tutor/tutor/utils.py

import click
import random
import shutil
import string
import subprocess

from . import exceptions
from . import fmt


def random_string(length):
    return "".join([random.choice(string.ascii_letters + string.digits) for _ in range(length)])

def common_domain(d1, d2):
    """
    Return the common domain between two domain names.

    Ex: "sub1.domain.com" and "sub2.domain.com" -> "domain.com"
    """
    components1 = d1.split(".")[::-1]
    components2 = d2.split(".")[::-1]
    common = []
    for c in range(0, min(len(components1), len(components2))):
        if components1[c] == components2[c]:
            common.append(components1[c])
        else:
            break
    return ".".join(common[::-1])

def docker_run(*command):
    return docker("run", "--rm", "-it", *command)

def docker(*command):
    if shutil.which("docker") is None:
        raise exceptions.TutorError("docker is not installed. Please follow instructions from https://docs.docker.com/install/")
    return execute("docker", *command)

def docker_compose(*command):
    if shutil.which("docker-compose") is None:
        raise exceptions.TutorError("docker-compose is not installed. Please follow instructions from https://docs.docker.com/compose/install/")
    return execute("docker-compose", *command)

def kubectl(*command):
    if shutil.which("kubectl") is None:
        raise exceptions.TutorError(
            "kubectl is not installed. Please follow instructions from https://kubernetes.io/docs/tasks/tools/install-kubectl/"
        )
    return execute("kubectl", *command)

def execute(*command):
    click.echo(fmt.command(" ".join(command)))
    with subprocess.Popen(command) as p:
        try:
            result = p.wait(timeout=None)
        except KeyboardInterrupt:
            p.kill()
            p.wait()
            raise
        except Exception:
            p.kill()
            p.wait()
            raise exceptions.TutorError("Command failed: {}".format(
                " ".join(command)
            ))
        if result > 0:
            raise exceptions.TutorError("Command failed with status {}: {}".format(
                result,
                " ".join(command)
            ))