Bandwidth utilization by pod on Kubernetes

Question

Can someone tell me how I can get bandwidth usage per pod in Kubernetes from CLI? Ideally, I need something that will extract bandwidth usage for every pod.

Answer 1

Prometheus (and Thanos or Cortex, usually with some Grafana), is what you are looking for.

You have a Kubernetes (vanilla, OpenShift, ...), then kubelet/cadvisor should already be exposing some metrics, which you may scrape with Prometheus, and visualize in Grafana

See cadvisor docs in GitHub: https://github.com/google/cadvisor/blob/master/docs/storage/prometheus.md

Sample cadvisor scraping job in prometheus, discovering your nodes/targets integrating with Kubernetes API:

- job_name: cadvisor
  bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
  kubernetes_sd_configs:
  - role: node
  metrics_path: /metrics/cadvisor
  relabel_configs:
  - action: replace
    source_labels: [__meta_kubernetes_node_name]
    target_label: kubernetes_node_name
  scheme: https
  scrape_interval: 30s
  scrape_timeout: 10s
  tls_config:
    ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
    # if ca won't work, add this:
    # insecure_skip_verify: true

Grafana dashboards for Prometheus/Cadvisor: https://grafana.com/grafana/dashboards/?dataSource=prometheus&search=cadvisor

... And, you were asking about CLI ... I'm not sure I have an answer here. While scripting directly on top of cadvisor is obviously possible: it could take you some time to figure out what to query. Keeping in mind you would be exclusively working with instantenous values / as opposed to Prometheus, which has functions working with metrics over an interval of time.

If possible, I would still look into Prometheus. And once you have one: this you can query, getting bandwidth consumption per pod, container, ... Even in CLI / there's an API. Maybe writing a kubectl plugin, extending get pods/adm top pods

Answer 2

Kubecost is a good tool to get the overall usage metrics and associated costs, please take a look here https://blog.kubecost.com/blog/network-egress-traffic-costs/