Graph /proc/meminfo with Go and Graphite

meminfo.go

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"time"
)

const meminfo = "/proc/meminfo"

const (
	ErrOpen = iota + 2
	ErrConv
)

func main() {
	for {
		f, err := os.Open(meminfo)
		if err != nil {
			os.Exit(ErrOpen)
		}
		s := bufio.NewScanner(f)
		for s.Scan() {
			parts := bytes.Split(s.Bytes(), []byte(":"))
			k := string(bytes.Trim(bytes.ToLower(bytes.Map(parensToUnderscores, parts[0])), "_"))
			v := bytes.Trim(parts[1], " ")
			if v[0] == byte('0') {
				continue
			}
			kb, err := strconv.Atoi(string(bytes.Split(v, []byte(" "))[0]))
			if err != nil {
				log.Println(err)
				os.Exit(ErrConv)
			}
			fmt.Printf("memmon.%s %d %d\n", k, kb/1024, time.Now().Unix())
		}
		f.Close()
		time.Sleep(time.Second)
	}
}

func parensToUnderscores(r rune) rune {
	if r == '(' || r == ')' {
		return '_'
	}
	return r
}

record.sh

#!/bin/bash

go run meminfo.go | nc localhost 2003

start_graphite_in_docker.sh

#/bin/bash

docker run --rm -d  --name graphite  -p 8080:80  -p 2003-2004:2003-2004  -p 2023-2024:2023-2024  -p 8125:8125/udp  -p 8126:8126  graphiteapp/graphite-statsd