📌 Introduction to Monitoring with Prometheus & Grafana

Prometheus is an open-source monitoring tool designed for metrics collection and alerting, while Grafana is used for visualizing those metrics.

🔹 1. Installing Prometheus

1.1 Download and Install Prometheus

wget https://github.com/prometheus/prometheus/releases/latest/download/prometheus-linux-amd64.tar.gz
tar -xvf prometheus-linux-amd64.tar.gz
cd prometheus-linux-amd64

1.2 Configure Prometheus

Modify prometheus.yml to scrape metrics from a target (e.g., a Node Exporter).

📌 prometheus.yml

global:
  scrape_interval: 15s

scrape_configs:
  - job_name: "node_exporter"
    static_configs:
      - targets: ["localhost:9100"]

1.3 Start Prometheus

./prometheus --config.file=prometheus.yml

✅ Prometheus is now running on http://localhost:9090.

🔹 2. Installing Node Exporter (For System Metrics)

Node Exporter allows Prometheus to collect CPU, Memory, Disk, and Network usage.

wget https://github.com/prometheus/node_exporter/releases/latest/download/node_exporter-linux-amd64.tar.gz
tar -xvf node_exporter-linux-amd64.tar.gz
cd node_exporter-linux-amd64
./node_exporter

✅ Metrics are now available at http://localhost:9100/metrics.

🔹 3. Installing Grafana

3.1 Install Grafana on Ubuntu

sudo apt-get install -y software-properties-common
sudo add-apt-repository "deb https://packages.grafana.com/oss/deb stable main"
sudo apt-get update
sudo apt-get install -y grafana

3.2 Start Grafana

sudo systemctl start grafana-server
sudo systemctl enable grafana-server

✅ Grafana is now running on http://localhost:3000 (Default login: admin/admin).

🔹 4. Connecting Prometheus to Grafana

1️⃣ Go to Grafana → Settings → Data Sources → Add Data Source
2️⃣ Select Prometheus
3️⃣ Set URL to http://localhost:9090
4️⃣ Click Save & Test

✅ Now, Prometheus is connected to Grafana.

🔹 5. Creating Dashboards in Grafana

1️⃣ Go to Grafana → Create Dashboard → Add New Panel
2️⃣ Choose a Prometheus Query (e.g., node_cpu_seconds_total)
3️⃣ Select Graph Visualization
4️⃣ Click Save Dashboard

✅ Now, Grafana visualizes real-time system metrics.

🔹 6. Setting Up Alerts in Grafana

1️⃣ Go to Alerting → Create New Alert Rule
2️⃣ Select a Prometheus Query
3️⃣ Set Threshold Conditions (e.g., CPU usage > 80%)
4️⃣ Configure Notification Channel (Email, Slack, etc.)

✅ Now, alerts trigger when thresholds are exceeded.

📌 Conclusion

Prometheus collects real-time metrics.
Grafana visualizes and alerts on performance issues.
Together, they provide a powerful monitoring solution. 🚀