kube-sync synchronise (create/update) a configmap from a source namespace to all namespaces.
Have a look to the docs and the examples.
kube-sync also exposes the following metrics.
kube-sync annotate the configmap with the references of the source and the update timestamp.
apiVersion: v1
kind: ConfigMap
metadata:
annotations:
kube-sync/source: '{"namespace":"kube-system","name":"to-sync","uid":"2ba4f600-883f-11e8-ae10-42010a10e004","resourceVersion":"47067967","last-update":1533203794}'./kube-sync kube-system to-sync --kubeconfig-path ~/.kube/config -v 1
I0804 14:20:26.812652 12678 kubesync.go:139] Starting to sync source cm/to-sync from ns kube-system ...
I0804 14:20:26.827481 12678 kubesync.go:166] Annotate the destination configmaps with the reference of the source kube-sync/source: {"namespace":"kube-system","name":"to-sync","uid":"c63cc178-97d4-11e8-9192-5404a66983a9","resourceVersion":"1039","last-update":1533385226}
I0804 14:20:26.827650 12678 kubesync.go:172] The configmap to sync across 4 namespaces is: {"metadata":{"name":"to-sync","namespace":"kube-system","selfLink":"/api/v1/namespaces/kube-system/configmaps/to-sync","uid":"c63cc178-97d4-11e8-9192-5404a66983a9","resourceVersion":"1039","creationTimestamp":"2018-08-04T10:54:34Z"},"data":{"bar":"two","foo":"one"}}
I0804 14:20:26.829784 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns default
I0804 14:20:26.831985 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns kube-public
I0804 14:20:26.832001 12678 kubesync.go:178] Skipping sync over the namespace kube-system: namespace of the source configmap
I0804 14:20:26.833722 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns ns-8d7f7740-1911-440b-b31c-102eb904d167
I0804 14:20:26.835222 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns ns-91e8b569-376a-4fe2-9a45-da7bde6e066a
I0804 14:20:26.835238 12678 kubesync.go:210] Successfully sync in 22.596424ms
I0804 14:20:26.835269 12678 kubesync.go:229] Starting prometheus exporter on 0.0.0.0:8484/metrics
I0804 14:20:26.835331 12678 kubesync.go:246] Starting pprof on 127.0.0.1:6060/debug/pprof
I0804 14:20:26.835341 12678 kubesync.go:267] Starting to sync every 1m0s
I0804 14:21:26.835443 12678 kubesync.go:139] Starting to sync source cm/to-sync from ns kube-system ...
I0804 14:21:26.840726 12678 kubesync.go:166] Annotate the destination configmaps with the reference of the source kube-sync/source: {"namespace":"kube-system","name":"to-sync","uid":"c63cc178-97d4-11e8-9192-5404a66983a9","resourceVersion":"1039","last-update":1533385286}
I0804 14:21:26.840787 12678 kubesync.go:172] The configmap to sync across 4 namespaces is: {"metadata":{"name":"to-sync","namespace":"kube-system","selfLink":"/api/v1/namespaces/kube-system/configmaps/to-sync","uid":"c63cc178-97d4-11e8-9192-5404a66983a9","resourceVersion":"1039","creationTimestamp":"2018-08-04T10:54:34Z"},"data":{"bar":"two","foo":"one"}}
I0804 14:21:26.844151 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns default
I0804 14:21:26.847008 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns kube-public
I0804 14:21:26.847023 12678 kubesync.go:178] Skipping sync over the namespace kube-system: namespace of the source configmap
I0804 14:21:26.849536 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns ns-8d7f7740-1911-440b-b31c-102eb904d167
I0804 14:21:26.854013 12678 kubesync.go:193] Successfully sync cm/to-sync from ns kube-system to the ns ns-91e8b569-376a-4fe2-9a45-da7bde6e066a
I0804 14:21:26.854032 12678 kubesync.go:210] Successfully sync in 18.603709ms