Galus - Live Reloading for Go Applications

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Galus is a live reloading tool for Go applications, similar to Air or CompileDaemon. It monitors file changes in your project, automatically recompiles, and restarts the application.

Features

• Live Reloading: Automatically detects changes in specified file types (e.g., .go) and recompiles and restarts the application.

• Configurable via .galus.toml: Customize watched directories, file extensions, build commands, and runtime arguments using a TOML configuration file.

• Colorful CLI Output: Provides clear, color-coded output for better user experience (e.g., green for success, red for errors).

• Rich CLI Commands: Supports init to create a default configuration file, version to display the app version, and help for command usage details.

• Graceful Shutdown: Uses SIGTERM to safely stop running processes, with a fallback to force termination if needed. The grace period is configurable via kill_grace.

• Resilient Reloads: A failed build never kills the currently running binary — the last working version keeps serving until a build succeeds.

• Debounced File Events: Bursts of file changes (e.g. saving many files at once) are combined into a single rebuild via a configurable debounce window, instead of rebuilding once per event.

• Full File Event Coverage: Responds to file create, write, remove, and rename events, not just writes.

• Hooks (pre_cmd / post_cmd): Run commands before building (e.g. go vet, go generate) and after the app restarts. A failing pre_cmd aborts the rebuild and keeps the current process running.

• Environment Variables: Inject env vars into both the build command and the running process via the env config option.

• Polling Fallback: When polling = true, Galus periodically scans the project for changes instead of relying solely on filesystem events — useful for editors or Docker bind-mounts that don't emit fsnotify events reliably.

• Configuration Validation: Ensures build_cmd and command_args are valid before starting the live reload process.

• Cross-Platform: Works on any platform supported by Go, with easy installation via go get.

Installation

1. Install galus using go get:

   go get github.com/aliftech/galus

2. Install the binary to make galus available globally:

   go install github.com/aliftech/galus

3. Ensure $GOPATH/bin is in your $PATH:

   export PATH=$PATH:$(go env GOPATH)/bin

Usage

1. Initialize a configuration file: In your project directory, run:

   galus init

   This creates a .galus.toml configuration file with default setting.

2. Start live reloading: In your project directory, run:

   galus

   Galus will monitor file changes (e.g., .go files), recompile, and restart your application.

Configuration

The .galus.toml file allows you to customize Galus behavior. Example configuration:

root_dir = "."tmp_dir = "tmp"include_ext = ["go"]
exclude_dir = [".git", "vendor", "tmp"]
build_cmd = "go build -o ./tmp/main ."binary_name = "tmp/main"command_args = ["tmp/main"]
kill_grace = "5s"debounce = "300ms"pre_cmd = []
post_cmd = []
env = {}
polling = falsepolling_interval = "500ms"

• root_dir: Directory to monitor for changes.
• tmp_dir: Temporary directory for compiled binaries.
• include_ext: File extensions to monitor (e.g., ["go", "html"]).
• exclude_dir: Directories to ignore.
• build_cmd: Command to compile the application.
• binary_name: Name of the compiled binary.
• command_args: Arguments to run the binary.
• kill_grace: How long to wait for the running process to stop gracefully (via SIGTERM) before force-killing it.
• debounce: How long to wait after the last file change before rebuilding, combining bursts of events into a single rebuild.
• pre_cmd: Commands to run before each build (e.g. ["go vet ./...", "go generate ./..."]). If any fails, the rebuild is aborted and the current process keeps running.
• post_cmd: Commands to run after the app restarts (e.g. ["go run ./cmd/gen"]). Failures are logged but do not stop the app.
• env: Environment variables applied to both the build and the running process (e.g. { PORT = "8080", DEBUG = "true" }).
• polling: Set to true to scan the project periodically instead of relying solely on filesystem events.
• polling_interval: How often to scan for changes when polling is enabled.