[CWS] make sure we do not fetch the hostname multiple times (especially in tests)

pkg/security/utils/hostname.go

@@ -8,6 +8,7 @@ package utils
 
 import (
  "context"
+ "sync"
  "time"
 
  "github.com/avast/retry-go/v4"
@@ -25,15 +26,35 @@ const (
  maxAttempts = 6
 )
 
+var (
+ hostnameLock sync.RWMutex
+ cachedHostname string
+)
+
 // GetHostname attempts to acquire a hostname by connecting to the core
 // agent's gRPC endpoints.
 func GetHostname() (string, error) {
- return GetHostnameWithContext(context.Background())
+ hostnameLock.RLock()
+ if cachedHostname != "" {
+ hostnameLock.RUnlock()
+ return cachedHostname, nil
+ }
+ hostnameLock.RUnlock()
+
+ hostname, err := getHostnameFromAgent(context.Background())
+
+ if hostname != "" {
+ hostnameLock.Lock()
+ cachedHostname = hostname
+ hostnameLock.Unlock()
+ }
+
+ return hostname, err
 }
 
-// GetHostnameWithContext attempts to acquire a hostname by connecting to the
+// getHostnameFromAgent attempts to acquire a hostname by connecting to the
 // core agent's gRPC endpoints extending the given context.
-func GetHostnameWithContext(ctx context.Context) (string, error) {
+func getHostnameFromAgent(ctx context.Context) (string, error) {
  var hostname string
  err := retry.Do(func() error {
  ctx, cancel := context.WithTimeout(ctx, 1*time.Second)
@@ -65,7 +86,7 @@ func GetHostnameWithContext(ctx context.Context) (string, error) {
 // GetHostnameWithContextAndFallback attempts to acquire a hostname by connecting to the
 // core agent's gRPC endpoints extending the given context, or falls back to local resolution
 func GetHostnameWithContextAndFallback(ctx context.Context) (string, error) {
- hostnameDetected, err := GetHostnameWithContext(ctx)
+ hostnameDetected, err := getHostnameFromAgent(ctx)
  if err != nil {
  log.Warnf("Could not resolve hostname from core-agent: %v", err)
  hostnameDetected, err = hostname.Get(ctx)