Question

Load Balancer Sticky Cookie (Kubernetes)

Posted on November 2, 2024
DigitalOcean Managed Load Balancers Load Balancing DigitalOcean Kubernetes
Asked by Ben Buzbee

Hey so I have a load balancer setup with sticky cookies:

    service.beta.kubernetes.io/do-loadbalancer-sticky-sessions-type: "cookies"
    service.beta.kubernetes.io/do-loadbalancer-sticky-sessions-cookie-name: "storythreads-sticky-session"
    service.beta.kubernetes.io/do-loadbalancer-sticky-sessions-cookie-ttl: "3600" # 1 hr cookie duration; I assume its refreshed each time

A big problem I have though, is those cookies are set with SameSite=Lax - which means they cant be used in fetch requests cross origin.

I really need some way of changing that to None so that I can use fetches that have stickyness.

Any advice please?

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Bobby Iliev

Site Moderator

• December 5, 2024

Hi Ben,

As far as I can see from the DigitalOcean Managed Load Balancer documentation, sticky sessions are implemented at the load balancer layer. The cookies used for sticky sessions are set and stripped by the load balancer before the request reaches your backend application. This means that these cookies are not available to your backend applications, making them unsuitable for backend logic or cross-origin use cases.

As per the documentation:

Sticky session cookies are managed entirely by the load balancer.
They are stripped from the request before forwarding it to the backend, so they cannot be directly accessed or modified by your application.

Also on another note, Load Balancer sticky sessions only work with:

SSL termination (e.g., port 443 to port 80) or
HTTP requests (port 80 to port 80).

They do not work with SSL passthrough (port 443 to 443). Make sure your load balancer is terminating SSL and forwarding the request to your backend over HTTP or HTTPS for sticky sessions to function.

https://docs.digitalocean.com/glossary/sticky-session/#load-balancer

As you’re deploying on Kubernetes, using an ingress controller like NGINX Ingress gives you more control over cookies. For example, you can set cookie attributes directly in the ingress annotations: