Scrape via Prometheus annotation

README.md

@@ -1,68 +1,46 @@
 # monitor-pv
+
 custom stats collector for OpenEBS persistent volumes (jiva, localpv)
 
-### Pre-requisite
+## Pre-requisite
+
 - openebs (https://docs.openebs.io/)
 
-### How to use
-- Run `kubectl apply -f node-exporter-pv-metrics.yaml`
+## How to use
+
+- Run `kubectl apply -f monitor-pv.yaml`
 - Verify if the pods are up and running.
-<pre>
+
+```console
 $ kubectl get pods -n openebs 
-NAME                                                              READY   STATUS    RESTARTS   AGE
-cspc-operator-6c4cc7c64d-698ps                                    1/1     Running   0          6d23h
-cvc-operator-77d749c559-9phff                                     1/1     Running   0          6d23h
-maya-apiserver-5fb947d74d-r9skp                                   1/1     Running   0          6d23h
-<b>monitor-pv-bvzgv                                                  2/2     Running   0          8s
-monitor-pv-nk76b                                                  2/2     Running   0          11s
-monitor-pv-wnvp5                                                  2/2     Running   0          8s</b>
-openebs-admission-server-6c4b4998f8-zcg9n                         1/1     Running   0          6d23h
-openebs-localpv-provisioner-5b744fc789-5wr8d                      1/1     Running   0          6d23h
-openebs-ndm-g474w                                                 1/1     Running   0          6d23h
-openebs-ndm-k2nnp                                                 1/1     Running   0          6d23h
-openebs-ndm-operator-b58c79cc5-z8zw6                              1/1     Running   1          6d23h
-openebs-ndm-rwzrb                                                 1/1     Running   0          6d23h
-openebs-provisioner-54d45b55db-rt5rv                              1/1     Running   0          6d23h
-openebs-snapshot-operator-6d4f5d7688-6g7zw                        2/2     Running   0          6d23h
-pvc-dd03f0ae-731c-4f78-bdbf-86485f32ab3d-ctrl-89b44f6cb-pbnmk     2/2     Running   0          40h
-pvc-dd03f0ae-731c-4f78-bdbf-86485f32ab3d-rep-1-857b65c68d-qrdx9   1/1     Running   0          40h
-pvc-dd03f0ae-731c-4f78-bdbf-86485f32ab3d-rep-2-58c4f54f7-m6n45    1/1     Running   0          40h
+NAME                READY   STATUS    RESTARTS   AGE
+...
+monitor-pv-bvzgv    2/2     Running   0          8s
+monitor-pv-nk76b    2/2     Running   0          11s
+monitor-pv-wnvp5    2/2     Running   0          8s
+...
+```
 
-</pre>
+## How it works
 
-### How it works
-The monitor PV daemonset pods consist of two containers i.e node-exporter and monitor-pv. The monitor-pv collects the PV size and PV utilization information & places it in a file on the shared mount. The node exporter uses its text-file collector to expose this data as metrics.
+The monitor PV daemonset pods consist of two containers i.e nginx and monitor-pv. The monitor-pv collects the PV size via `kubectl` and PV utilization information via `du`, and then places it in a text file on the shared emptydir mount. The nginx exposes this text file via HTTP so that Prometheus can scrape it as metrics.
 
 It exposes two metrics **pv_capacity_bytes** and **pv_utilization_bytes**.
 
-### Prometheus Configuration
-To scrape the metrics in prometheus add this configuration in prometheus configuration file:
-<pre>
-    - job_name: 'monitor-pv'
-      kubernetes_sd_configs:
-      - role: pod
-      relabel_configs:
-      - source_labels: [__meta_kubernetes_pod_label_app]
-        regex: monitor-pv
-        action: keep
-</pre>
+The pods are configured with Prometheus annotations so that a Prometheus instance installed in the cluster knows how to scrape:
+
+```yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  annotations:
+    prometheus.io/path: /scrape.txt
+    prometheus.io/port: "80"
+    prometheus.io/scrape: "true"
+```
 
-If you want to scrape only monitor-pv metrics and drop all other node-exporter metrics use the below configuration:
-<pre>
-    - job_name: 'monitor-pv'
-      kubernetes_sd_configs:
-      - role: pod
-      relabel_configs:
-      - source_labels: [__meta_kubernetes_pod_label_app]
-        regex: monitor-pv
-        action: keep
-      metric_relabel_configs:
-      - source_labels: [__name__]
-        regex: '(pv_capacity_bytes|pv_utilization_bytes)'
-        action: keep
-</pre>
+## Example
 
-### Example:
 ![monitor-pv-1](https://user-images.githubusercontent.com/29499601/81772797-67141a80-9504-11ea-901b-fe165900d60c.png)
 
 ![monitor-pv-2](https://user-images.githubusercontent.com/29499601/81772848-8a3eca00-9504-11ea-8d0b-e7a572a06aef.png)

monitor-pv.yaml

@@ -0,0 +1,114 @@
+# monitor-pv will launch as a daemonset.
+# Make sure to update namespace on ClusterRoleBinding below.
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: openebs-monitor-pv
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: openebs-monitor-pv
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - persistentvolumes
+  verbs:
+  - list
+  - get
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: openebs-monitor-pv
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: openebs-monitor-pv
+subjects:
+- kind: ServiceAccount
+  name: openebs-monitor-pv
+  namespace: openebs # NOTE: Update namespace here if deploying to a different namespace
+---
+apiVersion: apps/v1
+kind: DaemonSet
+metadata:
+  name: openebs-monitor-pv
+spec:
+  selector:
+    matchLabels:
+      app: openebs-monitor-pv
+  template:
+    metadata:
+      labels:
+        app: openebs-monitor-pv
+      annotations:
+        prometheus.io/path: /scrape.txt
+        prometheus.io/port: "80"
+        prometheus.io/scrape: "true"
+      name: openebs-monitor-pv
+    spec:
+      serviceAccount: openebs-monitor-pv
+      containers:
+        - name: monitor-pv
+          image: openebs/monitor-pv:ci
+          imagePullPolicy: Always
+          env:
+            - name: TEXTFILE_PATH
+              value: /shared_vol/scrape.txt
+            - name: COLLECT_INTERVAL 
+              value: "10"
+            - name: PROVISIONER_WHITELIST
+              value: "openebs.io/provisioner-iscsi,openebs.io/local"
+          command:
+            - /bin/bash
+          args:
+            - -c
+            - ./textfile_collector.sh
+          resources:
+            requests:
+              memory: "40M"
+              cpu: "200m"
+            limits:
+              memory: "100M"
+              cpu: "200m"
+          volumeMounts:
+            - mountPath: /host/proc
+              name: proc
+            - mountPath: /host/sys
+              name: sys
+            - mountPath: /host/root
+              mountPropagation: HostToContainer
+              name: root
+              readOnly: true
+            - mountPath: /shared_vol
+              name: shared
+        - image: nginx:alpine
+          name: nginx
+          ports:
+            - containerPort: 80
+              name: scrape
+          resources:
+            requests:
+              memory: "60M"
+              cpu: "1m"
+            limits:
+              memory: "100M"
+              cpu: "10m"
+      ## Uncomment this to also run on control-plane nodes
+      #tolerations:
+      #  - effect: NoSchedule
+      #    operator: Exists
+      volumes:
+        - name: proc
+          hostPath:
+            path: /proc
+        - name: sys
+          hostPath:
+            path: /sys
+        - name: root
+          hostPath:
+            path: /
+        - name: shared
+          emptyDir: {}