mirror of
https://github.com/puppetmaster/typhoon.git
synced 2025-02-20 17:51:26 +01:00
51 lines
2.1 KiB
Markdown
51 lines
2.1 KiB
Markdown
# Prometheus
|
|
|
|
Prometheus collects metrics (e.g. `node_memory_usage_bytes`) from *targets* by scraping their HTTP metrics endpoints. Targets are organized into *jobs*, defined in the Prometheus config. Targets may expose counter, gauge, histogram, or summary metrics.
|
|
|
|
Here's a simple config from the Prometheus [tutorial](https://prometheus.io/docs/introduction/getting_started/).
|
|
|
|
```
|
|
global:
|
|
scrape_interval: 15s
|
|
scrape_configs:
|
|
- job_name: 'prometheus'
|
|
scrape_interval: 5s
|
|
static_configs:
|
|
- targets: ['localhost:9090']
|
|
```
|
|
|
|
On Kubernetes clusters, Prometheus is run as a Deployment, configured with a ConfigMap, and accessed via a Service or Ingress.
|
|
|
|
```
|
|
kubectl apply -f addons/prometheus -R
|
|
```
|
|
|
|
The ConfigMap configures Prometheus to discover apiservers, kubelets, cAdvisor, services, endpoints, and exporters. By default, data is kept in an `emptyDir` so it is persisted until the pod is rescheduled.
|
|
|
|
### Exporters
|
|
|
|
Exporters expose metrics for 3rd-party systems that don't natively expose Prometheus metrics.
|
|
|
|
* [node_exporter](https://github.com/prometheus/node_exporter) - DaemonSet that exposes a machine's hardware and OS metrics
|
|
* [kube-state-metrics](https://github.com/kubernetes/kube-state-metrics) - Deployment that exposes Kubernetes object metrics
|
|
* [blackbox_exporter](https://github.com/prometheus/blackbox_exporter) - Scrapes HTTP, HTTPS, DNS, TCP, or ICMP endpoints and exposes availability as metrics
|
|
|
|
### Queries and Alerts
|
|
|
|
Prometheus provides a basic UI for querying metrics and viewing alerts. Use `kubectl` to authenticate to the apiserver and create a local port-forward to the Prometheus pod.
|
|
|
|
```
|
|
kubectl get pods -n monitoring
|
|
kubectl port-forward prometheus-POD-ID 9090 -n monitoring
|
|
```
|
|
|
|
Visit [127.0.0.1:9090](http://127.0.0.1:9090) to query [expressions](http://127.0.0.1:9090/graph), view [targets](http://127.0.0.1:9090/targets), or check [alerts](http://127.0.0.1:9090/alerts).
|
|
|
|
|
|
<br/>
|
|
|
|
<br/>
|
|
|
|
|
|
Use [Grafana](/addons/grafana.md) to view or build dashboards that use Prometheus as the datasource.
|