Make parallel tasks interruptible with Ctrl-C

The concurrent.futures backport doesn't play well with
KeyboardInterrupt, so I'm using Thread and Queue instead.

Since thread pooling would likely be a pain to implement, I've just
removed `COMPOSE_MAX_WORKERS` for now. We'll implement it later if we
decide we need it.

Signed-off-by: Aanand Prasad <[email protected]>

compose/const.py

@@ -1,5 +1,4 @@
 
-DEFAULT_MAX_WORKERS = 20
 DEFAULT_TIMEOUT = 10
 LABEL_CONTAINER_NUMBER = 'com.docker.compose.container-number'
 LABEL_ONE_OFF = 'com.docker.compose.oneoff'

compose/utils.py

@@ -2,13 +2,11 @@
 import hashlib
 import json
 import logging
-import os
 import sys
 
 from docker.errors import APIError
-import concurrent.futures
-
-from .const import DEFAULT_MAX_WORKERS
+from Queue import Queue, Empty
+from threading import Thread
 
 
 log = logging.getLogger(__name__)
@@ -18,33 +16,40 @@ def parallel_execute(command, containers, doing_msg, done_msg, **options):
     """
     Execute a given command upon a list of containers in parallel.
     """
-    max_workers = os.environ.get('COMPOSE_MAX_WORKERS', DEFAULT_MAX_WORKERS)
     stream = codecs.getwriter('utf-8')(sys.stdout)
     lines = []
     errors = {}
 
     for container in containers:
         write_out_msg(stream, lines, container.name, doing_msg)
 
+    q = Queue()
+
     def container_command_execute(container, command, **options):
         try:
             getattr(container, command)(**options)
         except APIError as e:
             errors[container.name] = e.explanation
+        q.put(container)
+
+    for container in containers:
+        t = Thread(
+            target=container_command_execute,
+            args=(container, command),
+            kwargs=options,
+        )
+        t.daemon = True
+        t.start()
+
+    done = 0
 
-    with concurrent.futures.ThreadPoolExecutor(max_workers=max_workers) as executor:
-        future_container = {
-            executor.submit(
-                container_command_execute,
-                container,
-                command,
-                **options
-            ): container for container in containers
-        }
-
-        for future in concurrent.futures.as_completed(future_container):
-            container = future_container[future]
+    while done < len(containers):
+        try:
+            container = q.get(timeout=1)
             write_out_msg(stream, lines, container.name, done_msg)
+            done += 1
+        except Empty:
+            pass
 
     if errors:
         for container in errors:

docs/reference/overview.md

@@ -44,12 +44,6 @@ the `docker` daemon.
 
 Configures the path to the `ca.pem`, `cert.pem`, and `key.pem` files used for TLS verification. Defaults to `~/.docker`.
 
-### COMPOSE\_MAX\_WORKERS
-
-Configures the maximum number of worker threads to be used when executing
-commands in parallel. Only a subset of commands execute in parallel, `stop`,
-`kill` and `rm`.
-
 
 
 

requirements.txt

@@ -2,7 +2,6 @@ PyYAML==3.10
 docker-py==1.3.0
 dockerpty==0.3.4
 docopt==0.6.1
-futures==3.0.3
 requests==2.6.1
 six==1.7.3
 texttable==0.8.2

setup.py

@@ -33,7 +33,6 @@ def find_version(*file_paths):
     'docker-py >= 1.3.0, < 1.4',
     'dockerpty >= 0.3.4, < 0.4',
     'six >= 1.3.0, < 2',
-    'futures >= 3.0.3',
 ]