dps

#!/usr/bin/env python3

import csv
from io import StringIO
import re
import subprocess
import sys

FORMAT_ARGS = [
    '--format',
    '{{.Names}};{{.Status}};{{.Image}};{{.Ports}}'
]

RESET = '\033[0m'
RED = '\033[31m'
GREEN = '\033[32m'
YELLOW = '\033[33m'
CYAN = '\033[36m'
FUCHSIA = '\033[95m'


def _colourise(s, col):
    return '%s%s%s' % (col, s, RESET)


class DPSRow(object):
    def __init__(self, names, status, image, ports):
        self.names = names
        self.status = status
        self.ports = ports

        image_comps = image.split(':')
        self.image_name = image_comps[0]
        self.image_tag = image_comps[1] if len(image_comps) > 1 else 'latest'

    @staticmethod
    def _abbreviate_timings(status):
        """Shorten timings where possible for easier display"""
        status = status.replace('Less than an', '<')
        status = status.replace('Less than a', '<')
        status = status.replace('About an', '~1')
        status = status.replace('About a', '~1')
        status = status.replace(' ago', '')

        status = re.sub('([a-zA-Z]+)s', r'\1', status)
        status = status.replace(' second', 's')
        status = status.replace(' minute', 'm')
        status = status.replace(' hour', 'h')
        status = status.replace(' day', 'd')
        status = status.replace(' week', 'w')
        status = status.replace(' month', 'mo')
        status = status.replace(' year', 'y')

        return status

    @staticmethod
    def _colourise_status(status):
        if 'Exited' in status:
            status = 'Exited'

        if 'Restarting' in status:
            timing = DPSRow._abbreviate_timings(
                re.sub(r'Restarting \(.+\) ', '', status)
            )
            status = f'♻️ {timing}'

        if 'Up' not in status:
            return _colourise(status, RED)

        col = YELLOW if 'second' in status or 'minute' in status else GREEN
        status = status.replace(' (healthy)', '')
        status = DPSRow._abbreviate_timings(status)

        return _colourise(status, col)

    @staticmethod
    def _abbreviate_image(name):
        """
        Shorten long image names, such as by trimming length AWS ECR names
        down to a short representation

        12345789.dkr.ecr.{region}.amazon.aws.com -> ecr[123456789]
        """
        if '/' not in name:
            return name

        comps = name.split('/')
        repo = comps[0]
        img = comps[1]

        repo = re.sub(
            r'(\d+)\.dkr\.ecr\.[^\.]+\.amazonaws\.com', r'ecr[\1]', repo
        )

        return '{}/{}'.format(repo, img)

    def __str__(self):
        return '%-50s  %-16s  %-70s  %s' % (
            _colourise(self.names, CYAN),
            self._colourise_status(self.status),
            '%s:%s' % (
                _colourise(self._abbreviate_image(self.image_name), CYAN),
                _colourise(self.image_tag, FUCHSIA)
            ),
            self.ports
        )


def main():
    output = docker_ps(sys.argv[1:])
    fp = StringIO(output)

    reader = sorted(list(csv.reader(fp, delimiter=';')))
    for row in reader:
        print(DPSRow(*row))


def docker_ps(args=None):
    args = args or []
    res = subprocess.check_output(['docker', 'ps'] + FORMAT_ARGS + args)

    return res.decode('utf-8')


if __name__ == '__main__':
    main()