PYT-3173: download wheels for the Python agent

The Python agent has started distributing prebuilt wheels in
v10.0.0 . This change updates the build to use those wheels. Some
advantages of wheels include
  * no longer needing a separate build stage for each supported
    Python version
  * easier reproducibility, since we're downloading prebuilt
    packages instead of building them in a slim-bookworm image.
  * now supporting Alpine and other musllibc environments!

src/python/Dockerfile

@@ -1,59 +1,16 @@
 # Contrast Security, Inc licenses this file to you under the Apache 2.0 License.
 # See the LICENSE file in the project root for more information.
 
-FROM python:3.13-slim-bookworm AS builder-313
-ARG VERSION=9.8.0
+FROM python:3.9-slim-bookworm AS builder
+ARG VERSION=10.0.2
 RUN set -xe \
   && apt-get update \
-  && apt-get install -y build-essential autoconf
+  && apt-get install unzip
+COPY ./src/python/fetch-python.sh .
 RUN set -xe \
   && mkdir -p /contrast \
   && echo ${VERSION} \
-  && pip install --target=/contrast "contrast-agent==${VERSION}" \
-  && echo "{ \"version\": \"${VERSION}\" }" > /contrast/image-manifest.json
-
-FROM python:3.12-slim-bookworm AS builder-312
-ARG VERSION=9.8.0
-RUN set -xe \
-  && apt-get update \
-  && apt-get install -y build-essential autoconf
-RUN set -xe \
-  && mkdir -p /contrast \
-  && echo ${VERSION} \
-  && pip install --target=/contrast "contrast-agent==${VERSION}" \
-  && echo "{ \"version\": \"${VERSION}\" }" > /contrast/image-manifest.json
-
-FROM python:3.11-slim-bookworm AS builder-311
-ARG VERSION=9.8.0
-RUN set -xe \
-  && apt-get update \
-  && apt-get install -y build-essential autoconf
-RUN set -xe \
-  && mkdir -p /contrast \
-  && echo ${VERSION} \
-  && pip install --target=/contrast "contrast-agent==${VERSION}" \
-  && echo "{ \"version\": \"${VERSION}\" }" > /contrast/image-manifest.json
-
-FROM python:3.10-slim-bookworm AS builder-310
-ARG VERSION=9.8.0
-RUN set -xe \
-  && apt-get update \
-  && apt-get install -y build-essential autoconf
-RUN set -xe \
-  && mkdir -p /contrast \
-  && echo ${VERSION} \
-  && pip install --target=/contrast "contrast-agent==${VERSION}" \
-  && echo "{ \"version\": \"${VERSION}\" }" > /contrast/image-manifest.json
-
-FROM python:3.9-slim-bookworm AS builder-39
-ARG VERSION=9.8.0
-RUN set -xe \
-  && apt-get update \
-  && apt-get install -y build-essential autoconf
-RUN set -xe \
-  && mkdir -p /contrast \
-  && echo ${VERSION} \
-  && pip install --target=/contrast "contrast-agent==${VERSION}" \
+  && ./fetch-python.sh ${VERSION} /contrast \
   && echo "{ \"version\": \"${VERSION}\" }" > /contrast/image-manifest.json
 
 
@@ -64,13 +21,9 @@ RUN set -xe \
   && adduser -u 1001 -G custom-group -D -H custom-user
 
 COPY ./src/shared/entrypoint.sh /entrypoint.sh
-COPY --from=builder-313 /contrast /contrast
-COPY --from=builder-312 /contrast /contrast
-COPY --from=builder-311 /contrast /contrast
-COPY --from=builder-310 /contrast /contrast
-COPY --from=builder-39 /contrast /contrast
+COPY --from=builder /contrast /contrast
 
-ARG VERSION=9.8.0
+ARG VERSION=10.0.2
 ENV CONTRAST_MOUNT_PATH=/contrast-init \
   CONTRAST_VERSION=${VERSION} \
   CONTRAST_AGENT_TYPE=python

src/python/fetch-python.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+
+set -o nounset
+set -o pipefail
+set -o errexit
+
+if [ "${1-}" == "--help" ] || [ "${1-}" == "-h" ]; then
+    echo "Usage: $0 [version] [destination]"
+    echo "  [version]      : Optional. The version of the contrast-agent to download (e.g., 'latest' or '1.2.3'). Defaults to latest."
+    echo "  [destination]  : Optional. The directory to save the downloaded files. Defaults to /agents/python/{version}/."
+    exit 1
+fi
+
+VERSION=${1:-"latest"}
+if [ "$VERSION" == "latest" ]; then
+    VERSION=$(
+        python3 -m pip index versions "contrast-agent" --only-binary :all: \
+        | sed -n 's/.*contrast-agent (\(.*\)).*/\1/p'
+    )
+fi
+
+SCRIPT_DIR=$(dirname "$(realpath "$0")")
+REPO_ROOT="$SCRIPT_DIR/../.."
+DESTINATION=${2:-"$REPO_ROOT/agents/python/$VERSION/"}
+
+PLATFORMS="manylinux_2_17_x86_64 musllinux_1_2_x86_64"
+PYTHON_VERSIONS="39 310 311 312 313"
+
+TEMP_DIR=$(mktemp -d)
+
+for platform in $PLATFORMS; do
+    for py_version in $PYTHON_VERSIONS; do
+        echo "Downloading wheels for $platform $py_version";
+        python3 -m pip download \
+        --dest "$TEMP_DIR" \
+        --only-binary :all: \
+        --platform "$platform" \
+        --python-version "$py_version" \
+        "contrast-agent==$VERSION";
+    done
+done
+
+mkdir -p "$DESTINATION"
+for file in "$TEMP_DIR"/*.whl; do
+    unzip -o "$file" -d "$DESTINATION";
+done
+rm -rf "$TEMP_DIR"
+
+echo "Download complete"