Resolve DNS resolution issues for Hetzner on Ubuntu 24.04

Signed-off-by: Waleed Malik <ahmedwaleedmalik@gmail.com>
kubermatic · Oct 10, 2024 · 2e60d09 · 2e60d09
1 parent bc2dc58
commit 2e60d09
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Showing 5 changed files with 12 additions and 5 deletions.
diff --git a/deploy/osps/default/osp-ubuntu.yaml b/deploy/osps/default/osp-ubuntu.yaml
@@ -19,7 +19,7 @@ metadata:
   namespace: kube-system
 spec:
   osName: "ubuntu"
-  osVersion: "20.04"
+  osVersion: "24.04"
   version: "v1.5.0"
   provisioningUtility: "cloud-init"
   supportedCloudProviders:
@@ -107,6 +107,13 @@ spec:
               {{- template "configureProxyScript" }}
               {{- template "configureHostCABundle" }}
 
+              {{- /* Starting with Ubuntu 24.04, there is an issue with DNS resolution that leaves machines without connectivity consistently. We even observed this issue on machines
+              where the netplan wasn't executed in the second cloud-init run. To fix this we are adding Cloudfare as fallback for DNS resolution */}}
+              {{- if eq .CloudProviderName "hetzner" }}
+              sed -i '/\[Resolve\]/a FallbackDNS=1.1.1.1#cloudflare-dns.com 1.0.0.1#cloudflare-dns.com 2606:4700:4700::1111#cloudflare-dns.com 2606:4700:4700::1001#cloudflare-dns.com' /etc/systemd/resolved.conf
+              systemctl restart systemd-resolved
+              {{- end }}
+
               export DEBIAN_FRONTEND=noninteractive
               apt update && apt install -y curl jq
               curl -s -k -v --header 'Authorization: Bearer {{ .Token }}'	{{ .ServerURL }}/api/v1/namespaces/cloud-init-settings/secrets/{{ .SecretName }} | jq '.data["cloud-config"]' -r| base64 -d > /etc/cloud/cloud.cfg.d/{{ .SecretName }}.cfg

diff --git a/pkg/controllers/osc/testdata/osc-kubelet-configuration-containerd.yaml b/pkg/controllers/osc/testdata/osc-kubelet-configuration-containerd.yaml
@@ -81,7 +81,7 @@ spec:
       subnetID: test-subnet
       vpcId: e-123f
   osName: ubuntu
-  osVersion: "20.04"
+  osVersion: "24.04"
   provisioningConfig:
     files:
     - content:

diff --git a/pkg/controllers/osc/testdata/osc-ubuntu-aws-containerd.yaml b/pkg/controllers/osc/testdata/osc-ubuntu-aws-containerd.yaml
@@ -81,7 +81,7 @@ spec:
       subnetID: test-subnet
       vpcId: e-123f
   osName: ubuntu
-  osVersion: "20.04"
+  osVersion: "24.04"
   provisioningConfig:
     files:
     - content:

diff --git a/pkg/controllers/osc/testdata/osc-ubuntu-aws-dualstack-IPv6+IPv4.yaml b/pkg/controllers/osc/testdata/osc-ubuntu-aws-dualstack-IPv6+IPv4.yaml
@@ -81,7 +81,7 @@ spec:
       subnetID: test-subnet
       vpcId: e-123f
   osName: ubuntu
-  osVersion: "20.04"
+  osVersion: "24.04"
   provisioningConfig:
     files:
     - content:

diff --git a/pkg/controllers/osc/testdata/osc-ubuntu-aws-dualstack.yaml b/pkg/controllers/osc/testdata/osc-ubuntu-aws-dualstack.yaml
@@ -81,7 +81,7 @@ spec:
       subnetID: test-subnet
       vpcId: e-123f
   osName: ubuntu
-  osVersion: "20.04"
+  osVersion: "24.04"
   provisioningConfig:
     files:
     - content: