global command

pkg/sys/config.go

@@ -0,0 +1,36 @@
+package sys
+
+import (
+	"log"
+	"sync"
+
+	"novit.nc/direktil/pkg/config"
+)
+
+const cfgPath = "/config.yaml"
+
+var (
+	cfg     *config.Config
+	cfgLock sync.Mutex
+)
+
+func Config() *config.Config {
+	if cfg != nil {
+		return cfg
+	}
+
+	cfgLock.Lock()
+	defer cfgLock.Unlock()
+
+	if cfg != nil {
+		return cfg
+	}
+
+	c, err := config.Load(cfgPath)
+	if err != nil {
+		log.Fatal("FATAL: failed to load config: ", err)
+	}
+
+	cfg = c
+	return cfg
+}

pkg/sys/mount.go

@@ -0,0 +1,19 @@
+package sys
+
+import (
+	"log"
+	"os"
+	"syscall"
+)
+
+func Mount(source, target, fstype string, flags uintptr, data string) {
+	if _, err := os.Stat(target); os.IsNotExist(err) {
+		Mkdir(target, 0755)
+	}
+
+	if err := syscall.Mount(source, target, fstype, flags, data); err != nil {
+		log.Fatalf("FATAL: mount %q %q -t %q -o %q failed: %v", source, target, fstype, data, err)
+	}
+
+	log.Printf("mounted %q", target)
+}

pkg/sys/sys.go

@@ -0,0 +1,87 @@
+package sys
+
+import (
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"time"
+
+	"github.com/fsnotify/fsnotify"
+)
+
+func Run(cmd string, args ...string) (err error) {
+	c := exec.Command(cmd, args...)
+	c.Stdout = os.Stdout
+	c.Stderr = os.Stderr
+
+	if err = c.Run(); err != nil {
+		log.Printf("command %s %q failed: %v", cmd, args, err)
+	}
+	return
+}
+
+func MustRun(cmd string, args ...string) {
+	if err := Run(cmd, args...); err != nil {
+		log.Fatal("FATAL: mandatory command did not succeed")
+	}
+}
+
+func Mkdir(dir string, mode os.FileMode) {
+	if err := os.MkdirAll(dir, mode); err != nil {
+		log.Fatalf("FATAL: mkdir %q failed: %v", dir, err)
+	}
+}
+
+func FileExists(path string) bool {
+	_, err := os.Stat(path)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			log.Printf("WARNING: failed to stat %q, assuming not exist: %v", path, err)
+		}
+		return false
+	}
+	return true
+}
+
+func WaitFile(path string, timeout <-chan time.Time) {
+	if FileExists(path) {
+		return
+	}
+
+	watch, err := fsnotify.NewWatcher()
+	if err != nil {
+		log.Fatal("FATAL: fsnotify: failed to create: ", err)
+	}
+
+	defer watch.Close()
+
+	dir := filepath.Dir(path)
+
+	if err = watch.Add(dir); err != nil {
+		log.Fatalf("FATAL: fsnotify: failed to add %s: %v", dir, err)
+	}
+
+	go func() {
+		for err := range watch.Errors {
+			log.Fatal("FATAL: fsnotify: error: ", err)
+		}
+	}()
+
+	timedOut := false
+	for !timedOut {
+		select {
+		case <-watch.Events:
+			// skip
+
+		case <-timeout:
+			timedOut = true
+		}
+
+		if FileExists(path) {
+			return
+		}
+	}
+
+	log.Fatal("FATAL: timed out waiting for ", path)
+}