AWS SNS 自定義郵件格式
AWS 的 SES (Simple Email Service) 可以提供郵件收發服務。對於郵件收發的反饋，如 Bounce message, 可以傳送到 SNS (Simple Notification Service) 作進一步處理。SNS 可以指定某個郵件地址作為訂閱者，將訊息傳送到該郵箱中。然而，SNS發出來的郵件是 JSON，可讀性不好，例如：
{"notificationType":"Delivery","mail":{"timestamp":"2019-02-18T06:03:02.669Z","source":"[email protected]","sourceArn":"arn:aws:ses:us-west-2:xxxxxx:identity/feichashao.com","sourceIp":"205.251.234.36","sendingAccountId":"xxxxxx","messageId":"01010168ff335c8d-f00ce1c1-e103-49cd-912f-9f397c7a463c-000000","destination":["[email protected]"],"headersTruncated":false,"headers":[{"name":"From","value":"[email protected]"},{"name":"To","value":"[email protected]"},{"name":"Subject","value":"free kfc"},{"name":"MIME-Version","value":"1.0"},{"name":"Content-Type","value":"text/plain; charset=UTF-8"},{"name":"Content-Transfer-Encoding","value":"7bit"}],"commonHeaders":{"from":["[email protected]"],"to":["[email protected]"],"subject":"free kfc"}},"delivery":{"timestamp":"2019-02-18T06:03:03.917Z","processingTimeMillis":1248,"recipients":["[email protected]"],"smtpResponse":"250 2.0.0 OK 1550469783 q2si13329671plh.79 - gsmtp","remoteMtaIp":"74.125.20.27","reportingMTA":"a27-30.smtp-out.us-west-2.amazonses.com"}}
怎麼能讓這個提醒郵件變得更加友好呢？ SNS目前不支援自定義郵件格式。一個思路是，將 SNS 的訊息傳送到 Lambda 上，讓 Lambda 處理好格式後，再發送到指定郵箱。即 SES -> SNS -> Lambda -> SES.
建立 SNS Topic
建立一個SNS Topic, 比如名字叫"email-notify".
建立 Lambda Function
使用 Lambda 的 Blueprints ses-notification-python 作為模板，建立以下 Lambda Function.
這裡主要修改了 handle_delivery 這個 Handler, 期望每次 SES 傳送郵件後，都會觸發這個 Handler, 將相關資訊傳送到管理員郵箱。
from __future__ import print_function
import json
import boto3
from botocore.exceptions import ClientError
def lambda_handler(event, context):
message = json.loads(event['Records'][0]['Sns']['Message'])
notification_type = message['notificationType']
handlers.get(notification_type, handle_unknown_type)(message)
def handle_bounce(message):
message_id = message['mail']['messageId']
bounced_recipients = message['bounce']['bouncedRecipients']
addresses = list(
recipient['emailAddress'] for recipient in bounced_recipients
)
bounce_type = message['bounce']['bounceType']
print("Message %s bounced when sending to %s. Bounce type: %s" %
(message_id, ", ".join(addresses), bounce_type))
def handle_complaint(message):
message_id = message['mail']['messageId']
complained_recipients = message['complaint']['complainedRecipients']
addresses = list(
recipient['emailAddress'] for recipient in complained_recipients
)
print("A complaint was reported by %s for message %s." %
(", ".join(addresses), message_id))
def handle_delivery(message):
message_id = message['mail']['messageId']
delivery_timestamp = message['delivery']['timestamp']
header_from = message['mail']['commonHeaders']['from'][0]
header_to = message['mail']['commonHeaders']['to'][0]
print("Message %s was delivered successfully at %s" %
(message_id, delivery_timestamp))
SENDER = "feichashao-ses <[email protected]>"
RECIPIENT = "[email protected]"
AWS_REGION = "us-west-2"
SUBJECT = "Amazon SES Test (SDK for Python)"
BODY_TEXT = ("Amazon SES Test (Python)\r\n"
"This email was sent with Amazon SES using the "
"AWS SDK for Python (Boto)."
)
BODY_HTML = """<html>
<head></head>
<body>
<h1>Email Delivery</h1>
<p>From: {}</p>
<p>To: {}</p>
</body>
</html>
""".format(header_from, header_to)
CHARSET = "UTF-8"
client = boto3.client('ses',region_name=AWS_REGION)
try:
#Provide the contents of the email.
response = client.send_email(
Destination={
'ToAddresses': [
RECIPIENT,
],
},
Message={
'Body': {
'Html': {
'Charset': CHARSET,
'Data': BODY_HTML,
},
'Text': {
'Charset': CHARSET,
'Data': BODY_TEXT,
},
},
'Subject': {
'Charset': CHARSET,
'Data': SUBJECT,
},
},
Source=SENDER,
)
# Display an error if something goes wrong.
except ClientError as e:
print(e.response['Error']['Message'])
else:
print("Email sent! Message ID:"),
print(response['MessageId'])
def handle_unknown_type(message):
print("Unknown message type:\n%s" % json.dumps(message))
raise Exception("Invalid message type received: %s" %
message['notificationType'])
handlers = {"Bounce": handle_bounce,
"Complaint": handle_complaint,
"Delivery": handle_delivery}
在 Designer 中，將剛剛建立的 SNS 作為 Trigger。
建立 SES 服務
上面兩個都是為 SES 服務的。現在，建立一個 SES 服務。認證一個 Domain 作為郵件傳送方，認證一個 Email 作為郵件接收方。
點進 SES 的 Domain（以 feichashao.com 為例），點開 Notification 一欄，點選 Edit Configuration, 將 Deliveries 選擇為上面的 SNS topic，如 "email-notify".
回到 Domain 的介面，點選 Send a Test Email 進行測試。傳送者是 [email protected]，收件人是 [email protected]。在郵件傳送成功後，Lambda 應該會收到 SNS 的資訊，然後 Lambada 會把 JSON 整理後，傳送到管理員郵箱 [email protected].
Email Delivery From: [email protected] To: [email protected]