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millics/main.go

143 lines
3 KiB
Go

package main
import (
"database/sql"
"encoding/json"
"fmt"
"html/template"
"log"
"net/http"
"os"
"time"
_ "modernc.org/sqlite"
)
type Config struct {
Port uint
}
type page struct {
Title string
SysLoad string
CpuUsage string
}
var db *sql.DB
var cpuUsage int8
var sysLoad float32
func main() {
var err error
// Load config
fmt.Println("Loading config.json")
cfgfile, err := os.Open("config.json")
if err != nil {
log.Fatal("Error reading config.json!")
return
}
defer cfgfile.Close()
decoder := json.NewDecoder(cfgfile)
Config := Config{}
err = decoder.Decode(&Config)
if err != nil {
log.Fatal("Can't decode config.json!")
return
}
db, err = sql.Open("sqlite", "database.db")
if err != nil {
log.Fatal(err)
}
fmt.Println("Getting loadAvg minutely from /proc/loadavg")
tickerLAvgMin := time.NewTicker(time.Minute)
done := make(chan bool)
go func() {
for {
select {
case <-done:
return
case t := <-tickerLAvgMin.C:
fmt.Printf("%v\n", t)
fetchLoadMinutely(t)
fetchCpuMinutely(t)
}
}
}()
fmt.Printf("Starting HTTP listener on :%v\n", Config.Port)
http.Handle("/static/", http.FileServer(http.Dir("./")))
http.HandleFunc("/", httpRootHandler)
err = http.ListenAndServe(fmt.Sprintf(":%v", Config.Port), nil)
if err != nil {
log.Fatal(err)
}
db.Close()
}
func httpRootHandler(w http.ResponseWriter, r *http.Request) {
t, _ := template.ParseFiles("index.html")
var p page
p.Title = "Millics"
p.SysLoad = fmt.Sprint(sysLoad)
p.CpuUsage = fmt.Sprint(cpuUsage)
t.Execute(w, p)
}
func initDB() {
// TODO: init DB
return
}
func fetchLoadMinutely(_t time.Time) {
file, err := os.Open("/proc/loadavg")
if err != nil {
fmt.Printf("Error fetching load: %v\n", err)
return
}
defer file.Close()
var lavg1, lavg5, lavg15 float32
ret, err := fmt.Fscanf(file, "%f %f %f", &lavg1, &lavg5, &lavg15)
if err != nil || ret != 3 {
fmt.Printf("Can't parse /proc/loadavg: %v\n", err)
return
}
sysLoad = lavg1
fmt.Printf("sysLoad: %v/%v/%v\n", lavg1, lavg5, lavg15)
return
}
var lastCpuTotal, lastCpuTotalIdle uint64 = 0, 0
func fetchCpuMinutely(_t time.Time) {
file, err := os.Open("/proc/stat")
if err != nil {
fmt.Printf("Error fetching CPU usage: %v\n", err)
return
}
defer file.Close()
var cpuUser, cpuNice, cpuSystem, cpuIdle, cpuIOWait, cpuIRQ, cpuSoftIRQ, cpuSteal uint64
var cpu string
ret, err := fmt.Fscanf(file, "%s %d %d %d %d %d %d %d %d", &cpu, &cpuUser, &cpuNice, &cpuSystem, &cpuIdle, &cpuIOWait, &cpuIRQ, &cpuSoftIRQ, &cpuSteal)
if err != nil || cpu != "cpu" || ret < 9 {
fmt.Printf("Can't parse /proc/stat: %v\n", err)
return
}
cpuTotal := cpuUser + cpuNice + cpuSystem + cpuIdle + cpuIOWait + cpuIRQ + cpuSoftIRQ + cpuSteal
cpuTotalIdle := cpuIdle + cpuIOWait
if lastCpuTotal != 0 && lastCpuTotalIdle != 0 {
cpuUsage = int8(100-float32((cpuTotalIdle-lastCpuTotalIdle))/float32((cpuTotal-lastCpuTotal))*100)
fmt.Printf("CPU: %v %%\n", cpuUsage)
}
lastCpuTotal = cpuTotal
lastCpuTotalIdle = cpuTotalIdle
}