What do I want?
To parse the output of the command which basically runs inside a POD
Shell Command:
bpftrace -p 13111 -e uretprobe:/ebpfKit/Examples/cpp/main:enqueue { @[pid] = count(); interval:s:1{ print(@); clear(@); }
Code Used to parse:
func RunUretprobe(tool string, loguretprobe chan Log, pid string, filepath string, funcname string) {
fmt.Println("checkpoint 1")
command := `uretprobe:` + filepath + `:` + funcname + `{ @[pid] = count(); }` +`interval:s:1` + `{ print(@); clear(@); }`
cmd := exec.Command("bpftrace", "-p", pid , "-e", command)
fmt.Println(cmd)
stdout, err := cmd.StdoutPipe()
if err != nil {
log.Fatal(err)
}
cmd.Start()
buf := bufio.NewReader(stdout)
fmt.Println("checkpoint 2")
for {
line, _, _ := buf.ReadLine()
parsedLine := strings.Fields(string(line))
fmt.Println("checkpoint 3 -", cmd)
if (len(parsedLine) > 0) && parsedLine[0] != "Attaching"{
s := strings.Split(parsedLine[0], "[")
sep := strings.Split(s[1], "]")
log := sep[0] + " " + parsedLine[1]
timest := 0.00
fmt.Println("count--", log)
n := Log{Fulllog: log, Pid: 1234, Time: timest, Probe: tool}
loguretprobe <- n
}
}
}
func main() {
loguretprobe := make(chan Log, 1)
go RunUretprobe("uretprobe", loguretprobe, "13111" , "/ebpfKit/Examples/cpp/main" , "enqueue")
go func() {
for val := range loguretprobe{
fmt.Println("Printing - ", val.Fulllog);
time.Sleep(time.Duration(1) * time.Second)
}
}()
for{
time.Sleep(time.Duration(1) * time.Second)
}
}
Problem:
When I manually enter the POD to run the above-written program, it works as required.
But, when I call RunUretprobe
from another program through gRPC client, it gives me the following broken command(I got the logs using kubectl logs "pod_name"
) as shown:
Expectation:
To get a single command as shown in the first picture so that it gets executed and later on get parsed.
After string "/n" gets added, so I removed the newline using the following to make it work as expected:
filepath = strings.Replace(filepath, "\n", "", -1)
funcname = strings.Replace(funcname, "\n", "", -1)
command := `uretprobe:` + filepath + `:` + funcname + `{ @[pid] = count(); }` +`interval:s:1` + `{ print(@); clear(@); }`