netdata/netdata

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

package consul

import (
    "fmt"
    "math"
    "strconv"
    "strings"

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

func (c *Consul) collectMetricsPrometheus(mx map[string]int64) error {
    mfs, err := c.prom.Scrape()
    if err != nil {
        return err
    }

    // Key Metrics (https://developer.hashicorp.com/consul/docs/agent/telemetry#key-metrics)

    // prometheus metrics are messy:
    // - if 'disable_hostname' is false (default):
    //   - consul_autopilot_failure_tolerance => consul_hostname_autopilot_failure_tolerance
    //   - both are exposed
    //   - only the one with the hostname has the correct value
    // - 1.14.3 (it probably has something to do with cloud management version):
    //   - runtime_sys_bytes => runtime_sys_bytes_sys_bytes; consul_autopilot_healthy => consul_autopilot_healthy_healthy
    //   - both are exposed
    //   - only the one with the double name has the correct value

    if c.isServer() {
        c.collectSummary(mx, mfs, "raft_thread_main_saturation")
        c.collectSummary(mx, mfs, "raft_thread_fsm_saturation")
        c.collectSummary(mx, mfs, "raft_boltdb_logsPerBatch")
        c.collectSummary(mx, mfs, "kvs_apply")
        c.collectSummary(mx, mfs, "txn_apply")
        c.collectSummary(mx, mfs, "raft_boltdb_storeLogs")
        c.collectSummary(mx, mfs, "raft_rpc_installSnapshot") // make sense for followers only
        c.collectSummary(mx, mfs, "raft_commitTime")          // make sense for leader only
        c.collectSummary(mx, mfs, "raft_leader_lastContact")  // make sense for leader only

        c.collectCounter(mx, mfs, "raft_apply", precision) // make sense for leader only
        c.collectCounter(mx, mfs, "raft_state_candidate", 1)
        c.collectCounter(mx, mfs, "raft_state_leader", 1)

        c.collectGaugeBool(mx, mfs, "autopilot_healthy", "autopilot_healthy_healthy")
        c.collectGaugeBool(mx, mfs, "server_isLeader", "server_isLeader_isLeader")
        c.collectGauge(mx, mfs, "autopilot_failure_tolerance", 1, "autopilot_failure_tolerance_failure_tolerance")
        c.collectGauge(mx, mfs, "raft_fsm_lastRestoreDuration", 1)
        c.collectGauge(mx, mfs, "raft_leader_oldestLogAge", 1, "raft_leader_oldestLogAge_oldestLogAge")
        c.collectGauge(mx, mfs, "raft_boltdb_freelistBytes", 1, "raft_boltdb_freelistBytes_freelistBytes")

        if isLeader, ok := c.isLeader(mfs); ok {
            if isLeader && !c.hasLeaderCharts {
                c.addLeaderCharts()
                c.hasLeaderCharts = true
            }
            if !isLeader && c.hasLeaderCharts {
                c.removeLeaderCharts()
                c.hasLeaderCharts = false
            }
            if !isLeader && !c.hasFollowerCharts {
                c.addFollowerCharts()
                c.hasFollowerCharts = true
            }
            if isLeader && c.hasFollowerCharts {
                c.removeFollowerCharts()
                c.hasFollowerCharts = false
            }
        }
    }

    c.collectGauge(mx, mfs, "system_licenseExpiration", 3600, "system_licenseExpiration_licenseExpiration")

    c.collectCounter(mx, mfs, "client_rpc", 1)
    c.collectCounter(mx, mfs, "client_rpc_exceeded", 1)
    c.collectCounter(mx, mfs, "client_rpc_failed", 1)

    c.collectGauge(mx, mfs, "runtime_alloc_bytes", 1, "runtime_alloc_bytes_alloc_bytes")
    c.collectGauge(mx, mfs, "runtime_sys_bytes", 1, "runtime_sys_bytes_sys_bytes")
    c.collectGauge(mx, mfs, "runtime_total_gc_pause_ns", 1, "runtime_total_gc_pause_ns_total_gc_pause_ns")

