dummy.c

#include <stdio.h>
#include <unistd.h>
int main () {
    unsigned long long i;
	while (1) {
		printf("tick\n");
        for (i = 1; i != 0; i++){}
	}
}

minimum_test_case.go

package main

import (
	"bufio"
	"fmt"
	"io"
	_ "io/ioutil"
	"os"
	"os/exec"
)


type ExecMonitor struct {
	MonitorName  string
	ContainerIds []string
}

func main() {
	execMessages := make(chan []byte)
	execMonitor := ExecMonitor{}
	DockerComposeName := "docker-compose" // could be fig
	go execMonitor.Start(execMessages, DockerComposeName)
	for {
		select {
			case message := <-execMessages:
				fmt.Println("exec: ", string(message))
			// Other channels here
		}
	}
}

// Dummy
func getDockerContainerIds(dockerComposeName string) []string {
	_ = dockerComposeName
	ids := []string{"00f593c3086f4925b1574764b2e24e0ad62046789676b061ac15233100dc801d", "529f08ac44849b40687fb5696c50354e6da22b3d4c656b018085cd79e3b29b5f"}
	return ids
}


func (e ExecMonitor) Start(messages chan<- []byte, dockerComposeName string) {
	ids := getDockerContainerIds(dockerComposeName)
	// This program writes the names of any programs which are exec'd to stdout
	err := runCommandAndChannelOutput("./a.out", ids, messages)
	if err != nil {
		fmt.Println("Exec monitor failed")
		panic(err)
	}
}

func runCommandAndChannelOutput(commandname string, args []string, output chan<- []byte) error {
	command := exec.Command(commandname, args...)
	fmt.Print("running the command: ")
	fmt.Println(commandname, args)
	stdout, err := command.StdoutPipe()
	if err != nil {
		return err
	}
	stderr, err := command.StderrPipe()
	if err != nil {
		return err
	}

	go io.Copy(os.Stderr, stderr)
	command.Start()
	defer command.Wait()

	stdoutreader := bufio.NewReader(stdout)
	slurp := true
	for slurp {
		fetch := true
		line := []byte{}
		for fetch {
		fmt.Println("before reading line")
			partial_line, f, err := stdoutreader.ReadLine()
		fmt.Println("after reading line")
			fetch = f
			line = append(line, partial_line...)
			if err == io.EOF {
				slurp = false
				break
			} else if err != nil {
				return err
			}
		}
		if len(line) > 0 {
			output <- line
		}
	}
	return nil
}