Break notify into submethods to create the session then create the publish input to send. Check we populate a region for all requests.

This reverts commit 4c2a5f1.

Signed-off-by: Tyler Reid <[email protected]>

Author: Tyler Reid

notify/sns/sns.go

@@ -62,20 +62,45 @@ func New(c *config.SNSConfig, t *template.Template, l log.Logger, httpOpts ...co
 
 func (n *Notifier) Notify(ctx context.Context, alert ...*types.Alert) (bool, error) {
 	var (
-		err   error
-		data                           = notify.GetTemplateData(ctx, n.tmpl, alert, n.logger)
-		tmpl                           = notify.TmplText(n.tmpl, data, &err)
-		creds *credentials.Credentials = nil
+		err  error
+		data = notify.GetTemplateData(ctx, n.tmpl, alert, n.logger)
+		tmpl = notify.TmplText(n.tmpl, data, &err)
 	)
-	if n.conf.Sigv4.AccessKey != "" && n.conf.Sigv4.SecretKey != "" {
-		creds = credentials.NewStaticCredentials(n.conf.Sigv4.AccessKey, string(n.conf.Sigv4.SecretKey), "")
+
+	client, err := createSNSClient(n, tmpl)
+	if err != nil {
+		if e, ok := err.(awserr.RequestFailure); ok {
+			return n.retrier.Check(e.StatusCode(), strings.NewReader(e.Message()))
+		} else {
+			return true, err
+		}
 	}
 
-	attributes := make(map[string]*sns.MessageAttributeValue, len(n.conf.Attributes))
-	for k, v := range n.conf.Attributes {
-		attributes[tmpl(k)] = &sns.MessageAttributeValue{DataType: aws.String("String"), StringValue: aws.String(tmpl(v))}
+	publishInput, err := createPublishInput(ctx, n, tmpl)
+	if err != nil {
+		return true, err
+	}
+
+	publishOutput, err := client.Publish(publishInput)
+	if err != nil {
+		if e, ok := err.(awserr.RequestFailure); ok {
+			return n.retrier.Check(e.StatusCode(), strings.NewReader(e.Message()))
+		} else {
+			return true, err
+		}
 	}
 
+	level.Debug(n.logger).Log("msg", "SNS message successfully published", "message_id", publishOutput.MessageId, "sequence number", publishOutput.SequenceNumber)
+
+	return false, nil
+}
+
+func createSNSClient(n *Notifier, tmpl func(string) string) (*sns.SNS, error) {
+	var creds *credentials.Credentials = nil
+	// If there are provided sigV4 credentials we want to use those to create a session.
+	if n.conf.Sigv4.AccessKey != "" && n.conf.Sigv4.SecretKey != "" {
+		creds = credentials.NewStaticCredentials(n.conf.Sigv4.AccessKey, string(n.conf.Sigv4.SecretKey), "")
+	}
 	sess, err := session.NewSessionWithOptions(session.Options{
 		Config: aws.Config{
 			Region:   aws.String(n.conf.Sigv4.Region),
@@ -84,11 +109,7 @@ func (n *Notifier) Notify(ctx context.Context, alert ...*types.Alert) (bool, err
 		Profile: n.conf.Sigv4.Profile,
 	})
 	if err != nil {
-		if e, ok := err.(awserr.RequestFailure); ok {
-			return n.retrier.Check(e.StatusCode(), strings.NewReader(e.Message()))
-		} else {
-			return true, err
-		}
+		return nil, err
 	}
 
 	if n.conf.Sigv4.RoleARN != "" {
@@ -105,32 +126,37 @@ func (n *Notifier) Notify(ctx context.Context, alert ...*types.Alert) (bool, err
 				Profile: n.conf.Sigv4.Profile,
 			})
 			if err != nil {
-				if e, ok := err.(awserr.RequestFailure); ok {
-					return n.retrier.Check(e.StatusCode(), strings.NewReader(e.Message()))
-				} else {
-					return true, err
-				}
+				return nil, err
 			}
 		}
 		creds = stscreds.NewCredentials(stsSess, n.conf.Sigv4.RoleARN)
 	}
-	// Max message size for a message in a SNS publish request is 256KB, except for SMS messages where the limit is 1600 characters/runes.
-	messageSizeLimit := 256 * 1024
+	// Use our generated session with credentials to create the SNS Client.
 	client := sns.New(sess, &aws.Config{Credentials: creds})
-	publishInput := &sns.PublishInput{}
+	// We will always need a region to be set by either the local config or the environment.
+	if aws.StringValue(sess.Config.Region) == "" {
+		return nil, fmt.Errorf("region not configured in sns.sigv4.region or in default credentials chain")
+	}
+	return client, nil
+}
 
