Add a docker registry integration test with real registry

.github/workflows/test.yml

@@ -65,6 +65,7 @@ jobs:
           - unit
           - venv
           - contentproviders
+          - registry
           # Playwright test
           - ui
         include:
@@ -73,22 +74,9 @@ jobs:
             python_version: "3.9"
             repo_type: venv
 
-    services:
-      # So that we can test this in PRs/branches
-      local-registry:
-        image: registry:2
-        ports:
-          - 5000:5000
-
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-        with:
-          # Allows pushing to registry on localhost:5000
-          driver-opts: network=host
-
       - uses: actions/setup-python@v5
         with:
           python-version: "${{ matrix.python_version }}"

repo2docker/app.py

@@ -37,7 +37,7 @@ from .buildpacks import (
     RBuildPack,
 )
 from .engine import BuildError, ContainerEngineException, ImageLoadError
-from .utils import ByteSpecification, R2dState, chdir, get_platform
+from .utils import ByteSpecification, R2dState, chdir, get_platform, get_free_port
 
 
 class Repo2Docker(Application):
@@ -660,7 +660,7 @@ class Repo2Docker(Application):
                 container_port = int(container_port_proto.split("/", 1)[0])
             else:
                 # no port specified, pick a random one
-                container_port = host_port = str(self._get_free_port())
+                container_port = host_port = str(get_free_port())
                 self.ports = {f"{container_port}/tcp": host_port}
             self.port = host_port
             # To use the option --NotebookApp.custom_display_url
@@ -744,17 +744,6 @@ class Repo2Docker(Application):
             if exit_code:
                 sys.exit(exit_code)
 
-    def _get_free_port(self):
-        """
-        Hacky method to get a free random port on local host
-        """
-        import socket
-
-        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        s.bind(("", 0))
-        port = s.getsockname()[1]
-        s.close()
-        return port
 
     def find_image(self):
         # if this is a dry run it is Ok for dockerd to be unreachable so we

repo2docker/utils.py

@@ -1,4 +1,5 @@
 import os
+import socket
 import platform
 import re
 import subprocess
@@ -545,3 +546,14 @@ def get_platform():
     else:
         warnings.warn(f"Unexpected platform '{m}', defaulting to linux/amd64")
         return "linux/amd64"
+
+
+def get_free_port():
+    """
+    Hacky method to get a free random port on local host
+    """
+    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    s.bind(("", 0))
+    port = s.getsockname()[1]
+    s.close()
+    return port

tests/registry/Dockerfile

@@ -0,0 +1,2 @@
+# Smallest possible dockerfile, used only for building images to be tested
+FROM scratch

tests/registry/test_registry.py

@@ -0,0 +1,50 @@
+from pathlib import Path
+import subprocess
+import pytest
+from repo2docker.__main__ import make_r2d
+from repo2docker.utils import get_free_port
+import time
+import requests
+import secrets
+
+HERE = Path(__file__).parent
+
+@pytest.fixture
+def registry():
+    port = get_free_port()
+    cmd = [
+        "docker", "run", "-it", "-p", f"{port}:5000", "registry:3.0.0-rc.3"
+    ]
+    proc = subprocess.Popen(cmd)
+    health_url = f'http://localhost:{port}/v2'
+    # Wait for the registry to actually come up
+    for i in range(10):
+        try:
+            resp = requests.get(health_url)
+            if resp.status_code in (401, 200):
+                break
+        except requests.ConnectionError:
+            # The service is not up yet
+            pass
+        time.sleep(i)
+    else:
+        raise TimeoutError("Test registry did not come up in time")
+
+    try:
+        yield f"localhost:{port}"
+    finally:
+        proc.terminate()
+        proc.wait()
+
+
+def test_registry(registry):
+    image_name = f"{registry}/{secrets.token_hex(8)}:latest"
+    r2d = make_r2d([
+        "--image", image_name,
+        "--push", "--no-run", str(HERE)
+    ])
+
+    r2d.start()
+
+    proc = subprocess.run(["docker", "manifest", "inspect", "--insecure", image_name])
+    assert proc.returncode == 0

tests/unit/test_docker.py

@@ -22,43 +22,3 @@ def test_git_credential_env():
         .strip()
     )
     assert out == credential_env
-
-
-class MockDockerEngine(DockerEngine):
-    def __init__(self, *args, **kwargs):
-        self._apiclient = Mock()
-
-
-def test_docker_push_no_credentials():
-    engine = MockDockerEngine()
-
-    engine.push("image")
-
-    assert len(engine._apiclient.method_calls) == 1
-    engine._apiclient.push.assert_called_once_with("image", stream=True)
-
-
-def test_docker_push_dict_credentials():
-    engine = MockDockerEngine()
-    engine.registry_credentials = {"username": "abc", "password": "def"}
-
-    engine.push("image")
-
-    assert len(engine._apiclient.method_calls) == 2
-    engine._apiclient.login.assert_called_once_with(username="abc", password="def")
-    engine._apiclient.push.assert_called_once_with("image", stream=True)
-
-
-def test_docker_push_env_credentials():
-    engine = MockDockerEngine()
-    with patch.dict(
-        "os.environ",
-        {
-            "CONTAINER_ENGINE_REGISTRY_CREDENTIALS": '{"username": "abc", "password": "def"}'
-        },
-    ):
-        engine.push("image")
-
-    assert len(engine._apiclient.method_calls) == 2
-    engine._apiclient.login.assert_called_once_with(username="abc", password="def")
-    engine._apiclient.push.assert_called_once_with("image", stream=True)