Prometheus NodeExporter, k8s integration

You need a Kubernetes cluster with Prometheus server installed and running.

Contents

What is Prometheus NodeExporter

Prometheus Node Exporter is an open-source tool designed to expose system-level metrics for servers, making them available to Prometheus for monitoring. It provides detailed insights into the hardware and operating system, including metrics like CPU usage, memory usage, disk I/O, and network statistics.

Prometheus NodeExporter, Configuration

Installation

For convenience, we used an account with root privileges. In environments where security is required, you can set it to user privileges.

wget https://github.com/prometheus/node_exporter/releases/download/v1.8.1/node_exporter-1.8.1.linux-amd64.tar.gz

tar -xvf node_exporter-1.8.1.linux-amd64.tar.gz

mv node_exporter-1.8.1.linux-amd64 /usr/local/bin/node_exporter

vi /etc/systemd/system/node_exporter.service

Configure the contents of the daemon executable appropriately.
(CPU and Mempry limits have been set. Because it is a free OracleCloud VM, the resource size is small…)

[Unit]
Description=Node Exporter
Wants=network-online.target
After=network-online.target

[Service]
User=root
Group=root
Type=simple
ExecStart=/usr/local/bin/node_exporter/node_exporter
CPUQuota=20%
MemoryLimit=100M

[Install]
WantedBy=multi-user.target

systemctl daemon-reload
systemctl enable node_exporter.service
systemctl start node_exporter.service

Check installation

systemctl status node_exporter.service

Check open Port

ss -nltp

Additional OracleCloud vm settings (optional)

If iptable issues occur when configuring Oracle Cloud’s vm operating system as Ubuntu 22.04, you need to add the values below and set additional SG and ACL policies.

Allow port 9100 in all IP bands (optional)

iptables -I INPUT 5 -i ens3 -p tcp --dport 9100 -m state --state NEW,ESTABLISHED -j ACCEPT

Allow port 9100 only for specific IP bands (optional)
Modify and apply 0.0.0.0/0 in the content below.

iptables -I INPUT 5 -s 0.0.0.0/0 -p tcp --dport 9100 -m state --state NEW,ESTABLISHED -j ACCEPT

If you need to delete settings, refer to the information below.

iptables -L --line-numbers

iptables -D INPUT 5 # 등록되어있는 정책 번호

Metric collection and inspection

Test by replacing localhost with IP information.

curl http://localhost:9100/metrics

Prometheus Server, Configuration

Settings for retrieving NodeExporter information from a Prometheus server configured on Kubernetes.
Add it to the configmap information in a similar way as below.

# 0.0.0.0:9100 부분을 본인이 사용하는 노드 주소값으로 변경.
scrape_configs:
- job_name: hm-vm # vm연동 정보.
  static_configs:
  - targets: ['0.0.0.0:9100']
    labels:
      node: 'your node_name'