Refactor EncryptedDiskStore to return io.Reader instead of io.ReadCloser

internal/pkg/agent/application/info/agent_id.go

@@ -37,7 +37,7 @@ type persistentAgentInfo struct {
 
 type ioStore interface {
 	Save(io.Reader) error
-	Load() (io.ReadCloser, error)
+	Load() (io.Reader, error)
 }
 
 // updateLogLevel updates log level and persists it to disk.

internal/pkg/agent/storage/disk_store.go

@@ -97,7 +97,7 @@ func (d *DiskStore) Save(in io.Reader) error {
 }
 
 // Load return a io.ReadCloser for the target file.
-func (d *DiskStore) Load() (io.ReadCloser, error) {
+func (d *DiskStore) Load() (io.Reader, error) {
 	fd, err := os.OpenFile(d.target, os.O_RDONLY|os.O_CREATE, perms)
 	if err != nil {
 		return nil, errors.New(err,

internal/pkg/agent/storage/encrypted_disk_storage_windows_linux_test.go

@@ -41,7 +41,6 @@ func TestEncryptedDiskStorageWindowsLinuxLoad(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer r.Close()
 
 	b, err := io.ReadAll(r)
 	if err != nil {
@@ -98,7 +97,6 @@ func TestEncryptedDiskStorageWindowsLinuxLoad(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer nr.Close()
 
 	b, err = io.ReadAll(nr)
 	if err != nil {

internal/pkg/agent/storage/encrypted_disk_store.go

@@ -167,31 +167,25 @@ func (d *EncryptedDiskStore) Save(in io.Reader) error {
 }
 
 // Load returns an io.ReadCloser for the target.
-func (d *EncryptedDiskStore) Load() (rc io.ReadCloser, err error) {
-	fd, err := os.OpenFile(d.target, os.O_RDONLY, perms)
+func (d *EncryptedDiskStore) Load() (rc io.Reader, err error) {
+	data, err := os.ReadFile(d.target)
 	if err != nil {
 		if errors.Is(err, os.ErrNotExist) {
 			// If file doesn't exist, return empty reader closer
-			return io.NopCloser(bytes.NewReader([]byte{})), nil
+			return bytes.NewReader([]byte{}), nil
 		}
 		return nil, errors.New(err,
 			fmt.Sprintf("could not open %s", d.target),
 			errors.TypeFilesystem,
 			errors.M(errors.MetaKeyPath, d.target))
 	}
 
-	// Close fd if there is an error upon return
-	defer func() {
-		if err != nil && fd != nil {
-			_ = fd.Close()
-		}
-	}()
-
 	// Ensure has agent key
 	err = d.ensureKey(d.ctx)
 	if err != nil {
-		return nil, errors.New(err, "failed to ensure key during encrypted disk store Load")
+		return nil, errors.New(err,
+			"failed to ensure key during encrypted disk store Load")
 	}
 
-	return crypto.NewReaderWithDefaults(fd, d.key)
+	return crypto.NewReaderWithDefaults(bytes.NewReader(data), d.key)
 }

internal/pkg/agent/storage/storage.go

@@ -23,7 +23,7 @@ type Storage interface {
 	Store
 
 	// Load return an io.ReadCloser for the target store.
-	Load() (io.ReadCloser, error)
+	Load() (io.Reader, error)
 
 	// Exists checks if the store exists.
 	Exists() (bool, error)

internal/pkg/agent/storage/storage_test.go

@@ -184,7 +184,6 @@ func TestDiskStore(t *testing.T) {
 		d := NewDiskStore(target)
 		r, err := d.Load()
 		require.NoError(t, err)
-		defer r.Close()
 
 		content, err := io.ReadAll(r)
 		require.NoError(t, err)

internal/pkg/agent/storage/store/state_store.go

@@ -27,7 +27,7 @@ type store interface {
 
 type storeLoad interface {
 	store
-	Load() (io.ReadCloser, error)
+	Load() (io.Reader, error)
 }
 
 type action = fleetapi.Action