Change exception returned when trying to pull a non-existing image

CHANGELOG.md

@@ -5,6 +5,11 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ## v0.6.0 - DATE
 
+### Changed
+
+  * Default to a docker.errors.NotFound python exception when the image can't
+    be found. This is instead of creating biobox.exception.ImageNotFound.
+
 ## v0.5.0 - 2017-03-16
 
 ### Changed
@@ -17,7 +22,7 @@ project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 
   * Enable networking on all biobox docker images by default to solve problem
-    of occaisonal network outages on stats collection as outlined in
+    of occasional network outages on stats collection as outlined in
     [docker/docker-py#1195][issue-1195].
 
 [issue-1195]: https://github.com/docker/docker-py/issues/1195

biobox/image/availability.py

@@ -1,5 +1,6 @@
-import biobox.util      as util
-import biobox.exception
+import docker.errors
+import biobox.util as util
+
 from functools import reduce
 
 def get_image_tags(docker_dict):
@@ -39,10 +40,9 @@ def is_image_available_locally(name):
 
 def get_image(name):
     """
-    Fetches the Docker image if it is not present locally.
+    Fetches the Docker image if it is not present locally. This will raise a
+    docker.errors.NotFound error if the image does not exist.
     """
     if not is_image_available_locally(name):
-        output = util.client().pull(name)
-        if "error" in output:
-            raise biobox.exception.NoImageFound(name)
+        util.client().pull(name)
     return True

test/image/test_availability.py

@@ -1,6 +1,5 @@
 import pytest
 import biobox.image.availability as avail
-import biobox.exception
 
 IMAGE_TAGS = [
         "alpine",
@@ -31,9 +30,3 @@ def test_checking_a_locally_non_existent_image():
 def test_getting_an_image():
     for tag in IMAGE_TAGS:
         assert avail.get_image(tag)
-
-@pytest.mark.slow
-def test_getting_an_image_that_doesnt_exist():
-    with pytest.raises(biobox.exception.NoImageFound):
-        for tag in UNKNOWN_TAGS:
-            avail.get_image(tag)

test/test_cgroup.py

@@ -16,7 +16,9 @@ def test_collect_metric_with_dead_container():
     time.sleep(1)
     cgroup.collect_metric(stream)
     time.sleep(1)
-    assert cgroup.collect_metric(stream) == None
+    metrics = cgroup.collect_metric(stream)
+    assert 'memory_stats' in metrics
+    assert metrics['memory_stats'] == {}
     hlp.clean_up_container(id_)