When you are running the IoT Edge VK provider deployed by the previous helm chart, you might have noticed the following log entry querying the virtualkubelet container logs.
kubectl logs hub0-iot-edge-connector-6b594c6444-g7mqz virtualkubelet
Flag --taint has been deprecated, Taint key should now be configured using the VK_TAINT_KEY environment variable
The process to define the taint for the virtual node, when using the Virtual Kubelet, has changed. The taint must now be defined via environment variables instead of a flag in the argument section.
This change and a couple of others have been introduced with PR 21 to the IoT Edge VK provider.
-> https://github.com/Azure/iot-edge-virtual-kubelet-provider
-> https://github.com/Azure/iot-edge-virtual-kubelet-provider/pull/21
deployment.yaml before:
...
- name: virtualkubelet
image: "{{ .Values.vkimage.repository }}:{{ .Values.vkimage.tag }}"
imagePullPolicy: {{ .Values.vkimage.pullPolicy }}
env:
- name: WEB_ENDPOINT_URL
value: http://localhost:{{ .Values.edgeproviderimage.port }}
command: ["virtual-kubelet"]
args: ["--provider", "web", "--nodename", {{ default "web-provider" .Values.env.nodeName | quote }}, "--taint", {{ default "azure.com/iotedge" .Values.env.nodeTaint | quote }}]
...
deployment.yaml after:
...
- name: virtualkubelet
image: "{{ .Values.vkimage.repository }}:{{ .Values.vkimage.tag }}"
imagePullPolicy: {{ .Values.vkimage.pullPolicy }}
env:
- name: KUBELET_PORT
value: "10250"
- name: VKUBELET_TAINT_KEY
value: {{ .Values.taint.key }}
- name: VKUBELET_TAINT_VALUE
value: {{ tpl .Values.taint.value $ }}
- name: VKUBELET_TAINT_EFFECT
value: {{ .Values.taint.effect }}
- name: WEB_ENDPOINT_URL
value: http://localhost:{{ .Values.edgeproviderimage.port }}
command: ["virtual-kubelet"]
args: [
"--provider", "{{ required "provider is required" .Values.env.provider }}",
"--namespace", "{{ .Values.env.monitoredNamespace }}",
"--nodename", "{{ required "nodeName is required" .Values.env.nodeName }}",
{{- if not .Values.taint.enabled }}
"--disable-taint", "true",
{{- end }}
"--os", "{{ .Values.env.nodeOsType }}"
]
...
values.yaml before:
... env: nodeName: iot-edge-connector-hub0 nodeTaint: ...
values.yaml after:
...env: nodeName: iot-edge-connector-hub0 nodeOsType: Linux monitoredNamespace: "" # 'provider' must be 'web' provider: web taint: enabled: true key: virtual-kubelet.io/provider value: iotedge ...
Furthermore, a nodeSelector is introduced to ensure that the IoT Edge VK Provider lands on Linux nodes only.
deployment.yaml:
...
nodeSelector:
beta.kubernetes.io/os: linux
The last thing that changed is the switch to default rbac.install to true instead of the previous false. Looking at Kubernetes best practices your Kubernetes clusters should have RBAC enabled. So, per default the IoT Edge VK provider helm chart honors this.
IoT Edge VK provider deployment on a Kubernetes cluster with RBAC enabled:
helm install -n hub0 .
IoT Edge VK provider deployment on a Kubernetes cluster with RBAC disabled:
helm install -n hub0 --set rbac.install=false .
The taint changes are introducing breaking changes to your IoT Edge deployment templates.
Before:
...
tolerations:
- key: azure.com/iotedge
effect: NoSchedule
...
After:
...
tolerations:
- key: virtual-kubelet.io/provider
operator: Equal
value: iotedge
effect: NoSchedule
...
As you can see you must update your IoT Edge deployment templates, when using the update IoT Edge VK provider helm chart for installing or updating your IoT Edge VK provider deployment.