api: Change Extract and CheckIn to include config-changed

app/api.go

@@ -21,16 +21,17 @@ func NewAppWithConfig(sota *sotatoml.AppConfig, secretsDir string, unsafeHandler
 
 // Extract extracts secrets from the encrypted configuration into the secrets directory.
 // must be called once. A common way to do this is a systemd "oneshot" service after
-// NetworkManager is up.
-func (a *App) Extract() error {
+// NetworkManager is up. It returns true if a config change was detected.
+func (a *App) Extract() (bool, error) {
 	return (*internal.App)(a).Extract()
 }
 
 // CheckIn checks with the device gateway for the lastest configuration. If there
 // are changes, it applies them locally. If the config on the server is unchanged,
 // it returns NotModifiedError. This function also will try and run any pending
 // "init" functions required by Fioconfig that have not yet been run.
-func (a *App) CheckIn() error {
+// It returns true if a config change was detected.
+func (a *App) CheckIn() (bool, error) {
 	return (*internal.App)(a).CheckIn()
 }
 

internal/app.go

@@ -107,10 +107,11 @@ func updateSecret(secretFile string, newContent []byte) (bool, error) {
 	return true, sotatoml.SafeWrite(secretFile, newContent)
 }
 
-func (a *App) extract(config configSnapshot) error {
+func (a *App) extract(config configSnapshot) (bool, error) {
+	configChanged := false
 	st, err := os.Stat(a.SecretsDir)
 	if err != nil {
-		return err
+		return configChanged, err
 	}
 
 	all_fname := make(map[string]bool)
@@ -120,45 +121,47 @@ func (a *App) extract(config configSnapshot) error {
 		fullpath := filepath.Join(a.SecretsDir, fname)
 		dirName := filepath.Dir(fullpath)
 		if err := os.MkdirAll(dirName, st.Mode()); err != nil {
-			return fmt.Errorf("Unable to create parent directory secret: %s - %w", fullpath, err)
+			return configChanged, fmt.Errorf("Unable to create parent directory secret: %s - %w", fullpath, err)
 		}
 		changed, err := updateSecret(fullpath, []byte(cfgFile.Value))
 		if err != nil {
-			return err
+			return configChanged, err
 		}
 		if changed {
+			configChanged = true
 			a.runOnChanged(fname, fullpath, cfgFile.OnChanged)
 		}
 	}
 
 	// Now, watch for file removals (compare with a previous version if present)
 	if config.prev == nil {
-		return nil
+		return configChanged, nil
 	}
 	for fname, cfgFile := range config.prev {
 		if _, ok := all_fname[fname]; ok {
 			continue
 		}
 		slog.Info("Removing file", "file", fname)
+		configChanged = true
 		fullpath := filepath.Join(a.SecretsDir, fname)
 		if err := os.Remove(fullpath); err != nil && !os.IsNotExist(err) {
-			return err
+			return configChanged, err
 		}
 		a.runOnChanged(fname, fullpath, cfgFile.OnChanged)
 	}
 	if err := DeleteEmptyDirs(a.SecretsDir); err != nil {
 		slog.Error("Unable to remove empty directories", "error", err)
 	}
-	return nil
+	return configChanged, nil
 }
 
-func (a *App) Extract() error {
+func (a *App) Extract() (bool, error) {
 	_, crypto := createClient(a.sota)
 	defer crypto.Close()
 
 	config, err := UnmarshallFile(crypto, a.EncryptedConfig, true)
 	if err != nil {
-		return err
+		return false, err
 	}
 	return a.extract(configSnapshot{nil, config})
 }
@@ -192,10 +195,9 @@ func (a *App) runOnChanged(fname string, fullpath string, onChanged []string) {
 	}
 }
 
-func (a *App) checkin(client *http.Client, crypto CryptoHandler) error {
+func (a *App) checkin(client *http.Client, crypto CryptoHandler) (configChanged bool, err error) {
 	headers := make(map[string]string)
 	var config configSnapshot
-	var err error
 
 	if config.prev, err = UnmarshallFile(nil, a.EncryptedConfig, false); err != nil {
 		var perr *os.PathError
@@ -210,41 +212,45 @@ func (a *App) checkin(client *http.Client, crypto CryptoHandler) error {
 
 	res, err := transport.HttpGet(client, a.configUrl, headers)
 	if err != nil {
-		return err // Unable to attempt request
+		return // Unable to attempt request
 	}
 
 	if res.StatusCode == 200 {
 		if config.next, err = UnmarshallBuffer(crypto, res.Body, true); err != nil {
-			return err
+			return
 		}
 
-		if err = a.extract(config); err != nil {
-			return err
+		if configChanged, err = a.extract(config); err != nil {
+			return
 		}
 		if err = sotatoml.SafeWrite(a.EncryptedConfig, res.Body); err != nil {
-			return err
+			return
 		}
 
-		modtime, err := time.Parse(time.RFC1123, res.Header.Get("Date"))
-		if err != nil {
-			slog.Warn("Unable to get modtime of config file, defaulting to 'now'", "error", err)
+		modtime, err2 := time.Parse(time.RFC1123, res.Header.Get("Date"))
+		if err2 != nil {
+			slog.Warn("Unable to get modtime of config file, defaulting to 'now'", "error", err2)
 			modtime = time.Now()
 		}
 		if err = os.Chtimes(a.EncryptedConfig, modtime, modtime); err != nil {
-			return fmt.Errorf("Unable to set modified time %s - %w", a.EncryptedConfig, err)
+			err = fmt.Errorf("Unable to set modified time %s - %w", a.EncryptedConfig, err)
+			return
 		}
-		return nil
+		return
 	} else if res.StatusCode == 304 {
 		slog.Info("Config on server has not changed")
-		return NotModifiedError
+		err = NotModifiedError
+		return
 	} else if res.StatusCode == 204 {
 		slog.Info("Device has no config defined on server")
-		return NotModifiedError
+		err = NotModifiedError
+		return
 	}
-	return fmt.Errorf("Unable to get %s - HTTP_%d: %s", a.configUrl, res.StatusCode, res.String())
+	err = fmt.Errorf("Unable to get %s - HTTP_%d: %s", a.configUrl, res.StatusCode, res.String())
+	return
 }
 
-func (a *App) CheckIn() error {
+func (a *App) CheckIn() (bool, error) {
 	client, crypto := createClient(a.sota)
 	defer crypto.Close()
 	callInitFunctions(a, client)

internal/app_test.go

@@ -197,7 +197,7 @@ func assertNoFile(t *testing.T, path string) {
 
 func TestExtract(t *testing.T) {
 	testWrapper(t, nil, func(app *App, client *http.Client, tempdir string) {
-		if err := app.Extract(); err != nil {
+		if _, err := app.Extract(); err != nil {
 			t.Fatal(err)
 		}
 
@@ -210,7 +210,7 @@ func TestExtract(t *testing.T) {
 
 		// Make sure files that don't change aren't updated
 		os.Remove(barChanged)
-		if err := app.Extract(); err != nil {
+		if _, err := app.Extract(); err != nil {
 			t.Fatal(err)
 		}
 		_, err := os.Stat(barChanged)
@@ -223,8 +223,10 @@ func TestExtract(t *testing.T) {
 func TestSafeHandler(t *testing.T) {
 	testWrapper(t, nil, func(app *App, client *http.Client, tempdir string) {
 		app.unsafeHandlers = false
-		if err := app.Extract(); err != nil {
+		if changed, err := app.Extract(); err != nil {
 			t.Fatal(err)
+		} else if !changed {
+			t.Fatal("Config change not detected")
 		}
 		barChanged := filepath.Join(tempdir, "bar-changed")
 		_, err := os.Stat(barChanged)
@@ -257,7 +259,9 @@ func TestHandlerExit(t *testing.T) {
 		buf, err = json.Marshal(config)
 		require.Nil(t, err)
 		require.Nil(t, os.WriteFile(app.EncryptedConfig, buf, 0o777))
-		require.Nil(t, app.Extract())
+		changed, err := app.Extract()
+		require.Nil(t, err)
+		require.True(t, changed)
 		require.True(t, called)
 	})
 }
@@ -270,10 +274,11 @@ func TestCheckBad(t *testing.T) {
 	testWrapper(t, doGet, func(app *App, client *http.Client, tempdir string) {
 		_, crypto := createClient(app.sota)
 		defer crypto.Close()
-		err := app.checkin(client, crypto)
+		changed, err := app.checkin(client, crypto)
 		if err == nil {
 			t.Fatal("Checkin should have gotten a 404")
 		}
+		require.False(t, changed)
 
 		if !strings.HasSuffix(strings.TrimSpace(err.Error()), "HTTP_404: 404 page not found") {
 			t.Fatalf("Unexpected response: '%s'", err)
@@ -306,7 +311,7 @@ func TestCheckCorruptedConfig(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		if err := app.checkin(client, crypto); err != nil {
+		if _, err := app.checkin(client, crypto); err != nil {
 			t.Fatal(err)
 		}
 
@@ -351,8 +356,10 @@ func TestCheckGood(t *testing.T) {
 		// Remove this file so we can be sure the check-in creates it
 		os.Remove(app.EncryptedConfig)
 
-		if err := app.checkin(client, crypto); err != nil {
+		if changed, err := app.checkin(client, crypto); err != nil {
 			t.Fatal(err)
+		} else if !changed {
+			t.Fatal("Config-change not detected")
 		}
 
 		foo := filepath.Join(tempdir, "foo")
@@ -380,13 +387,13 @@ func TestCheckGood(t *testing.T) {
 		time.Sleep(1 * time.Millisecond)
 
 		// Now make sure the if-not-modified logic works
-		if err := app.checkin(client, crypto); err != NotModifiedError {
+		if _, err := app.checkin(client, crypto); err != NotModifiedError {
 			t.Fatal(err)
 		}
 
 		// Check that files removed on server are also removed on device and onChange is called
 		removeBar = true
-		if err := app.checkin(client, crypto); err != nil {
+		if _, err := app.checkin(client, crypto); err != nil {
 			t.Fatal(err)
 		}
 

main.go

@@ -59,7 +59,7 @@ func extract(c *cli.Context) error {
 		}
 	}
 	slog.Info("Extracting keys", "from", app.EncryptedConfig, "to", app.SecretsDir)
-	if err := app.Extract(); err != nil {
+	if _, err := app.Extract(); err != nil {
 		if errors.Is(err, os.ErrNotExist) {
 			slog.Info("Encrypted config does not exist")
 		} else {
@@ -76,7 +76,7 @@ func checkin(c *cli.Context) error {
 	}
 
 	slog.Info("Checking in with server ...")
-	if err := app.CheckIn(); err != nil && !errors.Is(err, internal.NotModifiedError) {
+	if _, err := app.CheckIn(); err != nil && !errors.Is(err, internal.NotModifiedError) {
 		return err
 	}
 	return nil
@@ -91,7 +91,7 @@ func daemon(c *cli.Context) error {
 	slog.Info("Running as daemon", "interval", c.Int("interval"))
 	for {
 		slog.Info("Checking in with server")
-		if err := app.CheckIn(); err != nil && !errors.Is(err, internal.NotModifiedError) {
+		if _, err := app.CheckIn(); err != nil && !errors.Is(err, internal.NotModifiedError) {
 			slog.Error("Check-in failed", "error", err)
 		}
 		time.Sleep(interval)