yanic/rrd/rrd.go

67 lines
1.3 KiB
Go

// Importer for global RRD stats
package rrd
import (
"bufio"
"io"
"os/exec"
"regexp"
"strconv"
"strings"
"time"
)
var linePattern = regexp.MustCompile("^<!-- ....-..-.. ..:..:.. [A-Z]+ / (\\d+) --> <row><v>([^<]+)</v><v>([^<]+)</v></row>")
type Dataset struct {
Time time.Time
Nodes float64
Clients float64
}
func Read(rrdFile string) chan Dataset {
out := make(chan Dataset)
cmd := exec.Command("rrdtool", "dump", rrdFile)
stdout, err := cmd.StdoutPipe()
if err != nil {
panic(err)
}
if err := cmd.Start(); err != nil {
panic(err)
}
r := bufio.NewReader(stdout)
found := false
go func() {
for {
// Read stdout by line
line, _, err := r.ReadLine()
if err == io.EOF {
break
}
str := strings.TrimSpace(string(line))
// Search for the start of the daily datasets
if !found {
found = strings.Contains(str, "<!-- 86400 seconds -->")
continue
}
if matches := linePattern.FindStringSubmatch(str); matches != nil && matches[2] != "NaN" {
seconds, _ := strconv.Atoi(matches[1])
nodes, _ := strconv.ParseFloat(matches[2], 64)
clients, _ := strconv.ParseFloat(matches[2], 64)
out <- Dataset{
Time: time.Unix(int64(seconds), 0),
Nodes: nodes,
Clients: clients,
}
}
}
close(out)
}()
return out
}