Merge pull request #552 from aseering/main

Add support for custom contexts

Author: openshift-merge-bot[bot]

podman/domain/images_build.py

@@ -34,7 +34,7 @@ def build(self, **kwargs) -> tuple[Image, Iterator[bytes]]:
             nocache (bool) – Don’t use the cache when set to True
             rm (bool) – Remove intermediate containers. Default True
             timeout (int) – HTTP timeout
-            custom_context (bool) – Optional if using fileobj (ignored)
+            custom_context (bool) – Optional if using fileobj
             encoding (str) – The encoding for a stream. Set to gzip for compressing (ignored)
             pull (bool) – Downloads any updates to the FROM image in Dockerfile
             forcerm (bool) – Always remove intermediate containers, even after unsuccessful builds
@@ -82,7 +82,21 @@ def build(self, **kwargs) -> tuple[Image, Iterator[bytes]]:
 
         body = None
         path = None
-        if "fileobj" in kwargs:
+        if kwargs.get("custom_context"):
+            if "fileobj" not in kwargs:
+                raise PodmanError(
+                    "Custom context requires fileobj to be set to a binary file-like object containing a build-directory tarball."
+                )
+            if "dockerfile" not in kwargs:
+                # TODO: Scan the tarball for either a Dockerfile or a Containerfile.
+                # This could be slow if the tarball is large,
+                # and could require buffering/copying the tarball if `fileobj` is not seekable.
+                # As a workaround for now, don't support omitting the filename.
+                raise PodmanError(
+                    "Custom context requires specifying the name of the Dockerfile (typically 'Dockerfile' or 'Containerfile')."
+                )
+            body = kwargs["fileobj"]
+        elif "fileobj" in kwargs:
             path = tempfile.TemporaryDirectory()  # pylint: disable=consider-using-with
             filename = pathlib.Path(path.name) / params["dockerfile"]
 

podman/tests/integration/test_images.py

@@ -23,7 +23,7 @@
 import podman.tests.integration.base as base
 from podman import PodmanClient
 from podman.domain.images import Image
-from podman.errors import APIError, ImageNotFound
+from podman.errors import APIError, ImageNotFound, PodmanError
 
 
 # @unittest.skipIf(os.geteuid() != 0, 'Skipping, not running as root')
@@ -144,6 +144,42 @@ def test_build(self):
         self.assertIsNotNone(image)
         self.assertIsNotNone(image.id)
 
+    def test_build_with_context(self):
+        context = io.BytesIO()
+        with tarfile.open(fileobj=context, mode="w") as tar:
+
+            def add_file(name: str, content: str):
+                binary_content = content.encode("utf-8")
+                fileobj = io.BytesIO(binary_content)
+                tarinfo = tarfile.TarInfo(name=name)
+                tarinfo.size = len(binary_content)
+                tar.addfile(tarinfo, fileobj)
+
+            # Use a non-standard Dockerfile name to test the 'dockerfile' argument
+            add_file(
+                "MyDockerfile", ("FROM quay.io/libpod/alpine_labels:latest\nCOPY example.txt .\n")
+            )
+            add_file("example.txt", "This is an example file.\n")
+
+        # Rewind to the start of the generated file so we can read it
+        context.seek(0)
+
+        with self.assertRaises(PodmanError) as e:
+            # If requesting a custom context, must provide the context as `fileobj`
+            self.client.images.build(custom_context=True, path='invalid')
+
+        with self.assertRaises(PodmanError) as e:
+            # If requesting a custom context, currently must specify the dockerfile name
+            self.client.images.build(custom_context=True, fileobj=context)
+
+        image, stream = self.client.images.build(
+            fileobj=context,
+            dockerfile="MyDockerfile",
+            custom_context=True,
+        )
+        self.assertIsNotNone(image)
+        self.assertIsNotNone(image.id)
+
     @unittest.skipIf(platform.architecture()[0] == "32bit", "no 32-bit image available")
     def test_pull_stream(self):
         generator = self.client.images.pull("ubi8", tag="latest", stream=True)