is hosted. This should be a URI that can be used as is in a program such as git |
-| scripts | object | An object that maps a script name to a script command, which is just a shell command |
-| pattern | string | The GLOB pattern that ZQDGR will watch for changes |
-| excluded_dirs | array | The directories that ZQDGR will ignore when in the `watch` mode |
-| shutdown_signal | string | The signal that ZQDGR will use to shutdown the script. Currently the only supported signals are `SIGINT`, `SIGTERM`, and `SIGQUIT`, if no shutdown signal is specified, ZQDGR will default to `SIGKILL` |
+| Key              | Type   | Required | default | Description                                                                                              |
+| ---------------- | ------ | -------- | ------- | -------------------------------------------------------------------------------------------------------- |
+| name             | string | -        | -       | The name of the project                                                                                  |
+| version          | string | -        | -       | The version of the project                                                                               |
+| description      | string | -        | -       | The description of the project                                                                           |
+| author           | string | -        | -       | The author of the project (probably you)                                                                 |
+| license          | string | -        | -       | The license of the project                                                                               |
+| homepage         | string | -        | -       | The URL to the homepage of the project                                                                   |
+| repository       | object | -        | -       | The repository of the project                                                                            |
+| repository.type  | string | -        | -       | The type of VCS that you use, most likely git                                                            |
+| repository.url   | string | -        | -       | The place where you code is hosted. This should be a URI that can be used as is in a program such as git |
+| scripts          | object | true     | -       | An object that maps a script name to a script command, which is just a shell command                     |
+| pattern          | string | true     | -       | The GLOB pattern that ZQDGR will watch for changes                                                       |
+| excluded_globs   | array  | -        | -       | Globs that ZQDGR will ignore when in the `watch` mode                                                    |
+| shutdown_signal  | string | -        | SIGINT  | The signal that ZQDGR will use to shutdown the script. One of SIGKILL, SIGINT, SIGQUIT, SIGTERM          |
+| shutdown_timeout | int    | -        | 1       | The amount of time in seconds that ZQDGR will wait for the script to exit before force killing it.       |
 
 The only required key is `scripts`, the rest are optional, but we recommend you set the most important ones.
 

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bufio"
+	"bytes"
 	_ "embed"
 	"encoding/json"
 	"flag"
@@ -39,8 +40,11 @@ type Config struct {
 	} `json:"repository"`
 	Scripts map[string]string `json:"scripts"`
 	Pattern string            `json:"pattern"`
+	// Deprecated: use excludedGlobs instead
 	ExcludedDirs    []string `json:"excluded_dirs"`
+	ExcludedGlobs   []string `json:"excluded_files"`
 	ShutdownSignal  string   `json:"shutdown_signal"`
+	ShutdownTimeout int      `json:"shutdown_timeout"`
 }
 
 type Script struct {
@@ -72,7 +76,11 @@ func NewZQDGR(enableWebSocket bool, configDir string) *ZQDGR {
 		WorkingDirectory: configDir,
 	}
 
-	zqdgr.loadConfig()
+	err := zqdgr.loadConfig()
+	if err != nil {
+		log.Fatal(err)
+		return nil
+	}
 
 	zqdgr.EnableWebSocket = enableWebSocket
 	zqdgr.WSServer = &WSServer{
@@ -150,10 +158,12 @@ func (s *Script) Start() error {
 				s.exitCode = exitError.ExitCode()
 			} else {
 				// Other errors (e.g., process not found, permission denied)
+				if !s.isRestarting {
 					log.Printf("Error waiting for script %s: %v", s.scriptName, err)
 					s.exitCode = 1
 				}
 			}
+		}
 
 		if !s.isRestarting {
 			s.wg.Done()
@@ -163,8 +173,11 @@ func (s *Script) Start() error {
 	return err
 }
 
-func (s *Script) Restart() error {
+func (s *Script) Stop(lock bool) error {
+	if lock {
 		s.mutex.Lock()
+		defer s.mutex.Unlock()
+	}
 
 	s.isRestarting = true
 
@@ -181,11 +194,51 @@ func (s *Script) Restart() error {
 			signal = syscall.SIGKILL
 		}
 
+		// make sure the process is not dead
+		if s.command.ProcessState != nil && s.command.ProcessState.Exited() {
+			return nil
+		}
+
 		if err := syscall.Kill(-s.command.Process.Pid, signal); err != nil {
 			log.Printf("error killing previous process: %v", err)
+			return err
 		}
 	}
 
