fix(Slack): Fixed slack messages when scaler can't to scale more up a…

…nd down (#6)

internal/cmd/run/run.go

@@ -103,8 +103,8 @@ func RunCommand(cmd *cobra.Command, args []string) {
 		// If the up condition is met, add a node to the MIG
 		if upCondition {
 			log.Printf("Up condition %s met: Trying to create a new node!", ctx.Config.Metrics.Prometheus.UpCondition)
-			currentSize, maxSize, err := google.AddNodeToMIG(&ctx)
-			if err != nil {
+			currentSize, maxSize, ok, err := google.AddNodeToMIG(&ctx)
+			if err != nil && !ok {
 				log.Printf("Error adding node to MIG: %v", err)
 				if ctx.Config.Notifications.Slack.WebhookURL != "" {
 					message := fmt.Sprintf("Error adding node to MIG: %v", err)
@@ -117,7 +117,7 @@ func RunCommand(cmd *cobra.Command, args []string) {
 				continue
 			}
 			// Notify via Slack that a node has been added
-			if ctx.Config.Notifications.Slack.WebhookURL != "" {
+			if ctx.Config.Notifications.Slack.WebhookURL != "" && ok {
 				message := fmt.Sprintf("Added new node to MIG %s. Current size is %d nodes and the maximum nodes to create are %d", ctx.Config.Infrastructure.GCP.MIGName, currentSize, maxSize)
 				err = slack.NotifySlack(message, ctx.Config.Notifications.Slack.WebhookURL)
 				if err != nil {
@@ -147,8 +147,8 @@ func RunCommand(cmd *cobra.Command, args []string) {
 		// If the down condition is met, remove a node from the MIG
 		if downCondition {
 			log.Printf("Down condition %s met. Trying to remove one node!", ctx.Config.Metrics.Prometheus.DownCondition)
-			currentSize, minSize, nodeRemoved, err := google.RemoveNodeFromMIG(&ctx)
-			if err != nil {
+			currentSize, minSize, nodeRemoved, ok, err := google.RemoveNodeFromMIG(&ctx)
+			if err != nil && !ok {
 				log.Printf("Error draining node from MIG: %v", err)
 				if ctx.Config.Notifications.Slack.WebhookURL != "" {
 					message := fmt.Sprintf("Error draining node from MIG: %v", err)
@@ -161,7 +161,7 @@ func RunCommand(cmd *cobra.Command, args []string) {
 				continue
 			}
 			// Notify via Slack that a node has been removed
-			if ctx.Config.Notifications.Slack.WebhookURL != "" {
+			if ctx.Config.Notifications.Slack.WebhookURL != "" && ok {
 				message := fmt.Sprintf("Removed node %s from MIG %s. Current size is %d nodes and the minimum nodes to exist are %d", nodeRemoved, ctx.Config.Infrastructure.GCP.MIGName, currentSize, minSize)
 				err = slack.NotifySlack(message, ctx.Config.Notifications.Slack.WebhookURL)
 				if err != nil {

internal/google/mig.go

@@ -20,20 +20,20 @@ import (
 )
 
 // AddNodeToMIG increases the size of the Managed Instance Group (MIG) by 1, if it has not reached the maximum limit.
-func AddNodeToMIG(ctx *v1alpha1.Context) (int32, int32, error) {
+func AddNodeToMIG(ctx *v1alpha1.Context) (int32, int32, bool, error) {
 	ctxConn := context.Background()
 
 	// Create a new Compute client for managing the MIG
 	client, err := createComputeClient(ctxConn, ctx, compute.NewInstanceGroupManagersRESTClient)
 	if err != nil {
-		return 0, 0, fmt.Errorf("failed to create Instance Group Managers client: %v", err)
+		return 0, 0, false, fmt.Errorf("failed to create Instance Group Managers client: %v", err)
 	}
 	defer client.Close()
 
 	// Get the current target size of the MIG
 	targetSize, err := getMIGTargetSize(ctxConn, client, ctx)
 	if err != nil {
-		return 0, 0, fmt.Errorf("failed to get MIG target size: %v", err)
+		return 0, 0, false, fmt.Errorf("failed to get MIG target size: %v", err)
 	}
 	log.Printf("Current size of MIG is %d nodes", targetSize)
 
@@ -42,7 +42,8 @@ func AddNodeToMIG(ctx *v1alpha1.Context) (int32, int32, error) {
 
 	// Check if the MIG has reached its maximum size
 	if targetSize >= maxSize {
-		return 0, 0, fmt.Errorf("MIG has reached its maximum size (%d/%d), no further scaling is possible", targetSize, maxSize)
+		log.Printf("MIG has reached its maximum size (%d/%d), no further scaling is possible", targetSize, maxSize)
+		return 0, 0, true, nil
 	}
 
