# Kubernetes Input Plugin

The Kubernetes plugin talks to the Kubelet API and gathers metrics about the
running pods and containers for a single host. It is assumed that this plugin
is running as part of a `daemonset` within a kubernetes installation. This
means that telegraf is running on every node within the cluster. Therefore, you
should configure this plugin to talk to its locally running kubelet.

To find the ip address of the host you are running on you can issue a command
like the following:

```sh
curl -s $API_URL/api/v1/namespaces/$POD_NAMESPACE/pods/$HOSTNAME --header "Authorization: Bearer $TOKEN" --insecure | jq -r '.status.hostIP'
```

In this case we used the downward API to pass in the `$POD_NAMESPACE` and
`$HOSTNAME` is the hostname of the pod which is set by the kubernetes API.

Kubernetes is a fast moving project, with a new minor release every 3 months. As
such, we will aim to maintain support only for versions that are supported by
the major cloud providers; this is roughly 4 release / 2 years.

**This plugin supports Kubernetes 1.11 and later.**

## Series Cardinality Warning

This plugin may produce a high number of series which, when not controlled
for, will cause high load on your database. Use the following techniques to
avoid cardinality issues:

- Use [metric filtering][] options to exclude unneeded measurements and tags.
- Write to a database with an appropriate [retention policy][].
- Consider using the [Time Series Index][tsi].
- Monitor your databases [series cardinality][].
- Consult the [InfluxDB documentation][influx-docs] for the most up-to-date techniques.

## Configuration

```toml @sample.conf
# Read metrics from the kubernetes kubelet api
[[inputs.kubernetes]]
  ## URL for the kubelet
  url = "http://127.0.0.1:10255"

  ## Use bearer token for authorization. ('bearer_token' takes priority)
  ## If both of these are empty, we'll use the default serviceaccount:
  ## at: /run/secrets/kubernetes.io/serviceaccount/token
  # bearer_token = "/path/to/bearer/token"
  ## OR
  # bearer_token_string = "abc_123"

  ## Pod labels to be added as tags.  An empty array for both include and
  ## exclude will include all labels.
  # label_include = []
  # label_exclude = ["*"]

  ## Set response_timeout (default 5 seconds)
  # response_timeout = "5s"

  ## Optional TLS Config
  # tls_ca = /path/to/cafile
  # tls_cert = /path/to/certfile
  # tls_key = /path/to/keyfile
  ## Use TLS but skip chain & host verification
  # insecure_skip_verify = false
```

## DaemonSet

For recommendations on running Telegraf as a DaemonSet see [Monitoring
Kubernetes Architecture][k8s-telegraf] or view the Helm charts:

- [Telegraf][]
- [InfluxDB][]
- [Chronograf][]
- [Kapacitor][]

## Metrics

- kubernetes_node
  - tags:
    - node_name
  - fields:
    - cpu_usage_nanocores
    - cpu_usage_core_nanoseconds
    - memory_available_bytes
    - memory_usage_bytes
    - memory_working_set_bytes
    - memory_rss_bytes
    - memory_page_faults
    - memory_major_page_faults
    - network_rx_bytes
    - network_rx_errors
    - network_tx_bytes
    - network_tx_errors
    - fs_available_bytes
    - fs_capacity_bytes
    - fs_used_bytes
    - runtime_image_fs_available_bytes
    - runtime_image_fs_capacity_bytes
    - runtime_image_fs_used_bytes

- kubernetes_pod_container
  - tags:
    - container_name
    - namespace
    - node_name
    - pod_name
  - fields:
    - cpu_usage_nanocores
    - cpu_usage_core_nanoseconds
    - memory_usage_bytes
    - memory_working_set_bytes
    - memory_rss_bytes
    - memory_page_faults
    - memory_major_page_faults
    - rootfs_available_bytes
    - rootfs_capacity_bytes
    - rootfs_used_bytes
    - logsfs_available_bytes
    - logsfs_capacity_bytes
    - logsfs_used_bytes

- kubernetes_pod_volume
  - tags:
    - volume_name
    - namespace
    - node_name
    - pod_name
  - fields:
    - available_bytes
    - capacity_bytes
    - used_bytes

- kubernetes_pod_network
  - tags:
    - namespace
    - node_name
    - pod_name
  - fields:
    - rx_bytes
    - rx_errors
    - tx_bytes
    - tx_errors

## Example Output

```shell
kubernetes_node
kubernetes_pod_container,container_name=deis-controller,namespace=deis,node_name=ip-10-0-0-0.ec2.internal,pod_name=deis-controller-3058870187-xazsr cpu_usage_core_nanoseconds=2432835i,cpu_usage_nanocores=0i,logsfs_available_bytes=121128271872i,logsfs_capacity_bytes=153567944704i,logsfs_used_bytes=20787200i,memory_major_page_faults=0i,memory_page_faults=175i,memory_rss_bytes=0i,memory_usage_bytes=0i,memory_working_set_bytes=0i,rootfs_available_bytes=121128271872i,rootfs_capacity_bytes=153567944704i,rootfs_used_bytes=1110016i 1476477530000000000
kubernetes_pod_network,namespace=deis,node_name=ip-10-0-0-0.ec2.internal,pod_name=deis-controller-3058870187-xazsr rx_bytes=120671099i,rx_errors=0i,tx_bytes=102451983i,tx_errors=0i 1476477530000000000
kubernetes_pod_volume,volume_name=default-token-f7wts,namespace=default,node_name=ip-172-17-0-1.internal,pod_name=storage-7 available_bytes=8415240192i,capacity_bytes=8415252480i,used_bytes=12288i 1546910783000000000
kubernetes_system_container
```

[metric filtering]: https://github.com/influxdata/telegraf/blob/master/docs/CONFIGURATION.md#metric-filtering
[retention policy]: https://docs.influxdata.com/influxdb/latest/guides/downsampling_and_retention/
[tsi]: https://docs.influxdata.com/influxdb/latest/concepts/time-series-index/
[series cardinality]: https://docs.influxdata.com/influxdb/latest/query_language/spec/#show-cardinality
[influx-docs]: https://docs.influxdata.com/influxdb/latest/
[k8s-telegraf]: https://www.influxdata.com/blog/monitoring-kubernetes-architecture/
[telegraf]: https://github.com/helm/charts/tree/master/stable/telegraf
[influxdb]: https://github.com/helm/charts/tree/master/stable/influxdb
[chronograf]: https://github.com/helm/charts/tree/master/stable/chronograf
[kapacitor]: https://github.com/helm/charts/tree/master/stable/kapacitor
