use templates to merge default and user provided affinity

Signed-off-by: Marius Kimmina <[email protected]>
prometheus-community · Jul 24, 2024 · 18e1ef3 · 18e1ef3
1 parent 092e199
commit 18e1ef3
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Showing 4 changed files with 50 additions and 11 deletions.
diff --git a/charts/prometheus-node-exporter/templates/_helpers.tpl b/charts/prometheus-node-exporter/templates/_helpers.tpl
@@ -200,3 +200,33 @@ labelValueLengthLimit: {{ . }}
 {{- end }}
 {{- end }}
 {{- end }}
+
+{{/*
+The default node affinity to exclude Fargate nodes and merge with user-defined affinity
+*/}}
+{{- define "prometheus-node-exporter.defaultAffinity" -}}
+nodeAffinity:
+  requiredDuringSchedulingIgnoredDuringExecution:
+    nodeSelectorTerms:
+    - matchExpressions:
+      - key: eks.amazonaws.com/compute-type
+        operator: NotIn
+        values:
+        - fargate
+{{- end -}}
+{{- define "prometheus-node-exporter.mergeAffinities" -}}
+{{- $defaultAffinity := include "prometheus-node-exporter.defaultAffinity" . | fromYaml -}}
+{{- $userAffinity := .Values.affinity -}}
+{{- if and $userAffinity $userAffinity.nodeAffinity -}}
+  {{- if $userAffinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution -}}
+    {{- $defaultTerms := $defaultAffinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution.nodeSelectorTerms -}}
+    {{- $userTerms := $userAffinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution.nodeSelectorTerms -}}
+    {{- $mergedTerms := concat $defaultTerms $userTerms -}}
+    {{- $_ := set $defaultAffinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution "nodeSelectorTerms" $mergedTerms -}}
+  {{- end -}}
+  {{- $mergedNodeAffinity := merge $defaultAffinity.nodeAffinity $userAffinity.nodeAffinity -}}
+  {{- $_ := set $defaultAffinity "nodeAffinity" $mergedNodeAffinity -}}
+{{- end -}}
+{{- toYaml $defaultAffinity -}}
+{{- end -}}
+
diff --git a/charts/prometheus-node-exporter/templates/daemonset.yaml b/charts/prometheus-node-exporter/templates/daemonset.yaml
@@ -246,17 +246,7 @@ spec:
       hostNetwork: {{ .Values.hostNetwork }}
       hostPID: {{ .Values.hostPID }}
       affinity:
-        nodeAffinity:
-          requiredDuringSchedulingIgnoredDuringExecution:
-            nodeSelectorTerms:
-              - matchExpressions:
-                  - key: eks.amazonaws.com/compute-type
-                    operator: NotIn
-                    values: 
-                      - fargate
-      {{- with .Values.affinity }}
-        {{- toYaml . | nindent 8 }}
-      {{- end }}
+        {{- include "prometheus-node-exporter.mergeAffinities" . | nindent 8 }}
       {{- with .Values.dnsConfig }}
       dnsConfig:
         {{- toYaml . | nindent 8 }}

diff --git a/charts/test.yml b/charts/test.yml
@@ -0,0 +1,9 @@
+affinity:
+  nodeAffinity:
+    requiredDuringSchedulingIgnoredDuringExecution:
+      nodeSelectorTerms:
+        - matchExpressions:
+            - key: node-type
+              operator: In
+              values:
+                - compute
diff --git a/charts/test2.yml b/charts/test2.yml
@@ -0,0 +1,10 @@
+affinity:
+  nodeAffinity:
+    preferredDuringSchedulingIgnoredDuringExecution:
+      - weight: 1
+        preference:
+          matchExpressions:
+            - key: custom-key
+              operator: In
+              values:
+                - custom-value