125 lines
2.5 KiB
Go
125 lines
2.5 KiB
Go
package main
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"log"
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"os"
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"os/exec"
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"sync"
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)
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var config Config
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const sockfile = "/tmp/gopaper.sock"
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const pidfilePath = "/var/run/gopaper.pid"
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func main() {
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log.SetFlags(log.LstdFlags | log.Lshortfile)
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//MANAGE PIDFILES
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//check if pidfile already exists
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if _, err := os.Stat(pidfilePath); !errors.Is(err, os.ErrNotExist) {
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//if it does, kill the process and delete the pidfile
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prexPid, err := os.ReadFile(pidfilePath)
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if err != nil {
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log.Println("unable to read pre-existing pidfile", err)
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cleanExit(1)
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}
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//kill process
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err = exec.Command("kill", "-9", string(prexPid)).Run()
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if err != nil {
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log.Printf("unable to kill process %v\n", prexPid)
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cleanExit(1)
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}
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//remove pidfile
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err = os.Remove(pidfilePath)
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if err != nil {
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log.Printf("unable to remove pidfile %v\n", pidfilePath)
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cleanExit(1)
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}
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}
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//create new pidfile
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pid := os.Getpid()
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pidfile, err := os.Create(pidfilePath)
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if err != nil {
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log.Println("could not create pidfile", err)
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cleanExit(1)
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}
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buf := new(bytes.Buffer)
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err = binary.Write(buf, binary.LittleEndian, pid)
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if err != nil {
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}
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pidfile.Write(buf.Bytes())
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err = config.load()
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logfile, err := openLogfile()
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if err != nil {
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log.Println("failed to load config", err)
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cleanExit(1)
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}
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log.SetOutput(logfile)
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log.SetFlags(log.LstdFlags | log.Lshortfile | log.Lmicroseconds)
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log.Println("Welcome to GoPaper!")
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var waitGroup sync.WaitGroup
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waitGroup.Add(1)
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slideshowDir := make(chan string)
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func() {
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defer func() {
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if r := recover(); r != nil {
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log.Println("Panic recovered at top level", r)
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cleanExit(1)
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}
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}()
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go server(slideshowDir)
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go slideshow(slideshowDir)
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}()
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var dir string
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args := os.Args[1:]
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if len(args) > 0 {
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dir = args[0]
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} else {
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dir = config.Default
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}
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slideshowDir <- dir
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waitGroup.Wait()
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}
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func openLogfile() (*os.File, error) {
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//TODO: log rotation
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f, err := os.OpenFile(config.Cache+"/logfile", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
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if err != nil {
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return nil, err
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}
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return f, nil
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}
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func cleanExit(code int) {
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if code == 1 {
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log.Println("shutting down gracefully after errors")
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} else {
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log.Println("shutting down gracefully")
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}
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err := os.Remove(sockfile)
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if err != nil {
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log.Printf("unable to remove sockfile at %v. Error: %v\n", sockfile, err)
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} else {
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log.Println("sockfile removed")
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}
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err = os.Remove(pidfilePath)
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if err != nil {
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log.Printf("unable to remove pidfile at %v. Error: %v\n", pidfilePath, err)
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} else {
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log.Println("pidfile removed")
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}
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os.Exit(code)
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}
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