Login to the Dockerhub using golang exec and pty, also, Fix for “cannot perform an interactive login from a non TTY device”

main.go

package main

import (
	"bytes"
	"io"
	"io/ioutil"
	"log"
	"os"
	"os/exec"

	"github.com/creack/pty"
)

func main() {

	executablePath, err := exec.LookPath("docker")

	if err != nil {
		log.Fatalf("could not found docker, err %v", err)
	}

	cmd := exec.Command(executablePath, "login", "docker.io")

	ptmx, err := pty.Start(cmd)
	if err != nil {
		panic(err)
	}

	// Make sure to close the pty at the end.
	defer func() { _ = ptmx.Close() }() // Best effort.

	id := os.Getenv("DOCKER_USERNAME")
	password := os.Getenv("DOCKER_USERNAME")

	go func() {
		ptmx.Write([]byte(id))
		ptmx.Write([]byte(password))
	}()

	var execOut bytes.Buffer
	io.Copy(&execOut, ptmx)

	count := len(id) + len(password)
	io.CopyN(ioutil.Discard, &execOut, int64(count))

	log.Println(execOut.String())
}

DOCKER_USERNAME=xxx DOCKER_PASSWORD=xxx go run -v ./main.go
command-line-arguments
2021/03/05 11:44:05 Authenticating with existing credentials...
Login Succeeded