Catch APIError while printing container logs

Signed-off-by: Joffrey F <joffrey@docker.com>

compose/cli/log_printer.py

@@ -6,6 +6,7 @@ from collections import namedtuple
 from itertools import cycle
 from threading import Thread
 
+from docker.errors import APIError
 from six.moves import _thread as thread
 from six.moves.queue import Empty
 from six.moves.queue import Queue
@@ -176,8 +177,14 @@ def build_log_generator(container, log_args):
 
 
 def wait_on_exit(container):
-    exit_code = container.wait()
-    return "%s exited with code %s\n" % (container.name, exit_code)
+    try:
+        exit_code = container.wait()
+        return "%s exited with code %s\n" % (container.name, exit_code)
+    except APIError as e:
+        return "Unexpected API error for %s (HTTP code %s)\nResponse body:\n%s\n" % (
+            container.name, e.response.status_code,
+            e.response.text or '[empty]'
+        )
 
 
 def start_producer_thread(thread_args):

tests/unit/cli/log_printer_test.py

@@ -4,7 +4,9 @@ from __future__ import unicode_literals
 import itertools
 
 import pytest
+import requests
 import six
+from docker.errors import APIError
 from six.moves.queue import Queue
 
 from compose.cli.log_printer import build_log_generator
@@ -56,6 +58,26 @@ def test_wait_on_exit():
     assert expected == wait_on_exit(mock_container)
 
 
+def test_wait_on_exit_raises():
+    status_code = 500
+
+    def mock_wait():
+        resp = requests.Response()
+        resp.status_code = status_code
+        raise APIError('Bad server', resp)
+
+    mock_container = mock.Mock(
+        spec=Container,
+        name='cname',
+        wait=mock_wait
+    )
+
+    expected = 'Unexpected API error for {} (HTTP code {})\n'.format(
+        mock_container.name, status_code,
+    )
+    assert expected in wait_on_exit(mock_container)
+
+
 def test_build_no_log_generator(mock_container):
     mock_container.has_api_logs = False
     mock_container.log_driver = 'none'