Enable parallel image pulls (#21)

As of 1.27, Kubernetes added support for parallelizing image pulls but
this is not enabled by default.  This is especially useful in situations
where multiple images need to be downloaded to a host, but one of them
is particularly large.

charts/cluster-api-cluster-openstack/Chart.yaml

@@ -2,5 +2,5 @@ apiVersion: v2
 name: cluster-api-cluster-openstack
 description: A Helm chart to deploy a Kubernetes Cluster
 type: application
-version: v0.5.6
+version: v0.5.7
 icon: https://raw.githubusercontent.com/unikorn-cloud/helm-cluster-api/main/icons/default.png

charts/cluster-api-cluster-openstack/README.md

@@ -36,7 +36,7 @@ spec:
   source:
     repoURL: https://unikorn-cloud.github.io/helm-cluster-api
     chart: cluster-api-cluster-openstack
-    targetRevision: v0.5.6
+    targetRevision: v0.5.7
     helm:
       releaseName: foo
       # Remove the default work queue.

charts/cluster-api-cluster-openstack/templates/control-plane.yaml

@@ -29,6 +29,8 @@ spec:
       skipPhases:
         {{- toYaml $.Values.controlPlane.kubeadmSkipPhases | nindent 6 }}
       {{- end }}
+      patches:
+        directory: /etc/kubernetes/patches
     joinConfiguration:
       nodeRegistration:
         name: {{ "'{{ local_hostname }}'" }}
@@ -37,6 +39,8 @@ spec:
           node-labels: {{- include "openstack.nodelabels.control-plane" . | nindent 12 }}
         taints:
           {{- include "openstack.taints.control-plane" . | nindent 8 }}
+      patches:
+        directory: /etc/kubernetes/patches
     clusterConfiguration:
       apiServer:
         extraArgs:
@@ -63,6 +67,16 @@ spec:
         extraArgs:
           authorization-always-allow-paths: "/healthz,/readyz,/livez,/metrics"
           bind-address: "0.0.0.0"
+    files:
+    {{- with $config := .Values.controlPlane.kubelet -}}
+    {{ $_ := set $config "apiVersion" "kubelet.config.k8s.io/v1beta1" -}}
+    {{ $_ := set $config "kind" "KubeletConfiguration" }}
+    - path: /etc/kubernetes/patches/kubeletconfiguration0+strategic.json
+      owner: "root:root"
+      permissions: "0644"
+      content: |
+        {{ $config | toJson }}
+    {{- end }}
 ---
 apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
 kind: OpenStackMachineTemplate

charts/cluster-api-cluster-openstack/templates/workload.yaml

@@ -107,6 +107,15 @@ spec:
         path: {{ $file.path }}
         permissions: "0600"
       {{- end }}
+      {{- with $config := $pool.kubelet -}}
+      {{ $_ := set $config "apiVersion" "kubelet.config.k8s.io/v1beta1" -}}
+      {{ $_ := set $config "kind" "KubeletConfiguration" }}
+      - path: /etc/kubernetes/patches/kubeletconfiguration0+strategic.json
+        owner: "root:root"
+        permissions: "0644"
+        content: |
+          {{ $config | toJson }}
+      {{- end }}
       joinConfiguration:
         nodeRegistration:
           name: {{ "'{{ local_hostname }}'" }}
@@ -115,4 +124,8 @@ spec:
             node-labels: {{- include "openstack.nodelabels.workload" $context | nindent 14 }}
           taints:
             {{- include "openstack.taints.workload" $ | nindent 10 }}
+        {{- if $pool.kubelet }}
+        patches:
+          directory: /etc/kubernetes/patches
+        {{- end }}
 {{- end }}

charts/cluster-api-cluster-openstack/values.yaml

@@ -98,6 +98,10 @@ controlPlane:
     # Set the server group of the control plane (e.g. anti-affinity rules).
     # serverGroupID: foo
 
+  # Any additional configuration to be passed to the kubelet can be specifed here
+  kubelet:
+    serializeImagePulls: false
+
 # Workload pools topology.
 # workloadPools:
 #  # Pool name
@@ -138,6 +142,11 @@ controlPlane:
 #    - path: /etc/cat
 #      content: bWVvdw==
 #
+#    # Additional configuration to be passed to the kubelet can be specifed here
+#    kubelet:
+#      # For example:
+#      serializeImagePulls: false
+#
 #    # Enable or disable cluster autoscaling.
 #    # This object is considered immutable.
 #    autoscaling: