Is it possible to disable service discovery with environment variables in kubernetes?

user_5565855 0
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As we know, kubernetes supports 2 primary modes of finding a Service - environment variables and DNS, could we disable the first way and only choose the DNS way?

kubernetes
2 Answers

As shown in this PR, this feature will land with Kubernetes v1.13. From the PR (as Docs are not available yet) I expect it to be the field enableServiceLinks in the pod spec with true as default.

Edit: It has been a while and the PR finally landed. The enableServiceLinks was added as an optional Boolean to the Kubernetes PodSpec.

For the record: using DNS to discover service endpoints is the recommended approach. The docker link behavior, from where the environment variables originate, has long been deprecated.

user_34376060

Per kubernetes v1.8 source, it's impossible to disable services discovery with environment variables.

Only service meet either condition is exposed by envVars.

  • service in the same namespace as the pod;
  • kubernetes service in the default namespace;

Even though, these environment variables can be overwritten by env and envFrom defined in pod template.

I'm wondering what's your scenario, maybe we can figure out some workaround.

user_6920760
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