[prometheus-node-exporter] Parameterise host root FS mount propagation

charts/prometheus-node-exporter/Chart.yaml

@@ -2,16 +2,16 @@ apiVersion: v2
 name: prometheus-node-exporter
 description: A Helm chart for prometheus node-exporter
 keywords:
-- node-exporter
-- prometheus
-- exporter
+  - node-exporter
+  - prometheus
+  - exporter
 type: application
-version: 2.5.0
+version: 3.0.0
 appVersion: 1.3.1
 home: https://github.com/prometheus/node_exporter/
 sources:
-- https://github.com/prometheus/node_exporter/
+  - https://github.com/prometheus/node_exporter/
 maintainers:
-- email: [email protected]
-  name: gianrubio
-- name: bismarck
+  - email: [email protected]
+    name: gianrubio
+  - name: bismarck

charts/prometheus-node-exporter/README.md

@@ -41,6 +41,22 @@ helm upgrade [RELEASE_NAME] [CHART] --install
 
 _See [helm upgrade](https://helm.sh/docs/helm/helm_upgrade/) for command documentation._
 
+### From 2.x to 3.x
+
+Change the following:
+
+```yaml
+hostRootFsMount: true
+```
+
+to:
+
+```yaml
+hostRootFsMount:
+  enabled: true
+  mountPropagation: HostToContainer
+```
+
 ## Configuring
 
 See [Customizing the Chart Before Installing](https://helm.sh/docs/intro/using_helm/#customizing-the-chart-before-installing). To see all configurable options with detailed comments, visit the chart's [values.yaml](./values.yaml), or run these configuration commands:

charts/prometheus-node-exporter/templates/daemonset.yaml

@@ -41,7 +41,7 @@ spec:
           args:
             - --path.procfs=/host/proc
             - --path.sysfs=/host/sys
-            {{- if .Values.hostRootFsMount }}
+            {{- if .Values.hostRootFsMount.enabled }}
             - --path.rootfs=/host/root
             {{- end }}
             - --web.listen-address=$(HOST_IP):{{ .Values.service.port }}
@@ -82,10 +82,12 @@ spec:
             - name: sys
               mountPath: /host/sys
               readOnly: true
-            {{- if .Values.hostRootFsMount }}
+            {{- if .Values.hostRootFsMount.enabled }}
             - name: root
               mountPath: /host/root
-              mountPropagation: HostToContainer
+              {{- with .Values.hostRootFsMount.mountPropagation }}
+              mountPropagation: {{ . }}
+              {{- end }}
               readOnly: true
             {{- end }}
             {{- if .Values.extraHostVolumeMounts }}
@@ -153,7 +155,7 @@ spec:
         - name: sys
           hostPath:
             path: /sys
-        {{- if .Values.hostRootFsMount }}
+        {{- if .Values.hostRootFsMount.enabled }}
         - name: root
           hostPath:
             path: /

charts/prometheus-node-exporter/values.yaml

@@ -100,9 +100,15 @@ hostNetwork: true
 # Share the host process ID namespace
 hostPID: true
 
-## If true, node-exporter pods mounts host / at /host/root
-##
-hostRootFsMount: true
+# Mount the node's root file system (/) at /host/root in the container
+hostRootFsMount:
+  enabled: true
+  # Defines how new mounts in existing mounts on the node or in the container
+  # are propagated to the container or node, respectively. Possible values are
+  # None, HostToContainer, and Bidirectional. If this field is omitted, then
+  # None is used. More information on:
+  # https://kubernetes.io/docs/concepts/storage/volumes/#mount-propagation
+  mountPropagation: HostToContainer
 
 ## Assign a group of affinity scheduling rules
 ##