buildx/util/confutil/node.go

35 lines
708 B
Go

package confutil
import (
"crypto/rand"
"encoding/hex"
"os"
"path/filepath"
"sync"
)
var nodeIdentifierMu sync.Mutex
func TryNodeIdentifier(configDir string) (out string) {
nodeIdentifierMu.Lock()
defer nodeIdentifierMu.Unlock()
sessionFile := filepath.Join(configDir, ".buildNodeID")
if _, err := os.Lstat(sessionFile); err != nil {
if os.IsNotExist(err) { // create a new file with stored randomness
b := make([]byte, 8)
if _, err := rand.Read(b); err != nil {
return out
}
if err := os.WriteFile(sessionFile, []byte(hex.EncodeToString(b)), 0600); err != nil {
return out
}
}
}
dt, err := os.ReadFile(sessionFile)
if err == nil {
return string(dt)
}
return
}