add build-and-run.sh to python relay server

package-testing/python-sdk-relay/README.md

@@ -2,6 +2,12 @@
 
 Post test case files to this server and check the results against what's expected.
 
+## Build and run
+
+```shell
+./build-and-run.sh
+```
+
 ## Running locally with Docker
 
 Build the docker image:

package-testing/python-sdk-relay/build-and-run.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+
+# Set default values for vars
+
+: "${SDK_REF:=main}"
+: "${SDK_RELAY_HOST:=localhost}"
+: "${SDK_RELAY_PORT:=4000}"
+SDK="https://github.com/Eppo-exp/eppo-multiplatform.git"
+
+# checkout the specified ref of the SDK repo, build it, and then insert it into vendors here.
+rm -rf tmp
+mkdir -p tmp
+
+echo "Cloning ${SDK}@${SDK_REF}"
+git clone -b ${SDK_REF} --depth 1 --single-branch ${SDK} tmp || ( echo "Cloning repo failed"; exit 1 )
+
+# Run the poller
+python3 -m venv tmp/.venv
+source tmp/.venv/bin/activate
+pip install maturin
+
+# Build the wheel file in tmp directory
+maturin build --release --out tmp/dist --find-interpreter --manifest-path ./tmp/python-sdk/Cargo.toml
+
+# Get Python version and find matching wheel
+PYTHON_VERSION=$(python3 -c 'import sys; print(f"cp{sys.version_info.major}{sys.version_info.minor}")')
+echo "Looking for wheel for Python version: ${PYTHON_VERSION}"
+
+WHEEL_FILE=$(find tmp/dist -name "eppo_server_sdk-*-${PYTHON_VERSION}-*.whl" | head -n 1)
+echo "Found wheel file: ${WHEEL_FILE}"
+
+if [ -z "$WHEEL_FILE" ]; then
+    echo "Error: Wheel file not found for Python version ${PYTHON_VERSION}"
+    echo "Available wheels:"
+    ls tmp/dist
+    exit 1
+fi
+
+pip install "${WHEEL_FILE}"
+
+echo "Listening on port ${SDK_RELAY_PORT}"
+
+python3 -m http.server ${SDK_RELAY_PORT}