compose/compose/cli/log_printer.py

88 lines
2.6 KiB
Python

from __future__ import absolute_import
from __future__ import unicode_literals
import sys
from itertools import cycle
from . import colors
from .multiplexer import Multiplexer
from .utils import split_buffer
from compose import utils
class LogPrinter(object):
"""Print logs from many containers to a single output stream."""
def __init__(self, containers, output=sys.stdout, monochrome=False):
self.containers = containers
self.output = utils.get_output_stream(output)
self.monochrome = monochrome
def run(self):
if not self.containers:
return
prefix_width = max_name_width(self.containers)
generators = list(self._make_log_generators(self.monochrome, prefix_width))
for line in Multiplexer(generators).loop():
self.output.write(line)
def _make_log_generators(self, monochrome, prefix_width):
def no_color(text):
return text
if monochrome:
color_funcs = cycle([no_color])
else:
color_funcs = cycle(colors.rainbow())
for color_func, container in zip(color_funcs, self.containers):
generator_func = get_log_generator(container)
prefix = color_func(build_log_prefix(container, prefix_width))
yield generator_func(container, prefix, color_func)
def build_log_prefix(container, prefix_width):
return container.name_without_project.ljust(prefix_width) + ' | '
def max_name_width(containers):
"""Calculate the maximum width of container names so we can make the log
prefixes line up like so:
db_1 | Listening
web_1 | Listening
"""
return max(len(container.name_without_project) for container in containers)
def get_log_generator(container):
if container.has_api_logs:
return build_log_generator
return build_no_log_generator
def build_no_log_generator(container, prefix, color_func):
"""Return a generator that prints a warning about logs and waits for
container to exit.
"""
yield "{} WARNING: no logs are available with the '{}' log driver\n".format(
prefix,
container.log_driver)
yield color_func(wait_on_exit(container))
def build_log_generator(container, prefix, color_func):
# Attach to container before log printer starts running
stream = container.attach(stdout=True, stderr=True, stream=True, logs=True)
line_generator = split_buffer(stream, u'\n')
for line in line_generator:
yield prefix + line
yield color_func(wait_on_exit(container))
def wait_on_exit(container):
exit_code = container.wait()
return "%s exited with code %s\n" % (container.name, exit_code)