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Merge pull request #2462 from woopstar/coredns-patch

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Add CoreDNS support
This commit is contained in:
Chad Swenson 2018-03-16 18:33:36 -05:00 committed by GitHub
commit 7d33650019
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20 changed files with 365 additions and 66 deletions
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8
docs/dns-stack.md
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@ -62,6 +62,14 @@ other queries are forwardet to the nameservers found in ``upstream_dns_servers``
This does not install the dnsmasq DaemonSet and instructs kubelet to directly use kubedns/skydns for
all queries.
#### coredns
This does not install the dnsmasq DaemonSet and instructs kubelet to directly use CoreDNS for
all queries.
#### coredns_dual
This does not install the dnsmasq DaemonSet and instructs kubelet to directly use CoreDNS for
all queries. It will also deploy a secondary CoreDNS stack
#### manual
This does not install dnsmasq or kubedns, but allows you to specify
`manual_dns_server`, which will be configured on nodes for handling Pod DNS.

7
docs/vars.md
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@ -63,7 +63,8 @@ following default cluster paramters:
bits in kube_pods_subnet dictates how many kube-nodes can be in cluster.
* *dns_setup* - Enables dnsmasq
* *dnsmasq_dns_server* - Cluster IP for dnsmasq (default is 10.233.0.2)
* *skydns_server* - Cluster IP for KubeDNS (default is 10.233.0.3)
* *skydns_server* - Cluster IP for DNS (default is 10.233.0.3)
* *skydns_server_secondary* - Secondary Cluster IP for CoreDNS used with coredns_dual deployment (default is 10.233.0.4)
* *cloud_provider* - Enable extra Kubelet option if operating inside GCE or
OpenStack (default is unset)
* *kube_hostpath_dynamic_provisioner* - Required for use of PetSets type in
@ -105,9 +106,9 @@ Stack](https://github.com/kubernetes-incubator/kubespray/blob/master/docs/dns-st
* *http_proxy/https_proxy/no_proxy* - Proxy variables for deploying behind a
proxy. Note that no_proxy defaults to all internal cluster IPs and hostnames
that correspond to each node.
* *kubelet_deployment_type* - Controls which platform to deploy kubelet on.
* *kubelet_deployment_type* - Controls which platform to deploy kubelet on.
Available options are ``host``, ``rkt``, and ``docker``. ``docker`` mode
is unlikely to work on newer releases. Starting with Kubernetes v1.7
is unlikely to work on newer releases. Starting with Kubernetes v1.7
series, this now defaults to ``host``. Before v1.7, the default was Docker.
This is because of cgroup [issues](https://github.com/kubernetes/kubernetes/issues/43704).
* *kubelet_load_modules* - For some things, kubelet needs to load kernel modules. For example,

3
inventory/sample/group_vars/k8s-cluster.yml
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@ -121,7 +121,7 @@ kube_encrypt_secret_data: false
cluster_name: cluster.local
# Subdomains of DNS domain to be resolved via /etc/resolv.conf for hostnet pods
ndots: 2
# Can be dnsmasq_kubedns, kubedns, manual or none
# Can be dnsmasq_kubedns, kubedns, coredns, coredns_dual, manual or none
dns_mode: kubedns
# Set manual server if using a custom cluster DNS server
#manual_dns_server: 10.x.x.x
@ -132,6 +132,7 @@ resolvconf_mode: docker_dns
deploy_netchecker: false
# Ip address of the kubernetes skydns service
skydns_server: "{{ kube_service_addresses|ipaddr('net')|ipaddr(3)|ipaddr('address') }}"
skydns_server_secondary: "{{ kube_service_addresses|ipaddr('net')|ipaddr(4)|ipaddr('address') }}"
dnsmasq_dns_server: "{{ kube_service_addresses|ipaddr('net')|ipaddr(2)|ipaddr('address') }}"
dns_domain: "{{ cluster_name }}"

