I've a requirement to update a value in all the running containers in GKE. We have designed the Restful web service which will update the some property values at run time but that values should be updated in all the running instance. I want to know how can in send the request to all the containers. We are currently using GKE(Google Kubernetes Engine) and Ingress Load balancer. I've been searching for a solution but couldn't figure out solution.
I am not sure about your use case but certainly, this isn't a good practice and never recommended. A container shouldn't be changed during their life span.
For similar kind of use case, Kubernetes (K8S) offers a config map which stores the values which can be modified and shared by containers.
But as you've written REST, I guess that you want to modify values through some kind of REST service call and want those values to be available to all containers. By the other hand, you can move those values to persistence storage like DB and with a single call change values at storage and let all container read from that storage so that feature container can also have access to those updated values.
Hope this helps!
You can use configmap or kubernetes secrets do the same