CP-48316: Let chart pods reserve ephemeral storage

app/functions/helmless/default-values.yaml

@@ -1749,6 +1749,12 @@ aggregator:
       # Whether to enable the emptyDir volume for the aggregator.
       enabled: true
       # Size limit for the emptyDir volume. If not set, no limit is applied.
+      #
+      # When set, this is also used as the collector container's
+      # ephemeral-storage request, so the pod is only scheduled onto a node
+      # with enough allocatable ephemeral storage. Set
+      # components.aggregator.collector.resources.requests.ephemeral-storage
+      # to override it.
       sizeLimit: ""
   # Configuration for the collector component of the aggregator.
   collector:

helm/templates/_helpers.tpl

@@ -1345,28 +1345,15 @@ Example usage:
 {{- if . -}}
   {{- $resources := . -}}
   {{- $cleanResources := dict -}}
-  {{- if $resources.requests -}}
-    {{- $cleanRequests := dict -}}
-    {{- if and $resources.requests.cpu (ne $resources.requests.cpu "") -}}
-      {{- $_ := set $cleanRequests "cpu" $resources.requests.cpu -}}
-    {{- end -}}
-    {{- if and $resources.requests.memory (ne $resources.requests.memory "") -}}
-      {{- $_ := set $cleanRequests "memory" $resources.requests.memory -}}
-    {{- end -}}
-    {{- if $cleanRequests -}}
-      {{- $_ := set $cleanResources "requests" $cleanRequests -}}
-    {{- end -}}
-  {{- end -}}
-  {{- if $resources.limits -}}
-    {{- $cleanLimits := dict -}}
-    {{- if and $resources.limits.cpu (ne $resources.limits.cpu "") -}}
-      {{- $_ := set $cleanLimits "cpu" $resources.limits.cpu -}}
-    {{- end -}}
-    {{- if and $resources.limits.memory (ne $resources.limits.memory "") -}}
-      {{- $_ := set $cleanLimits "memory" $resources.limits.memory -}}
+  {{- range $section := list "requests" "limits" -}}
+    {{- $clean := dict -}}
+    {{- range $name, $value := (index $resources $section | default dict) -}}
+      {{- if and $value (ne (toString $value) "") -}}
+        {{- $_ := set $clean $name $value -}}
+      {{- end -}}
     {{- end -}}
-    {{- if $cleanLimits -}}
-      {{- $_ := set $cleanResources "limits" $cleanLimits -}}
+    {{- if $clean -}}
+      {{- $_ := set $cleanResources $section $clean -}}
     {{- end -}}
   {{- end -}}
   {{- if $cleanResources -}}

helm/templates/aggregator-deploy.yaml

@@ -115,10 +115,24 @@ spec:
             initialDelaySeconds: {{ $collectorLiveness.initialDelaySeconds }}
             periodSeconds: {{ $collectorLiveness.periodSeconds }}
             failureThreshold: {{ $collectorLiveness.failureThreshold }}
-          {{- include "cloudzero-agent.generateResources" (include "cloudzero-agent.mergeStringOverwrite" (list
+          {{- $collectorResources := include "cloudzero-agent.mergeStringOverwrite" (list
               (.Values.components.aggregator.collector.resources | default (dict))
               (.Values.aggregator.collector.resources | default (dict))
-            ) | fromYaml) | nindent 10 }}
+            ) | fromYaml -}}
+          {{- /*
+          The collector writes the metric files to the shared emptyDir, so when a
+          sizeLimit is set, reserve that much ephemeral storage for scheduling
+          unless the collector requests ephemeral storage explicitly.
+          */}}
+          {{- $emptyDir := .Values.aggregator.database.emptyDir }}
+          {{- if and $emptyDir.enabled $emptyDir.sizeLimit }}
+            {{- $requests := $collectorResources.requests | default (dict) }}
+            {{- if not (index $requests "ephemeral-storage") }}
+              {{- $_ := set $requests "ephemeral-storage" $emptyDir.sizeLimit }}
+              {{- $_ := set $collectorResources "requests" $requests }}
+            {{- end }}
+          {{- end }}
+          {{- include "cloudzero-agent.generateResources" $collectorResources | nindent 10 }}
           {{- include "cloudzero-agent.generateContainerSecurityContext" (mergeOverwrite
               (.Values.defaults.securityContext | default (dict))
               (.Values.aggregator.collector.securityContext | default (dict))

helm/tests/aggregator_resources_fallback_test.yaml

@@ -87,3 +87,54 @@ tests:
       - equal:
           path: spec.template.spec.containers[0].resources.limits.cpu
           value: "4000m"
+
+  - it: should render ephemeral-storage requests and limits
+    set:
+      components.aggregator.collector.resources:
+        requests:
+          ephemeral-storage: "1Gi"
+        limits:
+          ephemeral-storage: "2Gi"
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.ephemeral-storage
+          value: "1Gi"
+      - equal:
+          path: spec.template.spec.containers[0].resources.limits.ephemeral-storage
+          value: "2Gi"
+
+  - it: should request the emptyDir sizeLimit as collector ephemeral-storage
+    set:
+      aggregator.database.emptyDir.sizeLimit: "5Gi"
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.ephemeral-storage
+          value: "5Gi"
+      - notExists:
+          path: spec.template.spec.containers[0].resources.limits.ephemeral-storage
+      - notExists:
+          path: spec.template.spec.containers[1].resources.requests.ephemeral-storage
+
+  - it: should prefer an explicit collector ephemeral-storage request over the sizeLimit
+    set:
+      aggregator.database.emptyDir.sizeLimit: "5Gi"
+      components.aggregator.collector.resources:
+        requests:
+          ephemeral-storage: "1Gi"
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.ephemeral-storage
+          value: "1Gi"
+
+  - it: should not request ephemeral-storage when no sizeLimit is set
+    asserts:
+      - notExists:
+          path: spec.template.spec.containers[0].resources.requests.ephemeral-storage
+
+  - it: should not request ephemeral-storage when the emptyDir is disabled
+    set:
+      aggregator.database.emptyDir.enabled: false
+      aggregator.database.emptyDir.sizeLimit: "5Gi"
+    asserts:
+      - notExists:
+          path: spec.template.spec.containers[0].resources.requests.ephemeral-storage

helm/values.yaml

@@ -1749,6 +1749,12 @@ aggregator:
       # Whether to enable the emptyDir volume for the aggregator.
       enabled: true
       # Size limit for the emptyDir volume. If not set, no limit is applied.
+      #
+      # When set, this is also used as the collector container's
+      # ephemeral-storage request, so the pod is only scheduled onto a node
+      # with enough allocatable ephemeral storage. Set
+      # components.aggregator.collector.resources.requests.ephemeral-storage
+      # to override it.
       sizeLimit: ""
   # Configuration for the collector component of the aggregator.
   collector: