Support absolute paths for in-context Dockerfiles

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

docker/api/build.py

@@ -332,10 +332,12 @@ def process_dockerfile(dockerfile, path):
 
     if (os.path.splitdrive(path)[0] != os.path.splitdrive(abs_dockerfile)[0] or
             os.path.relpath(abs_dockerfile, path).startswith('..')):
+        # Dockerfile not in context - read data to insert into tar later
         with open(abs_dockerfile, 'r') as df:
             return (
                 '.dockerfile.{0:x}'.format(random.getrandbits(160)),
                 df.read()
             )
-    else:
+
-        return (dockerfile, None)
+    # Dockerfile is inside the context - return path relative to context root
+    return (os.path.relpath(abs_dockerfile, path), None)

setup.py

@@ -9,12 +9,16 @@ import pip
 
 from setuptools import setup, find_packages
 
-if 'docker-py' in [x.project_name for x in pip.get_installed_distributions()]:
+try:
+    if 'docker-py' in [
+            x.project_name for x in pip.get_installed_distributions()]:
         print(
             'ERROR: "docker-py" needs to be uninstalled before installing this'
             ' package:\npip uninstall docker-py', file=sys.stderr
         )
         sys.exit(1)
+except AttributeError:
+    pass
 
 ROOT_DIR = os.path.dirname(__file__)
 SOURCE_DIR = os.path.join(ROOT_DIR)

tests/integration/api_build_test.py

@@ -452,7 +452,6 @@ class BuildTest(BaseAPIIntegrationTest):
                 'COPY . /src',
                 'WORKDIR /src',
             ]))
-        print(os.path.join(base_dir, 'custom.dockerfile'))
         img_name = random_name()
         self.tmp_imgs.append(img_name)
         stream = self.client.build(
@@ -472,3 +471,35 @@ class BuildTest(BaseAPIIntegrationTest):
         assert sorted(
             [b'.', b'..', b'file.txt', b'custom.dockerfile']
         ) == sorted(lsdata)
+
+    def test_build_in_context_abs_dockerfile(self):
+        base_dir = tempfile.mkdtemp()
+        self.addCleanup(shutil.rmtree, base_dir)
+        abs_dockerfile_path = os.path.join(base_dir, 'custom.dockerfile')
+        with open(os.path.join(base_dir, 'file.txt'), 'w') as f:
+            f.write('hello world')
+        with open(abs_dockerfile_path, 'w') as df:
+            df.write('\n'.join([
+                'FROM busybox',
+                'COPY . /src',
+                'WORKDIR /src',
+            ]))
+        img_name = random_name()
+        self.tmp_imgs.append(img_name)
+        stream = self.client.build(
+            path=base_dir, dockerfile=abs_dockerfile_path, tag=img_name,
+            decode=True
+        )
+        lines = []
+        for chunk in stream:
+            lines.append(chunk)
+        assert 'Successfully tagged' in lines[-1]['stream']
+
+        ctnr = self.client.create_container(img_name, 'ls -a')
+        self.tmp_containers.append(ctnr)
+        self.client.start(ctnr)
+        lsdata = self.client.logs(ctnr).strip().split(b'\n')
+        assert len(lsdata) == 4
+        assert sorted(
+            [b'.', b'..', b'file.txt', b'custom.dockerfile']
+        ) == sorted(lsdata)