Kubernetes version 1.13 and lower

They cannot be shared, because they cannot be accessed from a pods outside of its namespace. Names of resources need to be unique within a namespace, but not across namespaces.

Workaround it is to copy it over.

Copy secrets between namespaces

$ kubectl get secret <secret-name>  --namespace=<source-namespace> --export -o yaml | kubectl apply --namespace=<destination-namespace> -f -

Copy configmaps between namespaces

$ kubectl get configmap <configmap-name>  --namespace=<source-namespace> --export -o yaml | kubectl apply --namespace=<destination-namespace> -f -

Kubernetes version 1.14 and higher

Flag export have been deprecated in 1.14 Deprecate --export flag from get command #73787Instead following command can be used:

kubectl get secret <secret-name> --namespace=<source-namespace>  -o yaml | sed 's/namespace: <from-namespace>/namespace: <to-namespace>/' | kubectl create -f -

If someone still see a need for the flag, export script was written by @zoidbergwill that is doing that nicely.

Please use the following command to copy from one namespace to another

kubectl get configmap <configmap-name> -n <source-namespace> -o yaml | sed 's/namespace: <source-namespace>/namespace: <dest-namespace>/' | kubectl create -f -

kubectl get secret <secret-name> -n <source-namespace> -o yaml | sed 's/namespace: <source-namespace>/namespace: <dest-namespace>/' | kubectl create -f -