    return nil
}

func (c *Consul) isLeader(mfs prometheus.MetricFamilies) (bool, bool) {
    var mf *prometheus.MetricFamily
    for _, v := range []string{"server_isLeader_isLeader", "server_isLeader"} {
        if mf = mfs.GetGauge(c.promMetricNameWithHostname(v)); mf != nil {
            break
        }
        if mf = mfs.GetGauge(c.promMetricName(v)); mf != nil {
            break
        }
    }

    if mf == nil {
        return false, false
    }

    return mf.Metrics()[0].Gauge().Value() == 1, true
}

func (c *Consul) collectGauge(mx map[string]int64, mfs prometheus.MetricFamilies, name string, mul float64, aliases ...string) {
    var mf *prometheus.MetricFamily
    for _, v := range append(aliases, name) {
        if mf = mfs.GetGauge(c.promMetricNameWithHostname(v)); mf != nil {
            break
        }
        if mf = mfs.GetGauge(c.promMetricName(v)); mf != nil {
            break
        }
    }

    if mf == nil {
        return
    }

    v := mf.Metrics()[0].Gauge().Value()

    if !math.IsNaN(v) {
        mx[name] = int64(v * mul)
    }
}

func (c *Consul) collectGaugeBool(mx map[string]int64, mfs prometheus.MetricFamilies, name string, aliases ...string) {
    var mf *prometheus.MetricFamily
    for _, v := range append(aliases, name) {
        if mf = mfs.GetGauge(c.promMetricNameWithHostname(v)); mf != nil {
            break
        }
        if mf = mfs.GetGauge(c.promMetricName(v)); mf != nil {
            break
        }
    }

    if mf == nil {
        return
    }

    v := mf.Metrics()[0].Gauge().Value()

    if !math.IsNaN(v) {
        mx[name+"_yes"] = boolToInt(v == 1)
        mx[name+"_no"] = boolToInt(v == 0)
    }
}

func (c *Consul) collectCounter(mx map[string]int64, mfs prometheus.MetricFamilies, name string, mul float64) {
    mf := mfs.GetCounter(c.promMetricName(name))
    if mf == nil {
        return
    }

    v := mf.Metrics()[0].Counter().Value()

    if !math.IsNaN(v) {
        mx[name] = int64(v * mul)
    }
}

func (c *Consul) collectSummary(mx map[string]int64, mfs prometheus.MetricFamilies, name string) {
    mf := mfs.GetSummary(c.promMetricName(name))
    if mf == nil {
        return
    }

    m := mf.Metrics()[0]

    for _, q := range m.Summary().Quantiles() {
        v := q.Value()
        // MaxAge is 10 seconds (hardcoded)
        // https://github.com/hashicorp/go-metrics/blob/b6d5c860c07ef6eeec89f4a662c7b452dd4d0c93/prometheus/prometheus.go#L227
        if math.IsNaN(v) {
            v = 0
        }

        id := fmt.Sprintf("%s_quantile=%s", name, formatFloat(q.Quantile()))
        mx[id] = int64(v * precision * precision)
    }

    mx[name+"_sum"] = int64(m.Summary().Sum() * precision)
    mx[name+"_count"] = int64(m.Summary().Count())
}

func (c *Consul) promMetricName(name string) string {
    px := c.cfg.DebugConfig.Telemetry.MetricsPrefix
    return px + "_" + name
}

var forbiddenCharsReplacer = strings.NewReplacer(" ", "_", ".", "_", "=", "_", "-", "_", "/", "_")

// controlled by 'disable_hostname'
// https://developer.hashicorp.com/consul/docs/agent/config/config-files#telemetry-disable_hostname
func (c *Consul) promMetricNameWithHostname(name string) string {
    px := c.cfg.DebugConfig.Telemetry.MetricsPrefix
    node := forbiddenCharsReplacer.Replace(c.cfg.Config.NodeName)

    return px + "_" + node + "_" + name
}

func formatFloat(v float64) string {
    return strconv.FormatFloat(v, 'f', -1, 64)
}