Dockerfile.sandbox-browser

# Sandbox browser container for OpenClaw's browser tool.
# Provides headless Google Chrome with CDP exposed via socat proxy.
#
# OpenClaw launches this container with:
#   --read-only --cap-drop ALL --security-opt no-new-privileges --user 0:0
# The only guaranteed writable path is /dev/shm (tmpfs), so we point all
# browser writable state there via /tmp and XDG dirs.

FROM debian:bookworm-slim

ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update \
  && apt-get install -y --no-install-recommends \
    ca-certificates \
    curl \
    gnupg \
    wget \
    socat \
    fonts-liberation \
    libnss3 \
    libatk-bridge2.0-0 \
    libgtk-3-0 \
    libgbm1 \
    libasound2 \
  && install -d -m 0755 /etc/apt/keyrings \
  && wget -qO- https://dl.google.com/linux/linux_signing_key.pub \
    | gpg --dearmor -o /etc/apt/keyrings/google-chrome.gpg \
  && echo "deb [arch=amd64 signed-by=/etc/apt/keyrings/google-chrome.gpg] https://dl.google.com/linux/chrome/deb/ stable main" \
    > /etc/apt/sources.list.d/google-chrome.list \
  && apt-get update \
  && apt-get install -y --no-install-recommends google-chrome-stable \
  && rm -rf /var/lib/apt/lists/*

# Redirect /tmp -> /dev/shm so that writes land on the always-writable tmpfs.
# OpenClaw mounts the container --read-only and suppresses VOLUME auto-creation,
# so /tmp is read-only at runtime.  /dev/shm is the only guaranteed writable path.
RUN rm -rf /tmp && ln -s /dev/shm /tmp

COPY --chmod=755 scripts/sandbox-browser-entrypoint.sh /usr/local/bin/sandbox-browser-entrypoint

ENV OPENCLAW_BROWSER_NO_SANDBOX=1

RUN useradd --create-home --shell /bin/bash sandbox
USER sandbox
WORKDIR /home/sandbox

CMD ["sandbox-browser-entrypoint"]