freeze requirements in Dockerfile

.github/dependabot.yaml

@@ -13,5 +13,13 @@ updates:
     labels: [ci]
     schedule:
       interval: monthly
-      time: "05:00"
-      timezone: Etc/UTC
+  # Update frozen requirements in repo2docker Dockerfile
+  - package-ecosystem: pip
+    directory: /
+    allow:
+      # need this to upgrade requirements.txt
+      # otherwise only direct dependencies in requirements.in will be updated
+      - dependency-type: all
+    labels: [dependencies]
+    schedule:
+      interval: monthly

Dockerfile

@@ -15,7 +15,7 @@ RUN cd /tmp/src && git clean -xfd && git status
 RUN mkdir /tmp/wheelhouse \
  && cd /tmp/wheelhouse \
  && pip install wheel \
- && pip wheel --no-cache-dir /tmp/src \
+ && pip wheel --no-cache-dir -r /tmp/src/requirements.txt \
  && ls -l /tmp/wheelhouse
 
 FROM alpine:${ALPINE_VERSION}

pyproject.toml

@@ -28,6 +28,8 @@ classifiers = [
     "Topic :: System :: Systems Administration",
 ]
 requires-python = ">=3.10"
+# after changing dependencies, run ./scripts/refreeze
+# so that the Dockerfile reflects the changes
 dependencies = [
     "charset-normalizer",
     "docker!=5.0.0",

requirements.in

@@ -0,0 +1,2 @@
+# freeze current requirements, used in Dockerfile
+.

requirements.txt

@@ -0,0 +1,48 @@
+#
+# This file is autogenerated by pip-compile with Python 3.12
+# by the following command:
+#
+#    ./scripts/refreeze
+#
+certifi==2026.2.25
+    # via requests
+charset-normalizer==3.4.5
+    # via
+    #   jupyter-repo2docker
+    #   requests
+docker==7.1.0
+    # via jupyter-repo2docker
+entrypoints==0.4
+    # via jupyter-repo2docker
+escapism==1.1.0
+    # via jupyter-repo2docker
+idna==3.11
+    # via requests
+iso8601==2.1.0
+    # via jupyter-repo2docker
+jinja2==3.1.6
+    # via jupyter-repo2docker
+jupyter-repo2docker @ file:///tmp/src
+    # via -r requirements.in
+markupsafe==3.0.3
+    # via jinja2
+packaging==26.0
+    # via jupyter-repo2docker
+python-json-logger==4.0.0
+    # via jupyter-repo2docker
+requests==2.32.5
+    # via
+    #   docker
+    #   jupyter-repo2docker
+ruamel-yaml==0.19.1
+    # via jupyter-repo2docker
+semver==3.0.4
+    # via jupyter-repo2docker
+toml==0.10.2
+    # via jupyter-repo2docker
+traitlets==5.14.3
+    # via jupyter-repo2docker
+urllib3==2.6.3
+    # via
+    #   docker
+    #   requests

scripts/refreeze

@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+"""
+Run pip-compile in docker to generate requirements.txt
+
+Should only need running when requirements change in pyproject.toml, which is uncommon.
+Dependabot should handle updating requirements.txt most of the time.
+"""
+
+from pathlib import Path
+from subprocess import run
+
+repo = Path(__file__).parents[1].resolve()
+
+
+def get_alpine_version():
+    """
+    Get the alpine version from our dockerfile
+
+    make sure we're running with the same version as the docker image.
+    """
+    dockerfile = repo / "Dockerfile"
+    with dockerfile.open() as f:
+        for line in f:
+            if "ALPINE_VERSION" in line:
+                return line.partition("=")[2].strip()
+    raise ValueError(f"Couldn't find ALPINE_VERSION= in {dockerfile}")
+
+
+def refreeze():
+    """
+    Run pip-compile in docker to generate requirements.txt
+    """
+
+    alpine_version = get_alpine_version()
+    run(
+        [
+            "docker",
+            "run",
+            "--rm",
+            f"-v{repo}:/tmp/src",
+            "-w/tmp/src",
+            "-eCUSTOM_COMPILE_COMMAND=./scripts/refreeze",
+            f"alpine:{alpine_version}",
+            "sh",
+            "-c",
+            """
+        apk add py3-pip git
+        python3 -m venv /tmp/venv
+        source /tmp/venv/bin/activate
+        pip install pip-tools
+        pip-compile
+        """,
+        ]
+    )
+
+
+if __name__ == "__main__":
+    refreeze()