6
roles/docker/tasks/set_facts_dns.yml
View file

@ -3,8 +3,10 @@
- name: set dns server for docker
set_fact:
docker_dns_servers: |-
{%- if dns_mode == 'kubedns' -%}
{%- if dns_mode in ['kubedns', 'coredns'] -%}
{{ [ skydns_server ] }}
{%- elif dns_mode == 'coredns_dual' -%}
{{ [ skydns_server ] + [ skydns_server_secondary ] }}
{%- elif dns_mode == 'dnsmasq_kubedns' -%}
{{ [ dnsmasq_dns_server ] }}
{%- elif dns_mode == 'manual' -%}
@ -24,7 +26,7 @@
- name: add upstream dns servers (only when dnsmasq is not used)
set_fact:
docker_dns_servers: "{{ docker_dns_servers + upstream_dns_servers|default([]) }}"
when: dns_mode == 'kubedns'
when: dns_mode in ['kubedns', 'coredns', 'coreos_dual']
- name: add global searchdomains
set_fact:

17
roles/download/defaults/main.yml
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@ -100,6 +100,9 @@ dnsmasq_image_tag: "{{ dnsmasq_version }}"
kubedns_version: 1.14.8
kubedns_image_repo: "gcr.io/google_containers/k8s-dns-kube-dns-amd64"
kubedns_image_tag: "{{ kubedns_version }}"
coredns_version: 1.1.0
coredns_image_repo: "docker.io/coredns/coredns"
coredns_image_tag: "{{ coredns_version }}"
dnsmasq_nanny_image_repo: "gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64"
dnsmasq_nanny_image_tag: "{{ kubedns_version }}"
dnsmasq_sidecar_image_repo: "gcr.io/google_containers/k8s-dns-sidecar-amd64"
@ -274,25 +277,31 @@ downloads:
tag: "{{ dnsmasq_image_tag }}"
sha256: "{{ dnsmasq_digest_checksum|default(None) }}"
kubedns:
enabled: true
enabled: "{{ dns_mode in ['kubedns', 'dnsmasq_kubedns'] }}"
container: true
repo: "{{ kubedns_image_repo }}"
tag: "{{ kubedns_image_tag }}"
sha256: "{{ kubedns_digest_checksum|default(None) }}"
coredns:
enabled: "{{ dns_mode in ['coredns', 'coredns_dual'] }}"
container: true
repo: "{{ coredns_image_repo }}"
tag: "{{ coredns_image_tag }}"
sha256: "{{ coredns_digest_checksum|default(None) }}"
dnsmasq_nanny:
enabled: true
enabled: "{{ dns_mode in ['kubedns', 'dnsmasq_kubedns'] }}"
container: true
repo: "{{ dnsmasq_nanny_image_repo }}"
tag: "{{ dnsmasq_nanny_image_tag }}"
sha256: "{{ dnsmasq_nanny_digest_checksum|default(None) }}"
dnsmasq_sidecar:
enabled: true
enabled: "{{ dns_mode in ['kubedns', 'dnsmasq_kubedns'] }}"
container: true
repo: "{{ dnsmasq_sidecar_image_repo }}"
tag: "{{ dnsmasq_sidecar_image_tag }}"
sha256: "{{ dnsmasq_sidecar_digest_checksum|default(None) }}"
kubednsautoscaler:
enabled: true
enabled: "{{ dns_mode in ['kubedns', 'dnsmasq_kubedns'] }}"
container: true
repo: "{{ kubednsautoscaler_image_repo }}"
tag: "{{ kubednsautoscaler_image_tag }}"

3
roles/kubernetes-apps/ansible/defaults/main.yml
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@ -10,6 +10,9 @@ dns_memory_requests: 70Mi
kubedns_min_replicas: 2
kubedns_nodes_per_replica: 10
# CoreDNS
coredns_replicas: 2
# Images
kubedns_image_repo: "gcr.io/google_containers/k8s-dns-kube-dns-amd64"
kubedns_image_tag: "{{ kubedns_version }}"

