kubernetes-registry-check

DaemonSet checks ability to connect from each Kubernetes cluster node to specified registries. Results printed in json format and then could be handled by other monitoring system (f.e. FluentD to ElasticSearch).

Example of output json (preformatted):

{
	"Timestamp": "2021-02-25T09:21:56Z",
	"Source": {
		"PodName": "kubernetes-registry-check-f9w9g",
		"PodIP": "10.42.128.2",
		"HostName": "kub-test-master1",
		"HostIP": "192.168.1.101"
	},
	"Destination": "nexus.registry.contoso.com:45105",
	"Message": "{\"repositories\":[]}",
	"Success": true
}

or failed example (dns problem):

{
	"Timestamp": "2021-02-25T09:24:37Z",
	"Source": {
		"PodName": "kubernetes-registry-check-f9w9g",
		"PodIP": "10.42.128.2",
		"HostName": "kub-test-master1",
		"HostIP": "192.168.1.101"
	},
	"Destination": "nexus.registry.contoso.com:45105",
	"Message": "Get https://nexus.registry.contoso.com:45105/v2/_catalog: dial tcp: lookup nexus.registry.contoso.com on 10.43.0.10:53: read udp 10.42.128.2:38515-\u003e10.43.0.10:53: i/o timeout",
	"Success": false
}

Deployment

Current configuration deploys DaemonSet to monitoring namespace. To deploy in another namespace (f.e. kube-system) you have to modify kubernetes-registry-check.yaml.

./kubectl --server "<your k8s cluster address>" --token "<your token here>" --insecure-skip-tls-verify apply -f "kubernetes-registry-check.yaml"

Adding new registry for monitoring

./kubectl --server "<your k8s cluster address>" --token "<your token here>" --insecure-skip-tls-verify create secret docker-registry registry --namespace monitoring --docker-server="<registry address>" --docker-username="<registry user name>" --docker-password="<registry password>"

Several registries are supported.