Merge pull request #230032 from DhruvSehgal/dhruvsehgal/update-os-provider-documentation

update OS provider documentation for setting up cron job to start nod…

Author: v-regandowner

articles/sap/monitor/provider-linux.md

@@ -5,7 +5,7 @@ author: MightySuz
 ms.service: sap-on-azure
 ms.subservice: sap-monitor
 ms.topic: how-to
-ms.date: 01/05/2023
+ms.date: 03/09/2023
 ms.author: sujaj
 #Customer intent: As a developer, I want to configure a Linux provider so that I can use Azure Monitor for SAP solutions for monitoring.
 ---
@@ -21,7 +21,7 @@ This content applies to both versions of the service, *Azure Monitor for SAP sol
 
 - An Azure subscription.
 - An existing Azure Monitor for SAP solutions resource. To create an Azure Monitor for SAP solutions resource, see the [quickstart for the Azure portal](quickstart-portal.md) or the [quickstart for PowerShell](quickstart-powershell.md).
-- Install the [node exporter version 1.3.0](https://prometheus.io/download/#node_exporter) in each SAP host that you want to monitor, either BareMetal or Azure virtual machine (Azure VM). For more information, see [the node exporter GitHub repository](https://github.com/prometheus/node_exporter).
+- Install the [node exporter latest version](https://prometheus.io/download/#node_exporter) in each SAP host that you want to monitor, either BareMetal or Azure virtual machine (Azure VM). For more information, see [the node exporter GitHub repository](https://github.com/prometheus/node_exporter).
 
 To install the node exporter on Linux:
 
@@ -35,6 +35,26 @@ To install the node exporter on Linux:
 
 1. The node exporter now starts collecting data. You can export the data at `http://IP:9100/metrics`.
 
+## Script to setup Node Exporter
+
+```shell
+# To get the latest node exporter version from: https://prometheus.io/download/#node_exporter
+wget https://github.com/prometheus/node_exporter/releases/download/v*/node_exporter-*.*-amd64.tar.gz
+tar xvfz node_exporter-*.*-amd64.tar.gz
+if [[ "$(grep '^ID=' /etc/*-release)" == *"rhel"* ]]; then
+    echo "Open firewall port 9100 on the Linux host"
+    sudo apt install firewalld -y
+    systemctl start firewalld
+    firewall-cmd --zone=public --permanent --add-port 9100/tcp
+else
+    sudo ufw allow 9100/tcp
+    sudo ufw reload
+fi
+
+cd node_exporter-*.*-amd64
+nohup ./node_expoprter --web.listen-address=":9100" &
+```
+
 ## Prerequisites to enable secure communication
 
 To [enable TLS 1.2 or higher](enable-tls-azure-monitor-sap-solutions.md), follow the steps [mentioned here](https://prometheus.io/docs/guides/tls-encryption/)
@@ -74,8 +94,29 @@ When the provider settings validation operation fails with the code ‘Prometheu
 1. Try to restart the node exporter agent:
     1. Go to the folder where you installed the node exporter (the file name resembles `node_exporter-*.*-amd64`).
     1. Run `./node_exporter`.
+    1. Adding nohup and & to aboe command decouples the node_exporter from linux machine commandline. If not included node_exporter would stop when the commandline is closed.
 1. Verify that the Prometheus endpoint is reachable from the subnet that you provided while creating the Azure Monitor for SAP solutions resource.
 
+## Suggestions
+
+### Enabling Node Exporter
+
+1. Run `nohup ./node_exporter &` command to enable node_exporter.
+1. Adding nohup and & to aboe command decouples the node_exporter from linux machine commandline. If not included node_exporter would stop when the commandline is closed.
+
+### Setting up cron job to start Node exporter on VM restart
+
+1. If the target virtual machine is restarted/stopped, node exporter is also stopped, and needs to be manually started again to continue monitoring.
+1. Run `sudo crontab -e` command to open cron file.
+1. Add the command `@reboot cd /path/to/node/exporter && nohup ./node_exporter &` at the end of cron file. This will start node exporter on VM reboot.
+
+```shell
+sudo crontab -l > crontab_new
+echo "@reboot cd /path/to/node/exporter && nohup ./node_exporter &" >> crontab_new
+sudo crontab crontab_new
+sudo rm crontab_new
+```
+
 ## Next steps
 
 > [!div class="nextstepaction"]