STEPS
TO CREATE LAMBDA LAYER:
Below are the steps to create a lambda layer in AWS.
1) Navigate to Lamdba and choose Layers from Dashboard.
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| Lambda Layer |
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| Options to upload Zip file |
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| Lambda Layer |
HOW TO USE LAMBDA LAYER IN LAMBDA FUNCTION:
Below are the steps to add the lambda layer in the desired lambda function.
· 1) Go to the desired lambda function. Click on the Layers and choose the “Add a layer” option.
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| Add a layer - AWS Lambda |
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| Choose a layer - AWS Lambda |
If Below might the error that you may face while using the lambda layer in a function.
ERROR MESSAGE: No module found
SOLUTION: Probably because your deployment package doesn't have a proper structure.
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| Lambda Layer Structure |
ERROR MESSAGE: Task timed out after 3.00 seconds
SOLUTION: Increase the timeout period, you can increase it up to 15 mins it is under the configuration tab.
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| Configuration - AWS Lambda |
Lambda Layers:
An archive containing additional code, such as libraries, dependencies, or even custom runtimes. When you include a layer in a function, the contents are extracted to the /opt directory in the execution environment.
Run the commands mentioned below to create the package
for lambda layers in the EC2 server.
The Lambda Layer you are creating should have the below structure or else will get the error message “No module found” while importing the module in lambda function.
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| Lambda Layer Structure |
mkdir -p build/python/lib/python3.6/site-packages
ls usr/bin/python* sudo update-alternatives --install /usr/bin/python3 python /usr/bin/python3.6 1 sudo update-alternatives --config python3 sudo apt install python3-pip
pip3 install pandas xlrd -t build/python/lib/python3.6/site-packages/ --system
cd build/ zip -r9 Python3.6_Pandas_Lib.zip *
Before moving on to the code, let's go through about the /tmp directory provided by the Lambda function.
Here I have taken a scenario to copy an S3 object from PROD to DEV using boto3 in a lambda function.
import boto3 # AWS credentials of PROD environemnt s3 = boto3.client('s3',aws_access_key_id='awsAccessKey', aws_secret_access_key='awsSecretAccessKey') # AWS credentials of DEV environemnt s3Dev = boto3.client('s3',aws_access_key_id='awsAccessKeyDev', aws_secret_access_key=awsSecretAccessKeyDev) def lambda_handler(event, context): #Downloads the file from PROD S3 bucket and saves in temporary storage s3.download_file('source_bucket', 'folder/source.csv', '/tmp/source.csv') print('File Downloaded') file = '/tmp//source.csv' #Uploads the file in temporary space to DEV S3 bucket s3Dev.upload_file(file , 'target_bucket','folder/target.csv') print('File Uploaded') return { 'statusCode': 200 }