By Scott Miller
I noticed that in the documentation https://www.digitalocean.com/docs/kubernetes/how-to/configure-load-balancers/ the following statement is made
By default, the load balancer performs health checks on the worker nodes over HTTP on port 80 at the webserver root.
However, when I look at the LB configuration UI for a K8s cluster, it is set to tcp://0.0.0.0:30666
Which should it be? What if the scheduler puts all of the pods that respond to http on only one node? It seems like this default rule would direct traffic to a node that couldn’t serve it?
This textbox defaults to using Markdown to format your answer.
You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!
Accepted Answer
Hi there,
What youre seeing there is a nodeport that is where the LB checks the health on the node. If you use kubectl to describe the pertinent service you will see that this 30666 nodeport translates to a different container port (probably 80).
kubectl describe svc <service_name> give output like this:
… Port: http 80/TCP TargetPort: http/TCP NodePort: http 30541/TCP …
In my example the LB reaches the node on port 30541 but that traffic actually hits the container on port 80. That is what is meant by that sentence.
Become a contributor for community
Get paid to write technical tutorials and select a tech-focused charity to receive a matching donation.
DigitalOcean Documentation
Full documentation for every DigitalOcean product.
Resources for startups and SMBs
The Wave has everything you need to know about building a business, from raising funding to marketing your product.
The developer cloud
Scale up as you grow — whether you're running one virtual machine or ten thousand.
Get started for free
Sign up and get $200 in credit for your first 60 days with DigitalOcean.*
*This promotional offer applies to new accounts only.