+	dead := make(chan bool)
+	go func() {
+		s.command.Wait()
+		dead <- true
+	}()
+
+	shutdownTimeout := s.zqdgr.Config.ShutdownTimeout
+	if shutdownTimeout == 0 {
+		shutdownTimeout = 1
+	}
+
+	select {
+	case <-dead:
+	case <-time.After(time.Duration(shutdownTimeout) * time.Second):
+		log.Println("Script failed to stop after kill signal, force killing")
+
+		if err := syscall.Kill(-s.command.Process.Pid, syscall.SIGKILL); err != nil {
+			log.Printf("error killing previous process: %v", err)
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (s *Script) Restart() error {
+	s.mutex.Lock()
+
+	err := s.Stop(false)
+	if err != nil {
+		s.mutex.Unlock()
+		return err
+	}
+
 	s.command = s.zqdgr.NewCommand(s.scriptName)
 
 	if s.command == nil {
@@ -198,7 +251,7 @@ func (s *Script) Restart() error {
 
 	s.mutex.Unlock()
 
-	err := s.Start()
+	err = s.Start()
 
 	// tell the websocket clients to refresh
 	if s.zqdgr.EnableWebSocket {
@@ -246,7 +299,10 @@ func (wsServer *WSServer) handleWs(w http.ResponseWriter, r *http.Request) {
 func (zqdgr *ZQDGR) loadConfig() error {
 	data, err := os.ReadFile(path.Join(zqdgr.WorkingDirectory, "zqdgr.config.json"))
 	if err == nil {
-		if err := json.Unmarshal(data, &zqdgr.Config); err != nil {
+		decoder := json.NewDecoder(bytes.NewReader(data))
+		decoder.DisallowUnknownFields()
+		err := decoder.Decode(&zqdgr.Config)
+		if err != nil {
 			return fmt.Errorf("error parsing config file: %v", err)
 		}
 	} else {
@@ -259,19 +315,30 @@ func (zqdgr *ZQDGR) loadConfig() error {
 		}
 	}
 
+	if zqdgr.Config.ExcludedDirs != nil {
+		fmt.Printf("WARNING: the 'excluded_dirs' key is deprecated, please use 'excluded_globs' instead\n")
+
+		zqdgr.Config.ExcludedGlobs = append(zqdgr.Config.ExcludedGlobs, zqdgr.Config.ExcludedDirs...)
+	}
+
 	return nil
 }
 
 func main() {
 	noWs := flag.Bool("no-ws", false, "Disable WebSocket server")
 	configDir := flag.String("config", ".", "Path to the config directory")
+	disableReloadConfig := flag.Bool("no-reload-config", false, "Do not restart ZQDGR on config file change")
 	flag.StringVar(configDir, "C", *configDir, "Path to the config directory")
 
 	flag.Parse()
 
+	originalArgs := os.Args
 	os.Args = flag.Args()
 
 	zqdgr := NewZQDGR(*noWs, *configDir)
+	if zqdgr == nil {
+		return
+	}
 
 	var command string
 	var commandArgs []string
@@ -493,6 +560,7 @@ func main() {
 			log.Fatal("watch pattern not specified in config")
 		}
 
+		// make sure the pattern is valid
 		var paternArray []string
 		var currentPattern string
 		inMatch := false
@@ -533,7 +601,7 @@ func main() {
 		}
 
 		watcherConfig := WatcherConfig{
-			excludedDirs: globList(zqdgr.Config.ExcludedDirs),
+			excludedGlobs: globList(zqdgr.Config.ExcludedGlobs),
 			pattern:       paternArray,
 		}
 
@@ -549,6 +617,11 @@ func main() {
 			log.Fatal(err)
 		}
 
+		err = watcher.AddFile(path.Join(zqdgr.WorkingDirectory, "zqdgr.config.json"))
+		if err != nil {
+			log.Fatal(err)
+		}
+
 		// We use this timer to deduplicate events.
 		var (
 			// Wait 100ms for new events; each new event resets the timer.
@@ -573,7 +646,33 @@ func main() {
 					if !ok {
 						timer = time.AfterFunc(waitFor, func() {
 							if event.Op&fsnotify.Remove == fsnotify.Remove || event.Op&fsnotify.Write == fsnotify.Write || event.Op&fsnotify.Create == fsnotify.Create {
+								if os.Getenv("ZQDGR_DEBUG") != "" {
 									fmt.Println("File changed:", event.Name)
+								}
+
+								if strings.HasSuffix(event.Name, "zqdgr.config.json") {
+									// re-exec the exact same command
+									if !*disableReloadConfig {
+										log.Println("zqdgr.config.json has changed, restarting...")
+										executable, err := os.Executable()
+										if err != nil {
+											log.Fatal(err)
+										}
+
+										err = script.Stop(true)
+										if err != nil {
+											log.Fatal(err)
+										}
+
+										err = syscall.Exec(executable, originalArgs, os.Environ())
+										if err != nil {
+											log.Fatal(err)
+										}
+
+										panic("unreachable")
+									}
+								}
+
 								if directoryShouldBeTracked(&watcherConfig, event.Name) {
 									watcher.(NotifyWatcher).watcher.Add(event.Name)
 								}

watcher.go

@@ -4,7 +4,9 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/bmatcuk/doublestar"
 	"github.com/fsnotify/fsnotify"
@@ -14,12 +16,19 @@ type globList []string
 
 func (g *globList) Matches(value string) bool {
 	for _, v := range *g {
+		// if the pattern matches a filepath pattern
 		if match, err := filepath.Match(v, value); err != nil {
 			log.Fatalf("Bad pattern \"%s\": %s", v, err.Error())
 		} else if match {
 			return true
 		}
+
+		// or if the path starts with the pattern
+		if strings.HasSuffix(value, v) {
+			return true
 		}
+	}
+
 	return false
 }
 
@@ -29,12 +38,25 @@ func matchesPattern(pattern []string, path string) bool {
 			return true
 		}
 	}
+
 	return false
 }
 
 func directoryShouldBeTracked(cfg *WatcherConfig, path string) bool {
 	base := filepath.Dir(path)
-	return matchesPattern(cfg.pattern, path) && !cfg.excludedDirs.Matches(base)
+
+	if os.Getenv("ZQDGR_DEBUG") != "" {
+		log.Printf("checking %s against %s %v\n", path, base, *cfg)
+	}
+
+	if cfg.excludedGlobs.Matches(base) {
+		if os.Getenv("ZQDGR_DEBUG") != "" {
+			log.Printf("%s is excluded\n", base)
+		}
+		return false
+	}
+
+	return matchesPattern(cfg.pattern, path)
 }
 
 func pathMatches(cfg *WatcherConfig, path string) bool {
@@ -42,13 +64,14 @@ func pathMatches(cfg *WatcherConfig, path string) bool {
 }
 
 type WatcherConfig struct {
-	excludedDirs globList
+	excludedGlobs globList
 	pattern       globList
 }
 
 type FileWatcher interface {
 	Close() error
 	AddFiles() error
+	AddFile(path string) error
 	add(path string) error
 	getConfig() *WatcherConfig
 }
@@ -62,6 +85,14 @@ func (n NotifyWatcher) Close() error {
 	return n.watcher.Close()
 }
 
+func (n NotifyWatcher) AddFile(path string) error {
+	if os.Getenv("ZQDGR_DEBUG") != "" {
+		log.Printf("manually adding file\n")
+	}
+
+	return n.add(path)
+}
+
 func (n NotifyWatcher) AddFiles() error {
 	return addFiles(n)
 }
@@ -79,10 +110,12 @@ func NewWatcher(cfg *WatcherConfig) (FileWatcher, error) {
 		err := errors.New("no config specified")
 		return nil, err
 	}
+
 	w, err := fsnotify.NewWatcher()
 	if err != nil {
 		return nil, err
 	}
+
 	return NotifyWatcher{
 		watcher: w,
 		cfg:     cfg,
@@ -92,18 +125,31 @@ func NewWatcher(cfg *WatcherConfig) (FileWatcher, error) {
 func addFiles(fw FileWatcher) error {
 	cfg := fw.getConfig()
 	for _, pattern := range cfg.pattern {
+		if os.Getenv("ZQDGR_DEBUG") != "" {
+			fmt.Printf("processing glob %s\n", pattern)
+		}
+
 		matches, err := doublestar.Glob(pattern)
 		if err != nil {
 			log.Fatalf("Bad pattern \"%s\": %s", pattern, err.Error())
 		}
+
 		for _, match := range matches {
+			if os.Getenv("ZQDGR_DEBUG") != "" {
+				log.Printf("checking %s\n", match)
+			}
+
 			if directoryShouldBeTracked(cfg, match) {
+				if os.Getenv("ZQDGR_DEBUG") != "" {
+					log.Printf("%s is not excluded\n", match)
+				}
+
 				if err := fw.add(match); err != nil {
 					return fmt.Errorf("FileWatcher.Add(): %v", err)
 				}
 			}
 		}
-
 	}
+
 	return nil
 }

zqdgr.config.json

@@ -1,6 +1,6 @@
 {
     "name": "zqdgr",
-    "version": "0.0.3",
+    "version": "0.0.4a",
     "description": "zqdgr is a quick and dirty Golang runner",
     "author": "juls0730",
     "license": "BSL-1.0",