Are you experiencing an “Invalid ELF header” error when executing your AWS Lambda? If so, you have came to the right place for help. We will discuss the root cause of this error and how to solve this issue with the help of Docker.
Root cause for invalid elf header error
When executed, AWS Lambdas run on a Linux platform. If you are experiencing an invalid ELF header error, it is because the binaries included in your deployment package were built for a platform other than Linux. Typically you will see this issue when you develop your lambda in a non Linux environment.
How to resolve an invalid ELF header error
Now that we know why we are experiencing this issue, it is time to find a solution. This is where Docker comes into the picture. After you have developed your AWS Lambda, you should spin up a linux container with a bind mount, install all of your dependencies, and create your deployment package. This will ensure that all of your binaries are Linux compatible, resolving your invalid ELF header issue.
Creating a python AWS Lambda deployment using Docker
First we need to start an Ubuntu Docker container with a bind mount.
docker run -v directory_to_lambda_code:/lambda -it --rm ubuntu
Next, we install python3, pip, and zip.
apt-get update && apt-get install -y -qq python3-pip git \ && cd /usr/local/bin && ln -s /usr/bin/python3 python \ && python3 -m pip install --upgrade pip \ && python3 -m pip install ipython \ && rm -rf /var/lib/apt/lists/*
apt-get update && apt-get install zip
At this point, we can change to the directory that contains our code and begin installing all required python modules.
cd /lambda
pip install -t . pip_module_name
Finally, we can create our deployment package.
zip -r9 name_of_deployment_package .
Conclusion
With our newly created python AWS Lambda deployment package, we can now upload and execute our lambda without fear of encountering an invalid ELF header error.
If you have further questions regarding AWS Lambdas, please do not hesitate to contact us.
