What is letslambda?

colesbury/letslambda — explained in plain English

Analysis updated 2026-07-03 · repo last pushed 2017-06-04

Audience · ops devopsComplexity · 4/5DormantSetup · moderate

Mindmap

mindmap
  root((repo))
    What it does
      Gets free SSL certs
      Renews automatically
      Installs to load balancer
    Tech stack
      AWS Lambda
      Route 53
      S3 Storage
      Elastic Load Balancer
    Use cases
      Startup HTTPS
      Side project security
      Mobile app pinning
    Audience
      AWS users
      Ops teams
      Startup founders

mindmap root((repo)) What it does Gets free SSL certs Renews automatically Installs to load balancer Tech stack AWS Lambda Route 53 S3 Storage Elastic Load Balancer Use cases Startup HTTPS Side project security Mobile app pinning Audience AWS users Ops teams Startup founders

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What do people build with it?

USE CASE 1

Automate SSL certificate renewal for AWS-hosted websites to avoid manual work every few months.

USE CASE 2

Secure a startup or side project with free HTTPS using Let's Encrypt instead of paid certificate services.

USE CASE 3

Maintain the same private key across certificate renewals for mobile apps that use public key pinning.

What is it built with?

AWS LambdaPythonLet's EncryptAmazon Route53Amazon S3Elastic Load BalancerAWS KMS

How does it compare?

	colesbury/letslambda	0xhassaan/nn-from-scratch	0xzgbot/hermes-comfyui-skills
Stars	—	0	0
Language	—	Python	—
Last pushed	2017-06-04	—	—
Maintenance	Dormant	—	—
Setup difficulty	moderate	moderate	easy
Complexity	4/5	4/5	1/5
Audience	ops devops	developer	designer

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · moderate Time to first run · 1h+

Requires packaging and uploading to AWS Lambda plus configuring IAM permissions for Route53, S3, and your Elastic Load Balancer.

The license is not mentioned in the repository explanation, so the usage terms are unknown.

So what is it?

LetsLambda automates the process of getting and renewing SSL certificates for websites hosted on Amazon Web Services (AWS). SSL certificates are what make your website load over HTTPS instead of HTTP, giving visitors that secure padlock icon in their browser. Normally, you have to manually request these certificates, prove you own the domain, install them on your load balancer, and remember to repeat the whole process every few months before they expire. This tool handles all of that automatically. The tool runs as a small piece of code on AWS Lambda, which is essentially Amazon's platform for running code on a schedule without managing a server. When it runs, it talks to Let's Encrypt (a free certificate authority) to request or renew a certificate. To prove you own the domain, it automatically creates a temporary DNS record through Amazon Route53. Once the certificate is issued, the tool saves it in an Amazon S3 storage bucket and installs it directly onto your Elastic Load Balancer, which is the AWS service that distributes incoming web traffic to your servers. This is built for teams already hosting their websites on AWS who want to use free Let's Encrypt certificates without the ongoing manual hassle. For example, if you run a startup or a side project on AWS and want proper HTTPS without paying for premium certificate services, this handles it for you. It's especially useful if you develop mobile apps, since it can reuse the same private key across renewals, which matters for a security technique called public key pinning. The setup is somewhat involved because it needs to be packaged and uploaded to AWS, and it requires configuring specific permissions so the tool can securely access your load balancer, DNS, and storage. The README provides step-by-step instructions for this process, including a template that automates much of the deployment. It also takes security seriously: private keys can be encrypted using AWS's key management service, and access is tightly controlled through dedicated permission policies.

Copy-paste prompts

Prompt 1

I want to use LetsLambda to automate SSL certificate renewal on my AWS load balancer. Walk me through the step-by-step setup process including the IAM permissions I need to configure.

Prompt 2

I already have a LetsLambda deployment running on AWS Lambda. How do I enable private key encryption using AWS KMS, and what permission policies do I need to update?

Prompt 3

I'm setting up LetsLambda for the first time. Help me configure the Route53 DNS challenge and S3 bucket storage so that Let's Encrypt can verify my domain ownership automatically.

Frequently asked questions