nmon/cmd/nmon-devtools/fleet.go

package main

import (
	"fmt"
	"strconv"
	"strings"

	"github.com/gosnmp/gosnmp"

	"github.com/v10networks/nmon/internal/fixturegen"
	"github.com/v10networks/nmon/internal/profile"
	"github.com/v10networks/nmon/internal/snmprec"
)

// demoDevice is one simulated device of `devtools seed-demo`.
type demoDevice struct {
	name, site, role string
	kind             string // counters, big, router, ups, v1, down: what the gate and screenshots look for
	rec              *snmprec.Recording
	community        string
	version          string // v2c unless set
	hc               bool   // 64-bit counters, so history can be back-filled
}

// counterBase is added to every simulated 64-bit octet counter so that the
// back-filled history (about 3e13 bytes for 31 days at 100 Mbit/s) fits below
// the live counter and the join shows no reset.
const counterBase = 100_000_000_000_000

const (
	oidHCIn  = "1.3.6.1.2.1.31.1.1.1.6."
	oidHCOut = "1.3.6.1.2.1.31.1.1.1.10."
	oidUp    = "1.3.6.1.2.1.1.3.0"
)

// animate returns a copy of rec whose 64-bit octet counters advance at a steady
// per-port rate from counterBase and whose uptime ticks, so successive polls see
// traffic. Counters that already advance keep their rate and only gain the base.
func animate(rec *snmprec.Recording) *snmprec.Recording {
	recs := append([]snmprec.Record(nil), rec.Records()...)
	for i := range recs {
		r := &recs[i]
		switch {
		case r.Type == gosnmp.Counter64 && (strings.HasPrefix(r.OID, oidHCIn) || strings.HasPrefix(r.OID, oidHCOut)):
			recs[i] = animateCounter(*r)
		case r.OID == oidUp && r.Dyn == nil:
			if v, ok := r.Value.(uint32); ok {
				r.Dyn, r.Value = &snmprec.Dynamic{Rate: 100, Initial: uint64(v)}, nil
			}
		}
	}
	return snmprec.NewRecording(recs)
}

func animateCounter(r snmprec.Record) snmprec.Record {
	if r.Dyn != nil {
		d := *r.Dyn
		d.Initial += counterBase
		r.Dyn = &d
		return r
	}
	k, _ := strconv.Atoi(r.OID[strings.LastIndexByte(r.OID, '.')+1:])
	dir := 1
	if strings.HasPrefix(r.OID, oidHCOut) {
		dir = 2
	}
	mbps := 1 + (k*(31+7*dir))%90
	r.Dyn = &snmprec.Dynamic{Rate: float64(mbps) * 125_000, Initial: counterBase + uint64(k)*1_000_000_000}
	r.Value = nil
	return r
}

// profileDevice builds a device that a shipped profile matches, with traffic.
func profileDevice(set *profile.Set, prof, name, site, role, kind string, ports int) (demoDevice, error) {
	spec, ok := fixturegen.SpecFor(prof)
	if !ok {
		return demoDevice{}, fmt.Errorf("no fixture spec for profile %q", prof)
	}
	res, ok := set.Lookup(prof)
	if !ok {
		return demoDevice{}, fmt.Errorf("no profile %q", prof)
	}
	spec.SysName = name
	if ports > 0 {
		spec.Ports = ports
	}
	rec, err := fixturegen.FromProfile(res, spec)
	if err != nil {
		return demoDevice{}, fmt.Errorf("%s: %w", name, err)
	}
	return demoDevice{name: name, site: site, role: role, kind: kind, rec: animate(rec), community: "public", hc: true}, nil
}

// buildFleet is the small network used for live screenshots: a 48-port switch,
// routers, a firewall, a UPS, one 32-bit device, the counters fixture and one
// device whose agent is stopped after seeding, so it reads as down.
func buildFleet(set *profile.Set, countersRec string) ([]demoDevice, error) {
	counters, err := snmprec.Load(countersRec)
	if err != nil {
		return nil, err
	}
	fleet := []demoDevice{{
		name: "yyz1-edge1", site: "yyz1", role: "edge", kind: "counters", rec: animate(counters), community: "public", hc: true,
	}}
	for _, p := range []struct {
		prof, name, site, role, kind string
		ports                        int
	}{
		{"cisco-ios", "yyz1-acc01", "yyz1", "access", "big", 48},
		{"cisco-ios", "yyz1-acc02", "yyz1", "access", "router", 24},
		{"cisco-ios", "ott1-acc02", "ott1", "access", "down", 24}, // its agent is stopped once seeding is done
		{"juniper-junos", "yyz1-core1", "yyz1", "core", "router", 0},
		{"arista-eos", "yul1-core1", "yul1", "core", "router", 0},
		{"mikrotik-routeros", "ott1-gw1", "ott1", "gateway", "router", 0},
		{"fortigate", "yyz1-fw1", "yyz1", "firewall", "router", 0},
		{"apc-ups", "yyz1-ups1", "yyz1", "power", "ups", 0},
	} {
		d, err := profileDevice(set, p.prof, p.name, p.site, p.role, p.kind, p.ports)
		if err != nil {
			return nil, err
		}
		fleet = append(fleet, d)
	}
	// 32-bit counters on 1 Gbit/s ports: the API flags them unreliable and the UI never graphs them.
	v1 := fixturegen.Generic(fixturegen.Options{Ports: 12, SysName: "yul1-acc03", Counters: true, NamePattern: "Fa0/%d"})
	fleet = append(fleet, demoDevice{
		name: "yul1-acc03", site: "yul1", role: "access", kind: "v1", rec: v1, community: "nmon-v1", version: "v1",
	})
	return fleet, nil
}