This post will describe how I choose to implement an AWS Lambda function to build a static website. As I alluded to in the previous post, here are the details.

I just open sourced my first AWS #Lambda function! GitHub Push webhook > SNS > Lambda https://t.co/Lh1PzTyE2H More details and docs to come.

— Jeremy Olexa (@jolexa) December 29, 2015

For those not familar with Lambda, please see https://aws.amazon.com/lambda/ - the slogan fits, “Run code, not servers” and it is really neat if you can find a practical application.

My experience writing this function was mixed. Yes, it is awesome that I only need to do a git push and the function pushes code to website. No, it was not fun writing the function since debugging this service is not realtime and pretty painful. Since Hugo is written in Go, I could easily build the site anywhere without a complicated localhost setup or build environment. However, since the website is now serverless, I wanted a serverless method to push code as well. It works, it isn’t super pretty but now I don’t have to touch it again.

My implementation is different than other’s work that I have found. When I searched for some ideas on how to do this, I found that most people were operating on S3 events. This is fine, but it still needed some human/thing to push the raw content into S3 first. Then I see that there are many people using Wercker to automate the deployment, but that seems non- ideal to me when we have the option to use Lambda for free as well. I, personally, want to minimize the amount of services in play.

Step - by - Step (Simple)

1. Configure your repo to push to AWS SNS Topic - you will have to configure this topic
   • Github Repo Settings -> Webhooks and Services
2. Configure an IAM role in AWS account that allows Cloudwatch Logging and S3 list/put/get/delete on the bucket where your content is going
   • The function assumes the bucket name is named the exact same as the repo name
3. Build a Lambda function that receives events from the SNS Topic.
   • Deploy the built zip from hugo-lambda-function
4. Done. Enjoy adding a serverless build system to the pipeline for your static site.

Cost

I mentioned that this is free. It is technically true. My implementation takes about a minute to run in the worst case (syncing to S3 takes the longest), so it can run about 53,300 times in a month before I will get charged. That seems like many, many posts more than I will ever do, I’ll optimistically say that this will get ran 1-4 times per month.

Leave a comment if something should be explained better or use GitHub issues, otherwise enjoy.