Add stream and timestamp args to client.build

Author: peteristhegreat

docker/models/images.py

@@ -217,7 +217,7 @@ def reload(self):
 class ImageCollection(Collection):
     model = Image
 
-    def build(self, **kwargs):
+    def build(self, stream=False, timestamp=False, **kwargs):
         """
         Build an image and return it. Similar to the ``docker build``
         command. Either ``path`` or ``fileobj`` must be set.
@@ -245,6 +245,10 @@ def build(self, **kwargs):
             custom_context (bool): Optional if using ``fileobj``
             encoding (str): The encoding for a stream. Set to ``gzip`` for
                 compressing
+            stream (bool): Print the build output to stdout and stderr while 
+                the build runs
+            timestamp (bool): Prefix build output stream with a timestamp 
+                "%Y-%m-%d %H:%M:%S"
             pull (bool): Downloads any updates to the FROM image in Dockerfiles
             forcerm (bool): Always remove intermediate containers, even after
                 unsuccessful builds
@@ -300,9 +304,20 @@ def build(self, **kwargs):
         image_id = None
         result_stream, internal_stream = itertools.tee(json_stream(resp))
         for chunk in internal_stream:
+            if timestamp:
+                timestamp_str = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
             if 'error' in chunk:
+                if stream:
+                    if timestamp:
+                        print(timestamp_str, "- ", end='', file=sys.stderr)
+                    print("Error:", chunk['error'].strip(), flush=True, file=sys.stderr))
                 raise BuildError(chunk['error'], result_stream)
             if 'stream' in chunk:
+                if stream:
+                    for line in chunk["stream"].splitlines():
+                        if timestamp:
+                            print(timestamp_str, "- ", end='')
+                        print(line.strip(), flush=True)
                 match = re.search(
                     r'(^Successfully built |sha256:)([0-9a-f]+)$',
                     chunk['stream']

tests/unit/api_build_test.py

@@ -28,6 +28,21 @@ def test_build_container(self):
 
         self.client.build(fileobj=script)
 
+    def test_build_container_with_stream_with_timestamp(self):
+        script = io.BytesIO(
+            "\n".join(
+                [
+                    "FROM busybox",
+                    "RUN mkdir -p /tmp/test",
+                    "EXPOSE 8080",
+                    "ADD https://dl.dropboxusercontent.com/u/20637798/silence.tar.gz"
+                    " /tmp/silence.tar.gz",
+                ]
+            ).encode("ascii")
+        )
+
+        self.client.build(fileobj=script, stream=True, timestamp=True)
+
     def test_build_container_pull(self):
         script = io.BytesIO(
             "\n".join(