[Python] Python Lambda to send files uploaded to s3 as email attachments

We have an online form that gives people the option to upload multiple files. The form is built by a third party, so I don't have any involvement with them. When someone uploads files using the form it dumps the files into a new folder within an s3 bucket. I want to be able to do the following:

Get the files triggered by form filler's upload Attach the files to an email Send the email to specific people.

I have done quite a lot of research, but I'm still new to coding and am trying to use Python, which I have decided to focus on as my first proper language.

The code I have got so far is borrowed from other examples I have seen and adjusted. But so far it has only sent me emails with the files when I have uploaded single files into the root of the bucket. Not multiple files into a folder in the bucket. This appears to be because the / in the path of the files in folders breaks the sendrawemail functionality.

This lambda is set up to be triggered by a PUT notification on the creation of new files on the s3 bucket. UPDATE: I have now used different code and have got a solution. Please see the bottom for this.

from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.mime.application import MIMEApplication
import boto3

def lambda_handler(event, context):
file_obj = event["Records"][0]
bucket_name = str(file_obj['s3']['bucket']['name'])
key = str(file_obj['s3']['object']['key'])
msg = MIMEMultipart()
new_body = "test body"
text_part = MIMEText(new_body, _subtype="html")
msg.attach(text_part)

filename = str(event["Records"][0]['s3']['object']['key'])
msg["To"] = "test@test.com"
msg["From"] = "test@test.com"
s3_object = boto3.client('s3')
s3_object = s3_object.get_object(Bucket=str(bucket_name), Key=str(key))
body = s3_object['Body'].read()

part = MIMEApplication(body, filename)
part.add_header("Content-Disposition", 'attachment', filename=filename)
msg.attach(part)
ses_aws_client = boto3.client('ses', 'eu-west-1')
ses_aws_client.send_raw_email(RawMessage={"Data" : msg.as_bytes()})


What I hoped was that when a folder, or multiple files were uploaded, I would be sent an email containing all of the files as attachments (I realise there's a 10mb limit to messages). However, when there are multiple files it appears to be sending multiple emails with one file per email. And if the file is in a folder, so has a key value with a slash in it, the send_raw_email shows the following error:

[ERROR] ClientError: An error occurred (InvalidParameterValue) when calling the SendRawEmail operation: Expected ';', got "/"


I presume I need to encode the path in some way? Is there any way of collating all the files newly uploaded into one email?

Any help would be massively welcome.

Edit 1: As per Jeril's response, I'm sharing the full log entry from the failure. Also I missed a line in my original code block so I will update that, too.

12:14:59
[ERROR] ClientError: An error occurred (InvalidParameterValue) when calling the SendRawEmail operation: Expected ';', got "/" Traceback (most recent call last): File "/var/task/lambda_function.py", line 26, in lambda_handler ses_aws_client.send_raw_email(RawMessage={"Data" : msg.as_bytes()}) File "/var/runtime/botocore/client.py", line 320, in _api_call return self._make_api_call(opera
[ERROR] ClientError: An error occurred (InvalidParameterValue) when calling the SendRawEmail operation: Expected ';', got "/"
Traceback (most recent call last):
File "/var/task/lambda_function.py", line 26, in lambda_handler
ses_aws_client.send_raw_email(RawMessage={"Data" : msg.as_bytes()})
File "/var/runtime/botocore/client.py", line 320, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/var/runtime/botocore/client.py", line 623, in _make_api_call
raise error_class(parsed_response, operation_name)


Update: I have now managed to get the essential functionality of this working:

import os.path
import boto3
import email
from botocore.exceptions import ClientError
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication


s3 = boto3.client("s3")

def lambda_handler(event, context):
# Replace sender@example.com with your "From" address.
# This address must be verified with Amazon SES.
SENDER = "Test Test <test@test.com>"

# Replace recipient@example.com with a "To" address. If your account
# is still in the sandbox, this address must be verified.
RECIPIENT = "Test Test <test@test.com>"

# Specify a configuration set. If you do not want to use a configuration
# set, comment the following variable, and the
# ConfigurationSetName=CONFIGURATION_SET argument below.
# CONFIGURATION_SET = "ConfigSet"

AWS_REGION = "eu-west-1"
SUBJECT = "Test Send Mesage with Attachment"

# This is the start of the process to pull the files we need from the S3 bucket into the email.
# Get the records for the triggered event
FILEOBJ = event["Records"][0]
# Extract the bucket name from the records for the triggered event
BUCKET_NAME = str(FILEOBJ['s3']['bucket']['name'])
# Extract the object key (basicaly the file name/path - note that in S3 there are
# no folders, the path is part of the name) from the records for the triggered event
KEY = str(FILEOBJ['s3']['object']['key'])

# extract just the last portion of the file name from the file. This is what the file
# would have been called prior to being uploaded to the S3 bucket
FILE_NAME = os.path.basename(KEY)

# Using the file name, create a new file location for the lambda. This has to
# be in the tmp dir because that's the only place lambdas let you store up to
# 500mb of stuff, hence the '/tmp/'+ prefix
TMP_FILE_NAME = '/tmp/' +FILE_NAME

# Download the file/s from the event (extracted above) to the tmp location
s3.download_file(BUCKET_NAME, KEY, TMP_FILE_NAME)

# Make explicit that the attachment will have the tmp file path/name. You could just
# use the TMP_FILE_NAME in the statments below if you'd like.
ATTACHMENT = TMP_FILE_NAME

# The email body for recipients with non-HTML email clients.
BODY_TEXT = "Hello,\r\nPlease see the attached file related to recent submission."

# The HTML body of the email.
BODY_HTML = """\
<html>
<head></head>
<body>
<h1>Hello!</h1>
<p>Please see the attached file related to recent submission.</p>
</body>
</html>
"""

# The character encoding for the email.
CHARSET = "utf-8"

# Create a new SES resource and specify a region.
client = boto3.client('ses',region_name=AWS_REGION)

# Create a multipart/mixed parent container.
msg = MIMEMultipart('mixed')
# Add subject, from and to lines.
msg['Subject'] = SUBJECT
msg['From'] = SENDER
msg['To'] = RECIPIENT

# Create a multipart/alternative child container.
msg_body = MIMEMultipart('alternative')

# Encode the text and HTML content and set the character encoding. This step is
# necessary if you're sending a message with characters outside the ASCII range.
textpart = MIMEText(BODY_TEXT.encode(CHARSET), 'plain', CHARSET)
htmlpart = MIMEText(BODY_HTML.encode(CHARSET), 'html', CHARSET)

# Add the text and HTML parts to the child container.
msg_body.attach(textpart)
msg_body.attach(htmlpart)

# Define the attachment part and encode it using MIMEApplication.
att = MIMEApplication(open(ATTACHMENT, 'rb').read())

# Add a header to tell the email client to treat this part as an attachment,
# and to give the attachment a name.
att.add_header('Content-Disposition','attachment',filename=os.path.basename(ATTACHMENT))

# Attach the multipart/alternative child container to the multipart/mixed
# parent container.
msg.attach(msg_body)

# Add the attachment to the parent container.
msg.attach(att)
print(msg)
try:
#Provide the contents of the email.
response = client.send_raw_email(
Source=SENDER,
Destinations=[
RECIPIENT
],
RawMessage={
'Data':msg.as_string(),
},
# ConfigurationSetName=CONFIGURATION_SET
)
# 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'])


The only issue now is that if I upload multiple files, I get sent an email per file. Is there any way of collating them all into one email?

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