54
roles/kubernetes-apps/ansible/tasks/cleanup_dns.yml Normal file
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@ -0,0 +1,54 @@
---
- name: Kubernetes Apps | Delete old CoreDNS resources
kube:
name: "coredns"
namespace: "{{ system_namespace }}"
kubectl: "{{ bin_dir }}/kubectl"
resource: "{{ item }}"
state: absent
with_items:
- 'deploy'
- 'configmap'
- 'svc'
tags:
- upgrade
- name: Kubernetes Apps | Delete kubeadm CoreDNS
kube:
name: "coredns"
namespace: "{{ system_namespace }}"
kubectl: "{{ bin_dir }}/kubectl"
resource: "deploy"
state: absent
when:
- kubeadm_enabled|default(false)
- kubeadm_init.changed|default(false)
- inventory_hostname == groups['kube-master'][0]
- name: Kubernetes Apps | Delete old KubeDNS resources
kube:
name: "kube-dns"
namespace: "{{ system_namespace }}"
kubectl: "{{ bin_dir }}/kubectl"
resource: "{{ item }}"
state: absent
with_items:
- 'deploy'
- 'svc'
tags:
- upgrade
- name: Kubernetes Apps | Delete kubeadm KubeDNS
kube:
name: "kube-dns"
namespace: "{{ system_namespace }}"
kubectl: "{{ bin_dir }}/kubectl"
resource: "{{ item }}"
state: absent
with_items:
- 'deploy'
- 'svc'
when:
- kubeadm_enabled|default(false)
- kubeadm_init.changed|default(false)
- inventory_hostname == groups['kube-master'][0]

39
roles/kubernetes-apps/ansible/tasks/coredns.yml Normal file
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@ -0,0 +1,39 @@
---
- name: Kubernetes Apps | Lay Down CoreDNS Template
template:
src: "{{ item.file }}.j2"
dest: "{{ kube_config_dir }}/{{ item.file }}"
with_items:
- { name: coredns, file: coredns-config.yml, type: configmap }
- { name: coredns, file: coredns-sa.yml, type: sa }
- { name: coredns, file: coredns-deployment.yml, type: deployment }
- { name: coredns, file: coredns-svc.yml, type: svc }
- { name: coredns, file: coredns-clusterrole.yml, type: clusterrole }
- { name: coredns, file: coredns-clusterrolebinding.yml, type: clusterrolebinding }
register: coredns_manifests
vars:
clusterIP: "{{ skydns_server }}"
when:
- dns_mode in ['coredns', 'coredns_dual']
- inventory_hostname == groups['kube-master'][0]
- rbac_enabled or item.type not in rbac_resources
tags:
- coredns
- name: Kubernetes Apps | Lay Down Secondary CoreDNS Template
template:
src: "{{ item.src }}.j2"
dest: "{{ kube_config_dir }}/{{ item.file }}"
with_items:
- { name: coredns, src: coredns-deployment.yml, file: coredns-deployment-secondary.yml, type: deployment }
- { name: coredns, src: coredns-svc.yml, file: coredns-svc-secondary.yml, type: svc }
register: coredns_secondary_manifests
vars:
clusterIP: "{{ skydns_server_secondary }}"
coredns_ordinal_suffix: "-secondary"
when:
- dns_mode == 'coredns_dual'
- inventory_hostname == groups['kube-master'][0]
- rbac_enabled or item.type not in rbac_resources
tags:
- coredns

41
roles/kubernetes-apps/ansible/tasks/kubedns.yml Normal file
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@ -0,0 +1,41 @@
---
- name: Kubernetes Apps | Lay Down KubeDNS Template
template:
src: "{{ item.file }}.j2"
dest: "{{ kube_config_dir }}/{{ item.file }}"
with_items:
- { name: kube-dns, file: kubedns-sa.yml, type: sa }
- { name: kube-dns, file: kubedns-deploy.yml, type: deployment }
- { name: kube-dns, file: kubedns-svc.yml, type: svc }
- { name: kubedns-autoscaler, file: kubedns-autoscaler-sa.yml, type: sa }
- { name: kubedns-autoscaler, file: kubedns-autoscaler-clusterrole.yml, type: clusterrole }
- { name: kubedns-autoscaler, file: kubedns-autoscaler-clusterrolebinding.yml, type: clusterrolebinding }
- { name: kubedns-autoscaler, file: kubedns-autoscaler.yml, type: deployment }
register: kubedns_manifests
when:
- dns_mode in ['kubedns','dnsmasq_kubedns']
- inventory_hostname == groups['kube-master'][0]
- rbac_enabled or item.type not in rbac_resources
tags:
- dnsmasq
# see https://github.com/kubernetes/kubernetes/issues/45084, only needed for "old" kube-dns
- name: Kubernetes Apps | Patch system:kube-dns ClusterRole
command: >
{{ bin_dir }}/kubectl patch clusterrole system:kube-dns
--patch='{
"rules": [
{
"apiGroups" : [""],
"resources" : ["endpoints", "services"],
"verbs": ["list", "watch", "get"]
}
]
}'
when:
- dns_mode in ['kubedns', 'dnsmasq_kubedns']
- inventory_hostname == groups['kube-master'][0]
- rbac_enabled and kubedns_version|version_compare("1.11.0", "<", strict=True)
tags:
- dnsmasq

69
roles/kubernetes-apps/ansible/tasks/main.yml
View file

@ -11,66 +11,26 @@
delay: 2
when: inventory_hostname == groups['kube-master'][0]
- name: Kubernetes Apps | Delete old kubedns resources
kube:
name: "kubedns"
namespace: "{{ system_namespace }}"
kubectl: "{{ bin_dir }}/kubectl"
resource: "{{ item }}"
state: absent
with_items:
- 'deploy'
- 'svc'
- name: Kubernetes Apps | Cleanup DNS
import_tasks: tasks/cleanup_dns.yml
when:
- inventory_hostname == groups['kube-master'][0]
tags:
- upgrade
- name: Kubernetes Apps | Delete kubeadm kubedns
kube:
name: "kubedns"
namespace: "{{ system_namespace }}"
kubectl: "{{ bin_dir }}/kubectl"
resource: "deploy"
state: absent
- name: Kubernetes Apps | CoreDNS
import_tasks: "tasks/coredns.yml"
when:
- kubeadm_enabled|default(false)
- kubeadm_init.changed|default(false)
- dns_mode in ['coredns', 'coredns_dual']
- inventory_hostname == groups['kube-master'][0]
- name: Kubernetes Apps | Lay Down KubeDNS Template
template:
src: "{{ item.file }}.j2"
dest: "{{ kube_config_dir }}/{{ item.file }}"
with_items:
- { name: kube-dns, file: kubedns-sa.yml, type: sa }
- { name: kube-dns, file: kubedns-deploy.yml, type: deployment }
- { name: kube-dns, file: kubedns-svc.yml, type: svc }
- { name: kubedns-autoscaler, file: kubedns-autoscaler-sa.yml, type: sa }
- { name: kubedns-autoscaler, file: kubedns-autoscaler-clusterrole.yml, type: clusterrole }
- { name: kubedns-autoscaler, file: kubedns-autoscaler-clusterrolebinding.yml, type: clusterrolebinding }
- { name: kubedns-autoscaler, file: kubedns-autoscaler.yml, type: deployment }
register: manifests
when:
- dns_mode != 'none' and inventory_hostname == groups['kube-master'][0]
- rbac_enabled or item.type not in rbac_resources
tags:
- dnsmasq
- coredns
# see https://github.com/kubernetes/kubernetes/issues/45084, only needed for "old" kube-dns
- name: Kubernetes Apps | Patch system:kube-dns ClusterRole
command: >
{{ bin_dir }}/kubectl patch clusterrole system:kube-dns
--patch='{
"rules": [
{
"apiGroups" : [""],
"resources" : ["endpoints", "services"],
"verbs": ["list", "watch", "get"]
}
]
}'
- name: Kubernetes Apps | KubeDNS
import_tasks: "tasks/kubedns.yml"
when:
- dns_mode != 'none' and inventory_hostname == groups['kube-master'][0]
- rbac_enabled and kubedns_version|version_compare("1.11.0", "<", strict=True)
- dns_mode in ['kubedns', 'dnsmasq_kubedns']
- inventory_hostname == groups['kube-master'][0]
tags:
- dnsmasq
@ -82,7 +42,10 @@
resource: "{{ item.item.type }}"
filename: "{{ kube_config_dir }}/{{ item.item.file }}"
state: "latest"
with_items: "{{ manifests.results }}"
with_items:
- "{{ kubedns_manifests.results | default({}) }}"
- "{{ coredns_manifests.results | default({}) }}"
- "{{ coredns_secondary_manifests.results | default({}) }}"
when:
- dns_mode != 'none'
- inventory_hostname == groups['kube-master'][0]