+func createPublishInput(ctx context.Context, n *Notifier, tmpl func(string) string) (*sns.PublishInput, error) {
+	publishInput := &sns.PublishInput{}
+	messageAttributes := createMessageAttributes(n, tmpl)
+	// Max message size for a message in a SNS publish request is 256KB, except for SMS messages where the limit is 1600 characters/runes.
+	messageSizeLimit := 256 * 1024
 	if n.conf.TopicARN != "" {
 		topicTmpl := tmpl(n.conf.TopicARN)
 		publishInput.SetTopicArn(topicTmpl)
-
 		if n.isFifo == nil {
+			// If we are using a topic ARN it could be a FIFO topic specified by the topic postfix .fifo.
 			n.isFifo = aws.Bool(n.conf.TopicARN[len(n.conf.TopicARN)-5:] == ".fifo")
 		}
 		if *n.isFifo {
 			// Deduplication key and Message Group ID are only added if it's a FIFO SNS Topic.
 			key, err := notify.ExtractGroupKey(ctx)
 			if err != nil {
-				return false, err
+				return nil, err
 			}
 			publishInput.SetMessageDeduplicationId(key.Hash())
 			publishInput.SetMessageGroupId(key.Hash())
@@ -143,36 +169,25 @@ func (n *Notifier) Notify(ctx context.Context, alert ...*types.Alert) (bool, err
 	}
 	if n.conf.TargetARN != "" {
 		publishInput.SetTargetArn(tmpl(n.conf.TargetARN))
-
 	}
 
 	messageToSend, isTrunc, err := validateAndTruncateMessage(tmpl(n.conf.Message), messageSizeLimit)
 	if err != nil {
-		return false, err
+		return nil, err
 	}
 	if isTrunc {
-		attributes["truncated"] = &sns.MessageAttributeValue{DataType: aws.String("String"), StringValue: aws.String("true")}
+		// If we truncated the message we need to add a message attribute showing that it was truncated.
+		messageAttributes["truncated"] = &sns.MessageAttributeValue{DataType: aws.String("String"), StringValue: aws.String("true")}
 	}
+
 	publishInput.SetMessage(messageToSend)
+	publishInput.SetMessageAttributes(messageAttributes)
 
 	if n.conf.Subject != "" {
 		publishInput.SetSubject(tmpl(n.conf.Subject))
 	}
 
-	publishInput.SetMessageAttributes(attributes)
-
-	publishOutput, err := client.Publish(publishInput)
-	if err != nil {
-		if e, ok := err.(awserr.RequestFailure); ok {
-			return n.retrier.Check(e.StatusCode(), strings.NewReader(e.Message()))
-		} else {
-			return true, err
-		}
-	}
-
-	level.Debug(n.logger).Log("msg", "SNS message successfully published", "message_id", publishOutput.MessageId, "sequence number", publishOutput.SequenceNumber)
-
-	return false, nil
+	return publishInput, nil
 }
 
 func validateAndTruncateMessage(message string, maxMessageSizeInBytes int) (string, bool, error) {
@@ -187,3 +202,12 @@ func validateAndTruncateMessage(message string, maxMessageSizeInBytes int) (stri
 	copy(truncated, message)
 	return string(truncated), true, nil
 }
+
+func createMessageAttributes(n *Notifier, tmpl func(string) string) map[string]*sns.MessageAttributeValue {
+	// Convert the given attributes map into the AWS Message Attributes Format
+	attributes := make(map[string]*sns.MessageAttributeValue, len(n.conf.Attributes))
+	for k, v := range n.conf.Attributes {
+		attributes[tmpl(k)] = &sns.MessageAttributeValue{DataType: aws.String("String"), StringValue: aws.String(tmpl(v))}
+	}
+	return attributes
+}