Add default provider taint and taint configuration options

This allows for more specificity when setting taint tolerations for
workloads. Three new env variables are introduced:

VKUBELET_TAINT_KEY (defaults to `virtual-kubelet.io/provider`)
VKUBELET_TAINT_VALUE (defaults to provider name)
VKUBELET_TAINT_EFFECT (defaults to `NoSchedule`)

BREAKING CHANGES:
- The default taint key of `azure.com/aci` is now
  `virtual-kubelet.io/provider`.
- Specifying a custom taint key is now done via an environment variable
  rather than the `--taint` command line flag.

charts/virtual-kubelet/Chart.yaml

@@ -1,5 +1,5 @@
 name: virtual-kubelet
-version: 0.2.0
+version: 0.3.0
 appVersion: 0.3
 description: A Helm chart to install virtual kubelet inside a Kubernetes cluster.
 icon: https://avatars2.githubusercontent.com/u/34250142

charts/virtual-kubelet/templates/deployment.yaml

@@ -28,6 +28,12 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: status.podIP
+        - 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 }}
 {{- if eq .Values.provider "azure" }}
 {{- with .Values.providers.azure }}
 {{- if .loganalytics.enabled }}
@@ -73,11 +79,13 @@ spec:
 {{- end }}
         command: ["virtual-kubelet"]
         args: [
+{{- if not .Values.taint.enabled }}
+          "--disable-taint", "true",
+{{- end }}
           "--provider", "{{ required "provider is required" .Values.provider }}",
           "--namespace", "{{ .Values.monitoredNamespace }}",
           "--nodename", "{{ required "nodeName is required" .Values.nodeName }}",
-          "--os", "{{ .Values.nodeOsType }}",
-          "--taint", "{{ .Values.nodeTaint }}"
+          "--os", "{{ .Values.nodeOsType }}"
         ]
       volumes:
       - name: credentials

charts/virtual-kubelet/templates/tests/helloworld.yaml

@@ -23,5 +23,8 @@ spec:
     kubernetes.io/hostname: "{{ .Values.nodeName }}"
   restartPolicy: Never
   tolerations:
-  - key: "{{ .Values.nodeTaint }}"
-    effect: NoSchedule
+{{- if .Values.taint.enabled }}
+  - key: "{{ .Values.taint.key }}"
+    value: "{{ tpl .Values.taint.value $ }}"
+    effect: "{{ .Values.taint.effect }}"
+{{- end }}

charts/virtual-kubelet/values.yaml

@@ -6,12 +6,18 @@ image:
 ## `provider` should be one of aws, azure, azurebatch, etc...
 provider: 
 nodeName: "virtual-kubelet"
-nodeTaint: "azure.com/aci"
 nodeOsType: "Linux"
 monitoredNamespace: ""
 apiserverCert: 
 apiserverKey: 
 
+taint:
+  enabled: true
+  key: virtual-kubelet.io/provider
+  value: "{{ .Values.provider }}"
+  ## `effect` must be `NoSchedule`, `PreferNoSchedule` or `NoExecute`.
+  effect: NoSchedule
+
 providers:
   azure:
     ## Set to true if deploying to Azure Kubernetes Service (AKS), otherwise false