Extracted tap config to consistent volume (#617)

agent/pkg/controllers/config_controller.go

@@ -11,18 +11,18 @@ import (
 	"mizuserver/pkg/config"
 	"mizuserver/pkg/models"
 	"mizuserver/pkg/providers"
+	"mizuserver/pkg/providers/tapConfig"
 	"net/http"
 	"regexp"
 	"time"
 )
 
-var globalTapConfig = &models.TapConfig{TappedNamespaces: make(map[string]bool)}
 var cancelTapperSyncer context.CancelFunc
 
 func PostTapConfig(c *gin.Context) {
-	tapConfig := &models.TapConfig{}
+	requestTapConfig := &models.TapConfig{}
 
-	if err := c.Bind(tapConfig); err != nil {
+	if err := c.Bind(requestTapConfig); err != nil {
 		c.JSON(http.StatusBadRequest, err)
 		return
 	}
@@ -37,7 +37,7 @@ func PostTapConfig(c *gin.Context) {
 	}
 
 	var tappedNamespaces []string
-	for namespace, tapped := range tapConfig.TappedNamespaces {
+	for namespace, tapped := range requestTapConfig.TappedNamespaces {
 		if tapped {
 			tappedNamespaces = append(tappedNamespaces, namespace)
 		}
@@ -60,7 +60,7 @@ func PostTapConfig(c *gin.Context) {
 	}
 
 	cancelTapperSyncer = cancel
-	globalTapConfig = tapConfig
+	tapConfig.Save(requestTapConfig)
 
 	c.JSON(http.StatusOK, "OK")
 }
@@ -81,17 +81,19 @@ func GetTapConfig(c *gin.Context) {
 		return
 	}
 
+	savedTapConfig := tapConfig.Get()
+
 	tappedNamespaces := make(map[string]bool)
 	for _, namespace := range namespaces {
 		if namespace.Name == config.Config.MizuResourcesNamespace {
 			continue
 		}
 
-		tappedNamespaces[namespace.Name] = globalTapConfig.TappedNamespaces[namespace.Name]
+		tappedNamespaces[namespace.Name] = savedTapConfig.TappedNamespaces[namespace.Name]
 	}
 
-	tapConfig := models.TapConfig{TappedNamespaces: tappedNamespaces}
+	tapConfigToReturn := models.TapConfig{TappedNamespaces: tappedNamespaces}
-	c.JSON(http.StatusOK, tapConfig)
+	c.JSON(http.StatusOK, tapConfigToReturn)
 }
 
 func startMizuTapperSyncer(ctx context.Context, provider *kubernetes.Provider, targetNamespaces []string, podFilterRegex regexp.Regexp, ignoredUserAgents []string, mizuApiFilteringOptions tapApi.TrafficFilteringOptions, serviceMesh bool) (*kubernetes.MizuTapperSyncer, error) {

agent/pkg/providers/tapConfig/tap_config_provider.go

@@ -0,0 +1,54 @@
+package tapConfig
+
+import (
+	"encoding/json"
+	"github.com/up9inc/mizu/shared"
+	"github.com/up9inc/mizu/shared/logger"
+	"io/ioutil"
+	"mizuserver/pkg/models"
+	"os"
+	"sync"
+)
+
+const FilePath = shared.DataDirPath + "tap-config.json"
+
+var lock = &sync.Mutex{}
+
+var config *models.TapConfig
+
+func Get() *models.TapConfig {
+	if config == nil {
+		lock.Lock()
+		defer lock.Unlock()
+
+		if config == nil {
+			if content, err := ioutil.ReadFile(FilePath); err != nil {
+				config = &models.TapConfig{TappedNamespaces: make(map[string]bool)}
+				if !os.IsNotExist(err) {
+					logger.Log.Errorf("Error loading tap config from file, err: %v", err)
+				}
+			} else {
+				if err = json.Unmarshal(content, &config); err != nil {
+					config = &models.TapConfig{TappedNamespaces: make(map[string]bool)}
+					logger.Log.Errorf("Error while unmarshal tap config, err: %v", err)
+				}
+			}
+		}
+	}
+
+	return config
+}
+
+func Save(tapConfigToSave *models.TapConfig) {
+	lock.Lock()
+	defer lock.Unlock()
+
+	config = tapConfigToSave
+	if data, err := json.Marshal(config); err != nil {
+		logger.Log.Errorf("Error while marshal tap config, err: %v", err)
+	} else {
+		if err := ioutil.WriteFile(FilePath, data, 0644); err != nil {
+			logger.Log.Errorf("Error writing tap config to file, err: %v", err)
+		}
+	}
+}