netdata/netdata

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

package consul

import (
    _ "embed"
    "errors"
    "net/http"
    "sync"
    "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"

    "github.com/blang/semver/v4"
)

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

func init() {
    module.Register("consul", module.Creator{
        JobConfigSchema: configSchema,
        Defaults: module.Defaults{
            UpdateEvery: 1,
        },
        Create: func() module.Module { return New() },
        Config: func() any { return &Config{} },
    })
}

func New() *Consul {
    return &Consul{
        Config: Config{
            HTTP: web.HTTP{
                Request: web.Request{
                    URL: "http://127.0.0.1:8500",
                },
                Client: web.Client{
                    Timeout: web.Duration(time.Second),
                },
            },
        },
        charts:                       &module.Charts{},
        addGlobalChartsOnce:          &sync.Once{},
        addServerAutopilotChartsOnce: &sync.Once{},
        checks:                       make(map[string]bool),
    }
}

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

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

    charts                       *module.Charts
    addGlobalChartsOnce          *sync.Once
    addServerAutopilotChartsOnce *sync.Once

    httpClient *http.Client
    prom       prometheus.Prometheus

    cfg               *consulConfig
    version           *semver.Version
    hasLeaderCharts   bool
    hasFollowerCharts bool
    checks            map[string]bool
}

func (c *Consul) Configuration() any {
    return c.Config
}

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

    httpClient, err := c.initHTTPClient()
    if err != nil {
        c.Errorf("init HTTP client: %v", err)
        return err
    }
    c.httpClient = httpClient

    prom, err := c.initPrometheusClient(httpClient)
    if err != nil {
        c.Errorf("init Prometheus client: %v", err)
        return err
    }
    c.prom = prom

    return nil
}

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

    }
    return nil
}

func (c *Consul) Charts() *module.Charts {
    return c.charts
}

func (c *Consul) Collect() map[string]int64 {
    mx, err := c.collect()
    if err != nil {
        c.Error(err)
    }

    if len(mx) == 0 {
        return nil
    }
    return mx
}

func (c *Consul) Cleanup() {
    if c.httpClient != nil {
        c.httpClient.CloseIdleConnections()
    }
}