A load balancer is a resource that can enable Internet and Yale-network-only web traffic to one or more EC2 VMs or ECS container replica(s). The load balancer holds the HTTPS certificate and serves as an encryption endpoint.
General Considerations
Selecting a load balancer depends on your Data Classification.
For web apps with Low Risk Data, you may use an AWS Application Load Balancer (“ALB”) in your AWS account
For web apps with High Risk and Moderate Risk Data you must use an ITS-managed F5 LTM load balancer in Yale’s on-prem data center.
Web Application Firewall (“WAF”)
Using a WAF is recommended for Low Risk Data and required for Moderate and High Risk Data. An AWS WAF may be used with your AWS ALB for low risk data. The implementation of a WAF for Moderate or High Risk data is up to you to research and configure.
Access Logging
It is important and required to log HTTP access logs - AWS ALB supports this via S3. Working examples are detailed in terraform below.
AWS Network Load Balancers (“NLB”)
NLB is an advanced load balancer - useful for complex configurations. It follows the same rules mentioned for Low Risk and High and Moderate Risk Data, plus WAF, and Access Logging. Configuration is left to the AWS account Sysadmin.
Low Risk - AWS ALBs
You can create public (and private) load balancers inside your AWS account for your low-risk web apps, with little help from ITS. You still need to request:
Approval for your domain name and website content from either ITS YaleSites or Yale School of Medicine (“YSM”) (ysm.editor@yale.edu).
A TLS certificate created via AWS for your approved domain name. How to create an AWS ACM Certificate
DNS configuration from ITS for the website friendly name, e.g., example.yale.edu. After you create an ALB, you will need to create a DNS CNAME in Yale DNS to point to the ALB DNS record.
Moderate and High Risk - ITS F5 LTM Load Balancer
ITS F5 LTM/BigIP Load Balancers will be requested through ServiceNow of the Load Balancing Team. You have to do the following work before you request a Load Balancer. Be prepared with ticket numbers, and/or, email threads supporting these actions:
Domain name validation and website content verification of ITS YaleSites or Yale School of Medicine (“YSM”).
Security Design Review (“SDR”) with ITS Security/ISO
Required Supporting Information for an ITS F5 LTM Load Balancer:
Name of the website or application
Desired Fully Qualified Domain Name (“FQDN”)
Brief description of the site or application.
NetId information for the site, application owner, COA for billing
IP address/AWS DNS Alias record of resource to be Load Balanced
High Level Steps to Create an AWS ALB
This is a technical multi-step process which is to be performed by a technical resource whom administers the AWS account, not ITS. A high level overview:
AWS ALB is applicable to low-risk data classification, web-apps
Review of domain name selection and website content by YaleSites, or Yale School of Medicine (“YSM”)
Backend load balancing target must use HTTPS, e.g., IIS, nginx, apache with self-signed certificate
yale.edu HTTPS SSL Certificates can use AWS Certificate Manager (“ACM”) - for the public facing load balancer
ALB can be setup manually, using command line, or with terraform as illustrated below
DNS requests for yale.edu domain name requested of “DNS” group in ServiceNow
Pre-requisite Information Gathering
Only create AWS ALBs for low-risk data web applications
How to verify that data is a low risk and perform data classification - Data Classification Policy
Moderate risk and high risk data classification services cannot use AWS ALB, and must load balance through ITS F5 LTM load balancing. Please open a support Incident in ServiceNow for Load Balancing for non-low-risk data-driven web apps.
Verify approval from YaleSites, and/or Yale School of Medicine ("YSM") med.yale.edu domain names, for the domain name and website content
For Yalesites approval - *.yale.edu - email webmaster@yale.edu
For med.yale.edu domain names, email the YSM, ysm.editor@yale.edu
Enter useful tag information for accounting purposes
Technical Documentation
Creating AWS ALBs with terraform
https://github.com/YaleUniversity/yalecloud-terraform-examples
Backend targets
Create an HTTPS listener on the backend web app
E.g., nginx self-signed certificate listening on port 443/HTTPS
Configure the access logging to an S3 bucket in your account.
Optionally, configure WAF
AWS Certificate Manager (“ACM”)
You will need valid HTTPS/TLS certificates for AWS ALBs.
You can request valid yale.edu certificates via the AWS console inside ACM. Choose email validation, and automatically YaleSites (Yale Webmaster - webmaster@yale.edu) will be emailed. Requests should be appropriate for department and initiative, not too generic, and not wildcard for *.yale.edu.
Follow-up with an email to the YaleSites team
To: Lutinski, Robert robert.lutinski@yale.edu; Johnson, J'Vaughn jvaughn.johnson@yale.edu
Cc: Cloud Engineering cloudeng@yale.edu; webmaster@yale.edu webmaster@yale.edu
Subject: AWSCertificate Validation for - example.yale.edu
Hello,
FYI, a request for domain name owner validation is incoming: example.yale.edu. This is for the ${my-webapp-namedservice}, for use in the AWS Certificate Manager ("ACM").
Thank you,
Best,
<your name>
DNS Requests
Request Public/Private DNS CNAME requests through the "DNS" group via ServiceNow Incident
Use the following template to create a DNS record and assign a ticket to the DNS group in ServiceNow (“SNOW”).
Create an Incident in Service Now assigned to the “Business service:” Infrastructure & Internet > Network Services > IP & DNS Support
Get tagging/metadata for the DNS team as show below
Short description:Create Private/Public DNS record for an AWS ALB: example.yale.edu
Hi,
Please create the following private/public DNS record(s):
CNAME:
example.yale.edu: example-yale-edu.${AWSaccountID}.us-east-1.elb.amazonaws.com.
metadata:
Description: A concise description of your web app
Device Type: AWS ALB
Location: us-east-1
Phone number: changeme
Primary User NetID: changeme
Thanks,
Your name