Maximum allowed size for functions

[jonasgroendahl]

Hi,

com.amazonaws.services.cloudfront.model.InvalidLambdaFunctionAssociationException: The function code size is larger than the maximum allowed size for functions that are triggered by a CloudFront event

I am getting this error following this guide (Step 2.ii): https://github.com/Widen/cloudfront-auth/wiki/Manual-Deployment. It seems the lambda zip it creates when I run ./build.shis too large.

I read up on the quotas, it seems like the 1MB is being exceeded for viewer requests: https://imgur.com/a/pSuzrFg

Did I do something wrong or is this normal? I'm trying to setup a lambda edge function with my cloudfront distribution to authenticate with Azure AD

[jonasgroendahl]

Changing the build script to
npm install --only=production && cd build && npm install --only=production && cd .. && node build/build.js

worked so far :) but I had to manually copy some files to the .zip file that is required.

[loadfix]

worked so far :) but I had to manually copy some files to the .zip file that is required.

What files did you need to manually copy?

[nickshine]

Hey @jonasgroendahl @loadfix , so the way I use this currently is via its counterpart terraform module, which pulls in the zip, and adds in the config necessary for the lambda@edge function to work.

[guizy67]

worked so far :) but I had to manually copy some files to the .zip file that is required.

What files did you need to manually copy?

In my case I only had to add the simpleurl.js file to the .zip file.
I changed the build/build.js file like this (line 105):

writeConfig(config, zip, ['config.json', 'index.js', 'auth.js', 'nonce.js', 'simpleurl.js']);

This seems to do the trick...

Remember to remove the node_modules and build/node_modules directories or you will still get the full sized zip file (28MB in my case)

[nickshine]

@guizy67 looks like I missed that as I use a different method to build the zip for release:

https://github.com/nickshine/lambda-edge-azure-auth/blob/master/package.sh#L9-L20

For the released zip, you only have to add in your config.json, everything else should be good.

I'll put in a fix for the build.js script though, thanks!

[bkozlik]

For anyone else running into a build issue on Windows 10, here are the steps that worked for me:

1. Install "zip" utility in Git bash (MinGW64). (See addendum to this comment for instructions)
2. Run the build.sh script from a Git bash shell and put in your Cloudfront info and AD tenant info.
3. Open the zip file generated in the distribution folder, and delete node_modules from it
4. Run command "npm prune --production"
5. Copy folder node_modules into the zip file.
6. Copy file "simpleurl.js" into the zip file.
7. Upload Zip file to AWS Lambda. Final zip file size came out to around 560kb... big difference from original 26mb size.

Addendum: Installing zip CLI on Windows
https://stackoverflow.com/questions/38782928/how-to-add-man-and-zip-to-git-bash-installation-on-windows
Navigate to this sourceforge page

Top answer copy/paste:
Download zip-3.0-bin.zip
In the zipped file, in the bin folder, find the file zip.exe.
Extract the file zip.exe to your mingw64 bin folder (for me: C:\Program Files\Git\mingw64\bin)
Navigate to to this sourceforge page
Download bzip2-1.0.5-bin.zip
In the zipped file, in the bin folder, find the file bzip2.dll
Extract bzip2.dll to your mingw64\bin folder (same folder as above: C:\Program Files\Git\mingw64\bin)

[bkozlik]

Update: I was able to get this Lambda function deployed but it never worked right for my setup; it gets stuck in a loop and eventually fails with a 403 or 500.

In case anyone else is ending up at this point and scratching their head about what to do next, here's the approach that finally worked for me:

1. Set up Cognito Pool with Azure AD selected as the SAML IDP. I followed this tutorial: https://aws.amazon.com/blogs/security/how-to-set-up-amazon-cognito-for-federated-authentication-using-azure-ad/
2. Set up the "cognito-at-edge" Lambda as your CloudWatch Lambda@Edge Request handler: https://github.com/awslabs/cognito-at-edge
3. Enjoy SSO