Serverless wsgi unable to import werkzeug - aws-lambda

Question

I'm having issues deploying my serverless application to AWS. In AWS the logs show:
Unable to import module 'wsgi_handler': No module named 'werkzeug'
I have explicitly specified werkzeug in my requirements.txt but it seems that when I run sls deploy the packages specified are not being put inside the zip file that is uploaded to my S3 bucket.
Below is a copy of my serverless.yml file:
service: serverless-flask
plugins:
- serverless-python-requirements
- serverless-wsgi
- serverless-dynamodb-local
custom:
tableName: 'transactions-table-${self:provider.stage}'
wsgi:
app: app.app # entrypoint is app.app, which means the app object in the app.py module.
packRequirements: false
pythonRequirements:
dockerizePip: true
dynamodb:
stages:
- test
- dev
start:
migrate: true
provider:
name: aws
runtime: python3.6
stage: dev
region: us-east-1
iamRoleStatements:
- Effect: Allow
Action:
- dynamodb:Query
- dynamodb:Scan
- dynamodb:GetItem
- dynamodb:PutItem
Resource:
- { "Fn::GetAtt": ["TransactionsDynamoDBTable", "Arn" ] }
environment:
TRANSACTIONS_TABLE: ${self:custom.tableName}
functions:
app:
handler: wsgi_handler.handler
events:
- http: ANY /
- http: 'ANY {proxy+}'
resources:
Resources:
TransactionsDynamoDBTable:
Type: 'AWS::DynamoDB::Table'
Properties:
AttributeDefinitions:
-
AttributeName: transactionId
AttributeType: S
-
AttributeName: timestamp
AttributeType: S
KeySchema:
-
AttributeName: transactionId
KeyType: HASH
-
AttributeName: timestamp
KeyType: RANGE
ProvisionedThroughput:
ReadCapacityUnits: 1
WriteCapacityUnits: 1
TableName: ${self:custom.tableName}
Here is my requirements.tx:
boto3==1.11.17
botocore==1.14.17
Click==7.0
docutils==0.15.2
Flask==1.1.1
itsdangerous==1.1.0
Jinja2==2.11.1
jmespath==0.9.4
MarkupSafe==1.1.1
python-dateutil==2.8.1
s3transfer==0.3.3
six==1.14.0
urllib3==1.25.8
Werkzeug==1.0.0
As far as I know, using the serverless-wsgi plugin should handle the installation of this package automatically but I'm seeing no .requirements folder being created in the .serverless folder or in the zipfile that serveless creates.
The requirements.txt file contained inside the zip faile only contains the following:
-i https://pypi.org/simple
I'm not sure what I'm doing wrong but the only solution so far has been to tear down the infrastructure and redeploy with a new url which isn't ideal.

Answer 1

Adding a reference to the lambda layer did the trick for me (see the layers section):
api:
timeout: 30
handler: wsgi_handler.handler
layers:
- {Ref: PythonRequirementsLambdaLayer}
events:
- http: ANY /

Answer 2

You need add your files manually to the package.
In your serverless.yml, add this
package:
individually: true
exclude:
- ./**
include:
- requirements.txt
- <other files>
Once you deploy, you can download the packaged zip from AWS and verify if your files are there.