Modifications to get flatcar working

* Move flatcar config spec into specialised define block
* generic osDistro variable to specify "flatcar" and future other OS

charts/openstack-cluster/README.md

@@ -222,3 +222,11 @@ clusterctl get kubeconfig my-cluster > kubeconfig.my-cluster
 # Use that kubeconfig to list pods on the workload cluster
 kubectl --kubeconfig=./kubeconfig.my-cluster get po -A
 ```
+
+## Flatcar
+
+To deploy clusters which use Ignition such as Flatcar, you will need to override the following setting in your local `values.yaml`:
+
+```yaml
+osDistro: flatcar 
+```

charts/openstack-cluster/templates/_helpers.tpl

@@ -203,13 +203,15 @@ files:
       # This file is created by the capi-helm-chart to ensure that its parent directory exists
     owner: root:root
     permissions: "0644"
+{{- if ne .Values.osDistro "flatcar" }}
   - path: /etc/containerd/config.toml
     content: |
       [plugins."io.containerd.grpc.v1.cri".registry]
       config_path = "/etc/containerd/certs.d"
     owner: root:root
     permissions: "0644"
     append: true
+{{- end }}
 {{- with .Values.registryMirrors }}
 {{- range $registry, $registrySpec := . }}
   - path: /etc/containerd/certs.d/{{ $registry }}/hosts.toml
@@ -275,3 +277,45 @@ Produces the spec for a KubeadmConfig object.
   include "openstack-cluster.mergeConcatMany"
 }}
 {{- end }}
+
+{{/*
+Produces the spec for an Ignition based OS specific KubeadmConfig object conditional on osDistro set to "flatcar".
+*/}}
+{{- define "openstack-cluster.flatcarKubeadmConfigSpec" -}}
+initConfiguration:
+  nodeRegistration:
+    name: ${COREOS_OPENSTACK_HOSTNAME}
+joinConfiguration:
+  nodeRegistration:
+    name: ${COREOS_OPENSTACK_HOSTNAME}
+preKubeadmCommands:
+  - export COREOS_OPENSTACK_HOSTNAME=${COREOS_OPENSTACK_HOSTNAME%.*}
+  - envsubst < /etc/kubeadm.yml > /etc/kubeadm.yml.tmp
+  - mv /etc/kubeadm.yml.tmp /etc/kubeadm.yml
+format: ignition
+ignition:
+  containerLinuxConfig:
+    additionalConfig: |
+      systemd:
+        units:
+        - name: [email protected]
+          enabled: true
+        - name: kubeadm.service
+          enabled: true
+          dropins:
+          - name: 10-flatcar.conf
+            contents: |
+              [Unit]
+              Requires=containerd.service coreos-metadata.service
+              After=containerd.service coreos-metadata.service
+              [Service]
+              EnvironmentFile=/run/metadata/flatcar
+{{- end }}
+
+{{- define "openstack-cluster.osDistroKubeadmConfigSpec" }}
+{{- $ctx := index . 0 }}
+{{- $osDistro := $ctx.Values.osDistro }}
+{{- if eq $osDistro "flatcar" }}
+{{- include "openstack-cluster.flatcarKubeadmConfigSpec" $ctx }}
+{{- end }}
+{{- end }}

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

@@ -6,9 +6,13 @@ joinConfiguration: {{ include "openstack-cluster.nodeRegistration.nodeLabels" .
 {{- end }}
 
 {{- define "openstack-cluster.controlplane.kubeadmConfigSpec.kubeProxyConfiguration" -}}
-{{- with .kubeProxyConfiguration }}
+{{- $ctx := index . 0 }}
+{{- $osDistro := index . 1 }}
+{{- $kubeProxyConfigurationPath := ternary "/etc/kube-proxy-configuration.yaml" "/run/kubeadm/kube-proxy-configuration.yaml" (eq $osDistro "flatcar") }}
+{{- $kubeadmPath := ternary "/etc/kubeadm.yml" "/run/kubeadm/kubeadm.yaml" (eq $osDistro "flatcar") }}
+{{- with $ctx.kubeProxyConfiguration }}
 files:
-  - path: /run/kubeadm/kube-proxy-configuration.yaml
+  - path: {{ $kubeProxyConfigurationPath }}
     content: |
       ---
       apiVersion: kubeproxy.config.k8s.io/v1alpha1
@@ -17,7 +21,7 @@ files:
     owner: root:root
     permissions: "0644"
 preKubeadmCommands:
-  - cat /run/kubeadm/kube-proxy-configuration.yaml >> /run/kubeadm/kubeadm.yaml
+  - cat {{ $kubeProxyConfigurationPath }} >> {{ $kubeadmPath }}
 {{- end }}
 {{- end }}
 
@@ -53,7 +57,8 @@ spec:
         list
           (include "openstack-cluster.controlplane.kubeadmConfigSpec.nodeLabels" . | fromYaml)
           (include "openstack-cluster.kubeadmConfigSpec" (list . .Values.controlPlane.kubeadmConfigSpec) | fromYaml)
-          (include "openstack-cluster.controlplane.kubeadmConfigSpec.kubeProxyConfiguration" .Values.controlPlane.kubeadmConfigSpec | fromYaml) |
+          (include "openstack-cluster.osDistroKubeadmConfigSpec" (list . ) | fromYaml)
+          (include "openstack-cluster.controlplane.kubeadmConfigSpec.kubeProxyConfiguration" (list .Values.controlPlane.kubeadmConfigSpec .Values.osDistro) | fromYaml) |
         include "openstack-cluster.mergeConcatMany" |
         fromYaml
       )

charts/openstack-cluster/templates/node-group/kubeadm-config-template.yaml

@@ -25,8 +25,9 @@ joinConfiguration: {{ include "openstack-cluster.nodeRegistration.nodeLabels" $n
 {{-
   list
     (include "openstack-cluster.nodegroup.kct.spec.nodeLabels" (list $ctx $nodeGroup) | fromYaml)
-    (include "openstack-cluster.kubeadmConfigSpec" (list $ctx $nodeGroup.kubeadmConfigSpec) | fromYaml) |
-  include "openstack-cluster.mergeConcat" |
+    (include "openstack-cluster.kubeadmConfigSpec" (list $ctx $nodeGroup.kubeadmConfigSpec) | fromYaml)
+    (omit (include "openstack-cluster.osDistroKubeadmConfigSpec" (list $ctx) | fromYaml) "initConfiguration") |
+  include "openstack-cluster.mergeConcatMany" |
   fromYaml |
   toYaml
 }}

charts/openstack-cluster/values.yaml

@@ -119,6 +119,10 @@ apiServer:
   # The port to use for the API server
   port: 6443
 
+
+# Set ignition based OS
+osDistro: ubuntu
+# Ignition Based OS specific configuration. 
 # Settings for the control plane
 controlPlane:
   # The failure domains to use for control plane nodes