reaction/main.go

109 lines
2.3 KiB
Go

package main
import (
"bufio"
"flag"
"log"
"os"
"os/exec"
"strings"
"time"
)
// Executes a command and channel-send its stdout
func cmdStdout(commandline []string) chan string {
lines := make(chan string)
go func() {
cmd := exec.Command(commandline[0], commandline[1:]...)
stdout, err := cmd.StdoutPipe()
if err != nil {
log.Fatal("couldn't open stdout on command:", err)
}
if err := cmd.Start(); err != nil {
log.Fatal("couldn't start command:", err)
}
defer stdout.Close()
scanner := bufio.NewScanner(stdout)
for scanner.Scan() {
lines <- scanner.Text()
}
close(lines)
}()
return lines
}
// Whether one of the filter's regexes is matched on a line
func (f *Filter) match(line string) string {
for _, regex := range f.compiledRegex {
if matches := regex.FindStringSubmatch(line); matches != nil {
match := matches[regex.SubexpIndex(f.patternName)]
log.Printf("INFO %s.%s: match `%v`\n", f.stream.name, f.name, match)
return match
}
}
return ""
}
func (f *Filter) execActions(match string) {
for _, a := range f.Actions {
go a.exec(match)
}
}
func (a *Action) exec(match string) {
if a.afterDuration != 0 {
time.Sleep(a.afterDuration)
}
computedCommand := make([]string, 0, len(a.Cmd))
for _, item := range a.Cmd {
computedCommand = append(computedCommand, strings.ReplaceAll(item, a.filter.patternWithBraces, match))
}
log.Printf("INFO %s.%s.%s: run %s\n", a.filter.stream.name, a.filter.name, a.name, computedCommand)
cmd := exec.Command(computedCommand[0], computedCommand[1:]...)
if ret := cmd.Run(); ret != nil {
log.Printf("ERR %s.%s.%s: run %s, code %s\n", a.filter.stream.name, a.filter.name, a.name, computedCommand, ret)
}
}
func (s *Stream) handle() {
log.Printf("INFO %s: start %s\n", s.name, s.Cmd)
lines := cmdStdout(s.Cmd)
for line := range lines {
for _, filter := range s.Filters {
if match := filter.match(line); match != "" {
filter.execActions(match)
}
}
}
}
func main() {
confFilename := flag.String("c", "", "configuration file. see an example at https://framagit.org/ppom/reaction/-/blob/main/reaction.yml")
flag.Parse()
if *confFilename == "" {
flag.PrintDefaults()
os.Exit(2)
}
conf := parseConf(*confFilename)
for _, stream := range conf.Streams {
go stream.handle()
}
// Infinite wait
<-make(chan bool)
}