19
roles/kubernetes-apps/ansible/templates/coredns-clusterrole.yml.j2 Normal file
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@ -0,0 +1,19 @@
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
labels:
kubernetes.io/bootstrapping: rbac-defaults
addonmanager.kubernetes.io/mode: Reconcile
name: system:coredns
rules:
- apiGroups:
- ""
resources:
- endpoints
- services
- pods
- namespaces
verbs:
- list
- watch

18
roles/kubernetes-apps/ansible/templates/coredns-clusterrolebinding.yml.j2 Normal file
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@ -0,0 +1,18 @@
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
annotations:
rbac.authorization.kubernetes.io/autoupdate: "true"
labels:
kubernetes.io/bootstrapping: rbac-defaults
addonmanager.kubernetes.io/mode: EnsureExists
name: system:coredns
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:coredns
subjects:
- kind: ServiceAccount
name: coredns
namespace: {{ system_namespace }}

22
roles/kubernetes-apps/ansible/templates/coredns-config.yml.j2 Normal file
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@ -0,0 +1,22 @@
---
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns
namespace: {{ system_namespace }}
labels:
addonmanager.kubernetes.io/mode: EnsureExists
data:
Corefile: |
.:53 {
errors
health
kubernetes {{ cluster_name }} in-addr.arpa ip6.arpa {
pods insecure
upstream /etc/resolv.conf
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
proxy . /etc/resolv.conf
cache 30
}

81
roles/kubernetes-apps/ansible/templates/coredns-deployment.yml.j2 Normal file
View file

@ -0,0 +1,81 @@
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: coredns{{ coredns_ordinal_suffix | default('') }}
namespace: {{ system_namespace }}
labels:
k8s-app: coredns{{ coredns_ordinal_suffix | default('') }}
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
kubernetes.io/name: "CoreDNS"
spec:
replicas: {{ coredns_replicas }}
strategy:
type: RollingUpdate
rollingUpdate:
maxUnavailable: 0
maxSurge: 10%
selector:
matchLabels:
k8s-app: coredns{{ coredns_ordinal_suffix | default('') }}
template:
metadata:
labels:
k8s-app: coredns{{ coredns_ordinal_suffix | default('') }}
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
{% if rbac_enabled %}
serviceAccountName: coredns
{% endif %}
tolerations:
- key: node-role.kubernetes.io/master
effect: NoSchedule
- key: "CriticalAddonsOnly"
operator: "Exists"
containers:
- name: coredns
image: "{{ coredns_image_repo }}:{{ coredns_image_tag }}"
imagePullPolicy: {{ k8s_image_pull_policy }}
resources:
# TODO: Set memory limits when we've profiled the container for large
# clusters, then set request = limit to keep this container in
# guaranteed class. Currently, this container falls into the
# "burstable" category so the kubelet doesn't backoff from restarting it.
limits:
memory: {{ dns_memory_limit }}
requests:
cpu: {{ dns_cpu_requests }}
memory: {{ dns_memory_requests }}
args: [ "-conf", "/etc/coredns/Corefile" ]
volumeMounts:
- name: config-volume
mountPath: /etc/coredns
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
dnsPolicy: Default
volumes:
- name: config-volume
configMap:
name: coredns
items:
- key: Corefile
path: Corefile

9
roles/kubernetes-apps/ansible/templates/coredns-sa.yml.j2 Normal file
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@ -0,0 +1,9 @@
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: coredns
namespace: {{ system_namespace }}
labels:
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile

22
roles/kubernetes-apps/ansible/templates/coredns-svc.yml.j2 Normal file
View file

