firehol/netdata

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

package netdataapi

import (
    "bytes"
    "fmt"
    "io"
    "strconv"
)

type (
    // API implements Netdata external plugins API.
    // https://learn.netdata.cloud/docs/agent/collectors/plugins.d#the-output-of-the-plugin
    API struct {
        io.Writer
    }
)

const quotes = "' '"

var (
    end          = []byte("END\n\n")
    clabelCommit = []byte("CLABEL_COMMIT\n")
    newLine      = []byte("\n")
)

func New(w io.Writer) *API { return &API{w} }

// CHART  creates or update a chart.
func (a *API) CHART(
    typeID string,
    ID string,
    name string,
    title string,
    units string,
    family string,
    context string,
    chartType string,
    priority int,
    updateEvery int,
    options string,
    plugin string,
    module string) error {
    _, err := a.Write([]byte("CHART " + "'" +
        typeID + "." + ID + quotes +
        name + quotes +
        title + quotes +
        units + quotes +
        family + quotes +
        context + quotes +
        chartType + quotes +
        strconv.Itoa(priority) + quotes +
        strconv.Itoa(updateEvery) + quotes +
        options + quotes +
        plugin + quotes +
        module + "'\n"))
    return err
}

// DIMENSION adds or update a dimension to the chart just created.
func (a *API) DIMENSION(
    ID string,
    name string,
    algorithm string,
    multiplier int,
    divisor int,
    options string) error {
    _, err := a.Write([]byte("DIMENSION '" +
        ID + quotes +
        name + quotes +
        algorithm + quotes +
        strconv.Itoa(multiplier) + quotes +
        strconv.Itoa(divisor) + quotes +
        options + "'\n"))
    return err
}

// CLABEL adds or update a label to the chart.
func (a *API) CLABEL(key, value string, source int) error {
    _, err := a.Write([]byte("CLABEL '" +
        key + quotes +
        value + quotes +
        strconv.Itoa(source) + "'\n"))
    return err
}

// CLABELCOMMIT adds labels to the chart. Should be called after one or more CLABEL.
func (a *API) CLABELCOMMIT() error {
    _, err := a.Write(clabelCommit)
    return err
}

// BEGIN initializes data collection for a chart.
func (a *API) BEGIN(typeID string, ID string, msSince int) (err error) {
    if msSince > 0 {
        _, err = a.Write([]byte("BEGIN " + "'" + typeID + "." + ID + "' " + strconv.Itoa(msSince) + "\n"))
    } else {
        _, err = a.Write([]byte("BEGIN " + "'" + typeID + "." + ID + "'\n"))
    }
    return err
}

// SET sets the value of a dimension for the initialized chart.
func (a *API) SET(ID string, value int64) error {
    _, err := a.Write([]byte("SET '" + ID + "' = " + strconv.FormatInt(value, 10) + "\n"))
    return err
}

// SETEMPTY sets the empty value of a dimension for the initialized chart.
func (a *API) SETEMPTY(ID string) error {
    _, err := a.Write([]byte("SET '" + ID + "' = \n"))
    return err
}

// VARIABLE sets the value of a CHART scope variable for the initialized chart.
func (a *API) VARIABLE(ID string, value int64) error {
    _, err := a.Write([]byte("VARIABLE CHART '" + ID + "' = " + strconv.FormatInt(value, 10) + "\n"))
    return err
}

// END completes data collection for the initialized chart.
func (a *API) END() error {
    _, err := a.Write(end)
    return err
}

// DISABLE disables this plugin. This will prevent Netdata from restarting the plugin.
func (a *API) DISABLE() error {
    _, err := a.Write([]byte("DISABLE\n"))
    return err
}

// EMPTYLINE writes an empty line.
func (a *API) EMPTYLINE() error {
    _, err := a.Write(newLine)
    return err
}

func (a *API) HOSTINFO(guid, hostname string, labels map[string]string) error {
    if err := a.HOSTDEFINE(guid, hostname); err != nil {
        return err
    }
    for k, v := range labels {
        if err := a.HOSTLABEL(k, v); err != nil {
            return err
        }
    }
    return a.HOSTDEFINEEND()
}

func (a *API) HOSTDEFINE(guid, hostname string) error {
    _, err := fmt.Fprintf(a, "HOST_DEFINE '%s' '%s'\n", guid, hostname)
    return err
}

func (a *API) HOSTLABEL(name, value string) error {
    _, err := fmt.Fprintf(a, "HOST_LABEL '%s' '%s'\n", name, value)
    return err
}

func (a *API) HOSTDEFINEEND() error {
    _, err := fmt.Fprintf(a, "HOST_DEFINE_END\n\n")
    return err
}

func (a *API) HOST(guid string) error {
    _, err := a.Write([]byte("HOST " + "'" +
        guid + "'\n\n"))
    return err
}

func (a *API) FUNCRESULT(uid, contentType, payload, code, expireTimestamp string) {
    var buf bytes.Buffer

    buf.WriteString("FUNCTION_RESULT_BEGIN " +
        uid + " " +
        code + " " +
        contentType + " " +
        expireTimestamp + "\n",
    )

    if payload != "" {
        buf.WriteString(payload + "\n")
    }

    buf.WriteString("FUNCTION_RESULT_END\n\n")

    _, _ = buf.WriteTo(a)
}

func (a *API) CONFIGCREATE(id, status, configType, path, sourceType, source, supportedCommands string) {
    // https://learn.netdata.cloud/docs/contributing/external-plugins/#config

    _, _ = a.Write([]byte("CONFIG " +
        id + " " +
        "create" + " " +
        status + " " +
        configType + " " +
        path + " " +
        sourceType + " '" +
        source + "' '" +
        supportedCommands + "' 0x0000 0x0000\n\n",
    ))
}

func (a *API) CONFIGDELETE(id string) {
    _, _ = a.Write([]byte("CONFIG " + id + " delete\n\n"))
}

func (a *API) CONFIGSTATUS(id, status string) {
    _, _ = a.Write([]byte("CONFIG " + id + " status " + status + "\n\n"))
}