 	// Create a request to resize the MIG by increasing the target size by 1
@@ -57,29 +58,29 @@ func AddNodeToMIG(ctx *v1alpha1.Context) (int32, int32, error) {
 	if !ctx.Config.Autoscaler.DebugMode {
 		_, err = client.Resize(ctxConn, req)
 		if err != nil {
-			return 0, 0, err
+			return 0, 0, false, err
 		} else {
 			log.Printf("Scaled up MIG successfully %d/%d", targetSize+1, maxSize)
 		}
 	}
-	return targetSize + 1, maxSize, nil
+	return targetSize + 1, maxSize, true, nil
 }
 
 // RemoveNodeFromMIG decreases the size of the Managed Instance Group (MIG) by 1, if it has not reached the minimum limit.
-func RemoveNodeFromMIG(ctx *v1alpha1.Context) (int32, int32, string, error) {
+func RemoveNodeFromMIG(ctx *v1alpha1.Context) (int32, int32, string, bool, error) {
 	ctxConn := context.Background()
 
 	// Create a new Compute client for managing the MIG
 	client, err := createComputeClient(ctxConn, ctx, compute.NewInstanceGroupManagersRESTClient)
 	if err != nil {
-		return 0, 0, "", fmt.Errorf("failed to create Instance Group Managers client: %v", err)
+		return 0, 0, "", false, fmt.Errorf("failed to create Instance Group Managers client: %v", err)
 	}
 	defer client.Close()
 
 	// Get the current target size of the MIG
 	targetSize, err := getMIGTargetSize(ctxConn, client, ctx)
 	if err != nil {
-		return 0, 0, "", fmt.Errorf("failed to get MIG target size: %v", err)
+		return 0, 0, "", false, fmt.Errorf("failed to get MIG target size: %v", err)
 	}
 	log.Printf("Current size of MIG is %d nodes", targetSize)
 
@@ -88,13 +89,14 @@ func RemoveNodeFromMIG(ctx *v1alpha1.Context) (int32, int32, string, error) {
 
 	// Check if the MIG has reached its minimum size
 	if targetSize <= minSize {
-		return 0, 0, "", fmt.Errorf("MIG has reached its minimum size (%d/%d), no further scaling down is possible", targetSize, minSize)
+		log.Printf("MIG has reached its minimum size (%d/%d), no further scaling down is possible", targetSize, minSize)
+		return 0, 0, "", true, nil
 	}
 
 	// Get a random instance from the MIG to remove
 	instanceToRemove, err := GetInstanceToRemove(ctxConn, client, ctx)
 	if err != nil {
-		return 0, 0, "", fmt.Errorf("error getting instance to remove: %v", err)
+		return 0, 0, "", false, fmt.Errorf("error getting instance to remove: %v", err)
 	}
 
 	// If not in debug mode, drain the node from Elasticsearch before removal
@@ -105,7 +107,7 @@ func RemoveNodeFromMIG(ctx *v1alpha1.Context) (int32, int32, string, error) {
 		log.Printf("Instance to remove: %s. Draining from elasticsearch cluster", instanceToRemove)
 		err = elasticsearch.DrainElasticsearchNode(ctx, instanceToRemove)
 		if err != nil {
-			return 0, 0, "", fmt.Errorf("error draining Elasticsearch node: %v", err)
+			return 0, 0, "", false, fmt.Errorf("error draining Elasticsearch node: %v", err)
 		}
 		log.Printf("Instance drained successfully from elasticsearch cluster")
 	}
@@ -125,7 +127,7 @@ func RemoveNodeFromMIG(ctx *v1alpha1.Context) (int32, int32, string, error) {
 	if !ctx.Config.Autoscaler.DebugMode {
 		_, err = client.DeleteInstances(ctxConn, deleteReq)
 		if err != nil {
-			return 0, 0, "", fmt.Errorf("error deleting instance: %v", err)
+			return 0, 0, "", false, fmt.Errorf("error deleting instance: %v", err)
 		}
 	}
 
@@ -144,12 +146,12 @@ func RemoveNodeFromMIG(ctx *v1alpha1.Context) (int32, int32, string, error) {
 		// Remove the elasticsearch node from cluster settings
 		err = elasticsearch.ClearElasticsearchClusterSettings(ctx, instanceToRemove)
 		if err != nil {
-			return 0, 0, "", fmt.Errorf("error clearing Elasticsearch cluster settings: %v", err)
+			return 0, 0, "", false, fmt.Errorf("error clearing Elasticsearch cluster settings: %v", err)
 		}
 		log.Printf("Cleared up elasticsearch settings for draining node")
 	}
 
-	return targetSize - 1, minSize, instanceToRemove, nil
+	return targetSize - 1, minSize, instanceToRemove, true, nil
 }
 
 // getMIGScalingLimits retrieves the minimum and maximum scaling limits for a Managed Instance Group (MIG).