@ -0,0 +1,22 @@
---
apiVersion: v1
kind: Service
metadata:
name: coredns{{ coredns_ordinal_suffix | default('') }}
namespace: {{ system_namespace }}
labels:
k8s-app: coredns{{ coredns_ordinal_suffix | default('') }}
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
kubernetes.io/name: "CoreDNS"
spec:
selector:
k8s-app: coredns{{ coredns_ordinal_suffix | default('') }}
clusterIP: {{ clusterIP }}
ports:
- name: dns
port: 53
protocol: UDP
- name: dns-tcp
port: 53
protocol: TCP

4
roles/kubernetes/node/templates/kubelet.kubeadm.env.j2
View file

@ -51,8 +51,10 @@ KUBELET_HOSTNAME="--hostname-override={{ kube_override_hostname }}"
{% endif %}
{# DNS settings for kubelet #}
{% if dns_mode == 'kubedns' %}
{% if dns_mode in ['kubedns', 'coredns'] %}
{% set kubelet_args_cluster_dns %}--cluster-dns={{ skydns_server }}{% endset %}
{% elif dns_mode == 'coredns_dual' %}
{% set kubelet_args_cluster_dns %}--cluster-dns={{ skydns_server }},{{ skydns_server_secondary }}{% endset %}
{% elif dns_mode == 'dnsmasq_kubedns' %}
{% set kubelet_args_cluster_dns %}--cluster-dns={{ dnsmasq_dns_server }}{% endset %}
{% elif dns_mode == 'manual' %}

4
roles/kubernetes/node/templates/kubelet.standard.env.j2
View file

@ -42,8 +42,10 @@ KUBELET_HOSTNAME="--hostname-override={{ kube_override_hostname }}"
--enforce-node-allocatable={{ kubelet_enforce_node_allocatable }} {% endif %}{% endset %}
{# DNS settings for kubelet #}
{% if dns_mode == 'kubedns' %}
{% if dns_mode in ['kubedns', 'coredns'] %}
{% set kubelet_args_cluster_dns %}--cluster-dns={{ skydns_server }}{% endset %}
{% elif dns_mode == 'coredns_dual' %}
{% set kubelet_args_cluster_dns %}--cluster-dns={{ skydns_server }},{{ skydns_server_secondary }}{% endset %}
{% elif dns_mode == 'dnsmasq_kubedns' %}
{% set kubelet_args_cluster_dns %}--cluster-dns={{ dnsmasq_dns_server }}{% endset %}
{% elif dns_mode == 'manual' %}

4
roles/kubernetes/preinstall/tasks/set_resolv_facts.yml
View file

@ -93,8 +93,10 @@
- name: pick dnsmasq cluster IP or default resolver
set_fact:
dnsmasq_server: |-
{%- if dns_mode == 'kubedns' and not dns_early|bool -%}
{%- if dns_mode in ['kubedns', 'coredns'] and not dns_early|bool -%}
{{ [ skydns_server ] + upstream_dns_servers|default([]) }}
{%- elif dns_mode == 'coredns_dual' and not dns_early|bool -%}
{{ [ skydns_server ] + [ skydns_server_secondary ] + upstream_dns_servers|default([]) }}
{%- elif dns_mode == 'manual' and not dns_early|bool -%}
{{ [ manual_dns_server ] + upstream_dns_servers|default([]) }}
{%- elif dns_early|bool -%}

1
roles/kubespray-defaults/defaults/main.yaml
View file

@ -49,6 +49,7 @@ resolvconf_mode: docker_dns
deploy_netchecker: false
# Ip address of the kubernetes skydns service
skydns_server: "{{ kube_service_addresses|ipaddr('net')|ipaddr(3)|ipaddr('address') }}"
skydns_server_secondary: "{{ kube_service_addresses|ipaddr('net')|ipaddr(4)|ipaddr('address') }}"
dnsmasq_dns_server: "{{ kube_service_addresses|ipaddr('net')|ipaddr(2)|ipaddr('address') }}"
dns_domain: "{{ cluster_name }}"