const (
// CoreDNSService is the CoreDNS Service manifest
CoreDNSService = `
apiVersion: v1
kind: Service
metadata:
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
kubernetes.io/name: "CoreDNS"
name: kube-dns
namespace: kube-system
annotations:
prometheus.io/port: "9153"
prometheus.io/scrape: "true"
# Without this resourceVersion value, an update of the Service between versions will yield:
# Service "kube-dns" is invalid: metadata.resourceVersion: Invalid value: "": must be specified for an update
resourceVersion: "0"
spec:
clusterIP: {{ .DNSIP }}
ports:
- name: dns
port: 53
protocol: UDP
targetPort: 53
- name: dns-tcp
port: 53
protocol: TCP
targetPort: 53
- name: metrics
port: 9153
protocol: TCP
targetPort: 9153
selector:
k8s-app: kube-dns
`
// CoreDNSDeployment is the CoreDNS Deployment manifest
CoreDNSDeployment = `
apiVersion: apps/v1
kind: Deployment
metadata:
name: {{ .DeploymentName }}
namespace: kube-system
labels:
k8s-app: kube-dns
spec:
replicas: {{ .Replicas }}
strategy:
type: RollingUpdate
rollingUpdate:
maxUnavailable: 1
selector:
matchLabels:
k8s-app: kube-dns
template:
metadata:
labels:
k8s-app: kube-dns
spec:
priorityClassName: system-cluster-critical
serviceAccountName: coredns
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
- key: k8s-app
operator: In
values: ["kube-dns"]
topologyKey: kubernetes.io/hostname
tolerations:
- key: CriticalAddonsOnly
operator: Exists
- key: {{ .ControlPlaneTaintKey }}
effect: NoSchedule
nodeSelector:
kubernetes.io/os: linux
containers:
- name: coredns
image: {{ .Image }}
imagePullPolicy: IfNotPresent
resources:
limits:
memory: 170Mi
requests:
cpu: 100m
memory: 70Mi
args: [ "-conf", "/etc/coredns/Corefile" ]
volumeMounts:
- name: config-volume
mountPath: /etc/coredns
readOnly: true
ports:
- containerPort: 53
name: dns
protocol: UDP
- containerPort: 53
name: dns-tcp
protocol: TCP
- containerPort: 9153
name: metrics
protocol: TCP
livenessProbe:
httpGet:
path: /health
port: 8080
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
readinessProbe:
httpGet:
path: /ready
port: 8181
scheme: HTTP
securityContext:
allowPrivilegeEscalation: false
capabilities:
add:
- NET_BIND_SERVICE
drop:
- ALL
readOnlyRootFilesystem: true
dnsPolicy: Default
volumes:
- name: config-volume
configMap:
name: coredns
items:
- key: Corefile
path: Corefile
`
// CoreDNSConfigMap is the CoreDNS ConfigMap manifest
CoreDNSConfigMap = `
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns
namespace: kube-system
data:
Corefile: |
.:53 {
errors
health {
lameduck 5s
}
ready
kubernetes {{ .DNSDomain }} in-addr.arpa ip6.arpa {
pods insecure
fallthrough in-addr.arpa ip6.arpa
ttl 30
}
prometheus :9153
forward . /etc/resolv.conf {
max_concurrent 1000
}
cache 30
loop
reload
loadbalance
}
`
// CoreDNSClusterRole is the CoreDNS ClusterRole manifest
CoreDNSClusterRole = `
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: system:coredns
rules:
- apiGroups:
- ""
resources:
- endpoints
- services
- pods
- namespaces
verbs:
- list
- watch
- apiGroups:
- discovery.k8s.io
resources:
- endpointslices
verbs:
- list
- watch
`
// CoreDNSClusterRoleBinding is the CoreDNS Clusterrolebinding manifest
CoreDNSClusterRoleBinding = `
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: system:coredns
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:coredns
subjects:
- kind: ServiceAccount
name: coredns
namespace: kube-system
`
// CoreDNSServiceAccount is the CoreDNS ServiceAccount manifest
CoreDNSServiceAccount = `
apiVersion: v1
kind: ServiceAccount
metadata:
name: coredns
namespace: kube-system
`
)
func DeployedDNSAddon(client clientset.Interface) (string, error)
DeployedDNSAddon returns the image tag of the DNS addon currently deployed
func EnsureDNSAddon(cfg *kubeadmapi.ClusterConfiguration, client clientset.Interface, out io.Writer, printManifest bool) error
EnsureDNSAddon creates the CoreDNS addon
func GetCoreDNSInfo(client clientset.Interface) (*v1.ConfigMap, string, string, error)
GetCoreDNSInfo gets the current CoreDNS installed and the current Corefile Configuration of CoreDNS.