K
Q

Introspecting Docker/Kubernetes Runtime to check whether it is a Docker Container or a Container within a POD in Kubernetes Cluster

1/26/2020

How can I check whether it is plain vanilla docker container or a container wrapped in a pod by way of a very simple introspection during runtime?

-- Naga Vijayapuram
aws-eks
aws-fargate
azure-aks
google-kubernetes-engine
kubernetes

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1 Answer

1/26/2020

Kubernetes sets many environment variables inside the container by default. You can check if any of them are set. eg: KUBERNETES_SERVICE_HOST

# kubectl exec -it api-server-594f9684b-jg2d4 env | grep KUBERNETES
KUBERNETES_SERVICE_PORT_HTTPS=443
KUBERNETES_SERVICE_PORT=443
KUBERNETES_SERVICE_HOST=10.96.0.1
KUBERNETES_PORT_443_TCP_PORT=443
KUBERNETES_PORT_443_TCP_PROTO=tcp
KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
KUBERNETES_PORT=tcp://10.96.0.1:443

https://kubernetes.io/docs/concepts/containers/container-environment-variables/

-- Shashank V
Source: StackOverflow