fetch-pinned-chrome.sh

#!/bin/bash
#
# Fetch a pinned Chrome for Testing + matching chromedriver into client/chrome/.
#
# Why pin: the experiment measures latency through a browser, so the browser is part of the
# apparatus and must not drift. Concretely, Chrome 149 refuses the SDP answer produced by
# mediasoup 3.14.15 -
#   "Failed to set remote answer sdp: RTP extension ID reassignment not supported"
# - so publishing fails outright on a current system Chrome. 130.0.6723.116 is the version
# the thesis ran on and works.
#
# Writes the resolved paths into client/config.json so the harness uses them.

set -euo pipefail

CHROME_VERSION="${CHROME_VERSION:-130.0.6723.116}"
PLATFORM="${PLATFORM:-linux64}"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
DEST="$SCRIPT_DIR/client/chrome/$CHROME_VERSION"
BASE="https://storage.googleapis.com/chrome-for-testing-public/$CHROME_VERSION/$PLATFORM"

usage() { echo "Usage: $0 [--version X.Y.Z.W] [--no-config]"; exit 0; }
WRITE_CONFIG=1
while [[ $# -gt 0 ]]; do
    case $1 in
        --version) CHROME_VERSION="$2"; DEST="$SCRIPT_DIR/client/chrome/$CHROME_VERSION"; BASE="https://storage.googleapis.com/chrome-for-testing-public/$CHROME_VERSION/$PLATFORM"; shift ;;
        --no-config) WRITE_CONFIG=0 ;;
        -h|--help) usage ;;
        *) echo "Unknown parameter: $1"; usage ;;
    esac
    shift
done

CHROME_BIN="$DEST/chrome-$PLATFORM/chrome"
DRIVER_BIN="$DEST/chromedriver-$PLATFORM/chromedriver"

if [ ! -x "$CHROME_BIN" ] || [ ! -x "$DRIVER_BIN" ]; then
    mkdir -p "$DEST"
    echo "Fetching Chrome for Testing $CHROME_VERSION ($PLATFORM) into $DEST"
    for artefact in chrome chromedriver; do
        url="$BASE/$artefact-$PLATFORM.zip"
        if ! curl -fsSL -o "$DEST/$artefact.zip" "$url"; then
            echo "Failed to download $url"
            echo "Check the version exists: https://googlechromelabs.github.io/chrome-for-testing/"
            exit 1
        fi
        unzip -q -o "$DEST/$artefact.zip" -d "$DEST"
        rm -f "$DEST/$artefact.zip"
    done
    chmod +x "$CHROME_BIN" "$DRIVER_BIN"
else
    echo "Already present at $DEST"
fi

echo "chrome:       $("$CHROME_BIN" --version)"
echo "chromedriver: $("$DRIVER_BIN" --version | head -1)"

if [ "$WRITE_CONFIG" = "1" ]; then
    CONFIG="$SCRIPT_DIR/client/config.json"
    jq --arg b "$CHROME_BIN" --arg d "$DRIVER_BIN" \
       '.chrome = {binaryPath: $b, driverPath: $d}' "$CONFIG" > "$CONFIG.tmp" && mv "$CONFIG.tmp" "$CONFIG"
    echo "Wrote both paths into client/config.json"
fi