Files
container.training/bin/common.py
2016-02-29 21:24:32 +00:00

77 lines
2.6 KiB
Python
Executable File

import os
import subprocess
import sys
import time
import yaml
def COMPOSE_FILE():
if "COMPOSE_FILE" not in os.environ:
print("The $COMPOSE_FILE environment variable is not set. Aborting.")
exit(1)
return os.environ["COMPOSE_FILE"]
class ComposeFile(object):
def __init__(self, filename=None):
if filename is None:
filename = COMPOSE_FILE()
if not os.path.isfile(filename):
print("File {!r} does not exist. Aborting.".format(filename))
exit(1)
self.data = yaml.load(open(filename))
@property
def services(self):
if self.data.get("version") == "2":
return self.data["services"]
else:
return self.data
def save(self, filename=None):
if filename is None:
filename = COMPOSE_FILE()
with open(filename, "w") as f:
yaml.safe_dump(self.data, f, default_flow_style=False)
# Executes a bunch of commands in parallel, but no more than N at a time.
# This allows to execute concurrently a large number of tasks, without
# turning into a fork bomb.
# `parallelism` is the number of tasks to execute simultaneously.
# `commands` is a list of tasks to execute.
# Each task is itself a list, where the first element is a descriptive
# string, and the folloowing elements are the arguments to pass to Popen.
def parallel_run(commands, parallelism):
running = []
# While stuff is running, or we have stuff to run...
while commands or running:
# While there is stuff to run, and room in the pipe...
while commands and len(running)<parallelism:
command = commands.pop(0)
print("START {}".format(command[0]))
popen = subprocess.Popen(
command[1:], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
popen._desc = command[0]
running.append(popen)
must_sleep = True
for popen in running:
status = popen.poll()
if status is not None:
must_sleep = False
running.remove(popen)
if status==0:
print("OK {}".format(popen._desc))
else:
print("ERROR {} [Exit status: {}]"
.format(popen._desc, status))
output = "\n" + popen.communicate()[0].strip()
output = output.replace("\n", "\n| ")
print(output)
else:
print("WAIT ({} running, {} more to run)"
.format(len(running), len(commands)))
if must_sleep:
time.sleep(1)