Merge pull request #4350 from CecileRobertMichon/remove-ipv6-workaround

Remove DNS workaround for ipv6 templates
kubernetes-sigs · Dec 12, 2023 · 0ccc4d3 · 0ccc4d3
2 parents 7a44c7c + adf2190
commit 0ccc4d3
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Showing 15 changed files with 7 additions and 126 deletions.
diff --git a/docs/book/src/topics/ipv6.md b/docs/book/src/topics/ipv6.md
@@ -121,14 +121,6 @@ The reference [ipv6 flavor](https://raw.githubusercontent.com/kubernetes-sigs/cl
 
 - Kubernetes version needs to be 1.18+
 
-- The :53 port needs to be free on the host so coredns can use it. In 18.04, systemd-resolved uses the port :53 on the host and is used by default for DNS. This causes the coredns pods to crash for single stack IPv6 with bind address already in use as coredns pods are run on hostNetwork to leverage the host routes for DNS resolution. This is done by running the following commands in postKubeadmCommands:
-```yaml
-    - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-    - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf
-      /etc/resolv.conf
-    - systemctl restart systemd-resolved
-```
-
 - The coredns pod needs to run on the host network, so it can leverage host routes for the v4 network to do the DNS resolution. The workaround is to edit the coredns deployment and add `hostNetwork: true`:
 ```bash
 kubectl patch deploy/coredns -n kube-system --type=merge -p '{"spec": {"template": {"spec":{"hostNetwork": true}}}}'

diff --git a/templates/cluster-template-dual-stack.yaml b/templates/cluster-template-dual-stack.yaml
diff --git a/templates/cluster-template-ipv6.yaml b/templates/cluster-template-ipv6.yaml
diff --git a/templates/flavors/dual-stack/machine-deployment.yaml b/templates/flavors/dual-stack/machine-deployment.yaml
@@ -45,11 +45,6 @@ metadata:
 spec:
   template:
     spec:
-      postKubeadmCommands:
-        # This frees up :53 on the host for the coredns pods
-        - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-        - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
-        - systemctl restart systemd-resolved containerd
       joinConfiguration:
         nodeRegistration:
           name: '{{ ds.meta_data["local_hostname"] }}'

diff --git a/templates/flavors/dual-stack/patches/kubeadm-controlplane.yaml b/templates/flavors/dual-stack/patches/kubeadm-controlplane.yaml
@@ -4,11 +4,6 @@ metadata:
   name: "${CLUSTER_NAME}-control-plane"
 spec:
   kubeadmConfigSpec:
-    postKubeadmCommands:
-      # This frees up :53 on the host for the coredns pods
-      - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-      - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
-      - systemctl restart systemd-resolved containerd
     initConfiguration:
       nodeRegistration:
         name: '{{ ds.meta_data["local_hostname"] }}'

diff --git a/templates/flavors/ipv6/machine-deployment.yaml b/templates/flavors/ipv6/machine-deployment.yaml
@@ -45,11 +45,6 @@ metadata:
 spec:
   template:
     spec:
-      postKubeadmCommands:
-        # This frees up :53 on the host for the coredns pods
-        - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-        - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
-        - systemctl restart systemd-resolved containerd
       joinConfiguration:
         nodeRegistration:
           name: '{{ ds.meta_data["local_hostname"] }}'

diff --git a/templates/flavors/ipv6/patches/kubeadm-controlplane.yaml b/templates/flavors/ipv6/patches/kubeadm-controlplane.yaml
@@ -4,11 +4,6 @@ metadata:
   name: "${CLUSTER_NAME}-control-plane"
 spec:
   kubeadmConfigSpec:
-    postKubeadmCommands:
-      # This frees up :53 on the host for the coredns pods
-      - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-      - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
-      - systemctl restart systemd-resolved containerd
     initConfiguration:
       nodeRegistration:
         name: '{{ ds.meta_data["local_hostname"] }}'

diff --git a/templates/test/ci/cluster-template-prow-ci-version-dual-stack.yaml b/templates/test/ci/cluster-template-prow-ci-version-dual-stack.yaml
diff --git a/templates/test/ci/cluster-template-prow-ci-version-ipv6.yaml b/templates/test/ci/cluster-template-prow-ci-version-ipv6.yaml
diff --git a/templates/test/ci/cluster-template-prow-dual-stack.yaml b/templates/test/ci/cluster-template-prow-dual-stack.yaml
diff --git a/templates/test/ci/cluster-template-prow-ipv6.yaml b/templates/test/ci/cluster-template-prow-ipv6.yaml
diff --git a/templates/test/ci/prow-ci-version-dual-stack/patches/machine-deployment.yaml b/templates/test/ci/prow-ci-version-dual-stack/patches/machine-deployment.yaml
@@ -7,16 +7,3 @@ spec:
   template:
     spec:
       enableIPForwarding: true
----
-apiVersion: bootstrap.cluster.x-k8s.io/v1beta1
-kind: KubeadmConfigTemplate
-metadata:
-  name: "${CLUSTER_NAME}-md-0"
-spec:
-  template:
-    spec:
-      postKubeadmCommands:
-        # This frees up :53 on the host for the coredns pods
-        - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-        - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
-        - systemctl restart systemd-resolved containerd
diff --git a/templates/test/ci/prow-ci-version-ipv6/patches/machine-deployment.yaml b/templates/test/ci/prow-ci-version-ipv6/patches/machine-deployment.yaml
@@ -5,11 +5,6 @@ metadata:
 spec:
   template:
     spec:
-      postKubeadmCommands:
-        # This frees up :53 on the host for the coredns pods
-        - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-        - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
-        - systemctl restart systemd-resolved containerd
       joinConfiguration:
         nodeRegistration:
           name: '{{ ds.meta_data["local_hostname"] }}'

diff --git a/templates/test/ci/prow-dual-stack/machine-pool-dualstack.yaml b/templates/test/ci/prow-dual-stack/machine-pool-dualstack.yaml
@@ -64,8 +64,3 @@ spec:
         cloud-provider: azure
         cluster-dns: '[fd00::10]'
       name: '{{ ds.meta_data["local_hostname"] }}'
-  postKubeadmCommands:
-  - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-  - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf
-    /etc/resolv.conf
-  - systemctl restart systemd-resolved containerd
diff --git a/templates/test/ci/prow-ipv6/machine-pool-ipv6.yaml b/templates/test/ci/prow-ipv6/machine-pool-ipv6.yaml
@@ -74,8 +74,4 @@ spec:
         cloud-provider: azure
         cluster-dns: '[fd00::10]'
       name: '{{ ds.meta_data["local_hostname"] }}'
-  postKubeadmCommands:
-  - echo "DNSStubListener=no" >> /etc/systemd/resolved.conf
-  - mv /etc/resolv.conf /etc/resolv.conf.OLD && ln -s /run/systemd/resolve/resolv.conf
-    /etc/resolv.conf
-  - systemctl restart systemd-resolved containerd
+