netdata/netdata

// SPDX-License-Identifier: GPL-3.0-or-later

package k8s_kubelet

import (
    _ "embed"
    "errors"
    "time"

    "github.com/netdata/netdata/go/go.d.plugin/agent/module"
    "github.com/netdata/netdata/go/go.d.plugin/pkg/prometheus"
    "github.com/netdata/netdata/go/go.d.plugin/pkg/web"
)

//go:embed "config_schema.json"
var configSchema string

func init() {
    module.Register("k8s_kubelet", module.Creator{
        JobConfigSchema: configSchema,
        Defaults: module.Defaults{
            // NETDATA_CHART_PRIO_CGROUPS_CONTAINERS        40000
            Priority: 50000,
        },
        Create: func() module.Module { return New() },
        Config: func() any { return &Config{} },
    })
}

func New() *Kubelet {
    return &Kubelet{
        Config: Config{
            HTTP: web.HTTP{
                Request: web.Request{
                    URL:     "http://127.0.0.1:10255/metrics",
                    Headers: make(map[string]string),
                },
                Client: web.Client{
                    Timeout: web.Duration(time.Second),
                },
            },
            TokenPath: "/var/run/secrets/kubernetes.io/serviceaccount/token",
        },

        charts:             charts.Copy(),
        collectedVMPlugins: make(map[string]bool),
    }
}

type Config struct {
    UpdateEvery int `yaml:"update_every,omitempty" json:"update_every"`
    web.HTTP    `yaml:",inline" json:""`
    TokenPath   string `yaml:"token_path,omitempty" json:"token_path"`
}

type Kubelet struct {
    module.Base
    Config `yaml:",inline" json:""`

    charts *Charts

    prom prometheus.Prometheus

    collectedVMPlugins map[string]bool // volume_manager_total_volumes
}

func (k *Kubelet) Configuration() any {
    return k.Config
}

func (k *Kubelet) Init() error {
    if err := k.validateConfig(); err != nil {
        k.Errorf("config validation: %v", err)
        return err
    }

    prom, err := k.initPrometheusClient()
    if err != nil {
        k.Error(err)
        return err
    }
    k.prom = prom

    if tok := k.initAuthToken(); tok != "" {
        k.Request.Headers["Authorization"] = "Bearer " + tok
    }

    return nil
}

func (k *Kubelet) Check() error {
    mx, err := k.collect()
    if err != nil {
        k.Error(err)
        return err
    }
    if len(mx) == 0 {
        return errors.New("no metrics collected")
    }
    return nil
}

func (k *Kubelet) Charts() *Charts {
    return k.charts
}

func (k *Kubelet) Collect() map[string]int64 {
    mx, err := k.collect()

    if err != nil {
        k.Error(err)
        return nil
    }

    return mx
}

func (k *Kubelet) Cleanup() {
    if k.prom != nil && k.prom.HTTPClient() != nil {
        k.prom.HTTPClient().CloseIdleConnections()
    }
}