<p>Is it possible to provide environment variables which will be set in all pods instead of configuring in each pods spec?</p>
<p>If not natively possible in Kubernetes, what would be an efficient method to accomplish it? We have Helm, but that still requires a lot of duplication.</p>
<p>This old answer suggested &quot;PodPreset&quot; which is no longer part of Kubernetes: <a href="https://stackoverflow.com/q/54550933/591975">Kubernetes - Shared environment variables for all Pods</a></p>

sean
<p>You could do this using a <a href="https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#mutatingadmissionwebhook" rel="nofollow noreferrer">mutating admission webhook</a> to inject the environment variable into the pod manifest.</p>
<p>There are more details on implementing webhooks <a href="https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#request" rel="nofollow noreferrer">here</a>.</p>
