Run Google Lighthouse in Docker Container

Thanks to my Colleague Simon’s suggestion, I was introduced to Google Lighthouse, an opensource nodejs framework to use Google Chrome to audit a website’s performance.

I like Lighthouse because:

  • opensource
  • good portability
  • can run as CLI command or as a nodejs module

Here’s a sample Dockerfile to have a container ready to run Lighthouse with Google Chrome for Linux.

FROM debian:stretch

USER root
ENV CHROME_VERSION="google-chrome-stable"

# system packages
RUN apt update -qqy && \
  apt install -qqy build-essential gnupg wget curl jq

# nodejs 10
RUN curl -sL | bash - && \
  apt install -qqy nodejs && \
  npm install -g lighthouse

# google-chrome
RUN wget -q -O - | apt-key add - && \
  echo "deb stable main" >> /etc/apt/sources.list.d/google-chrome.list && \
  apt update -qqy && \
  apt install -qqy ${CHROME_VERSION:-google-chrome-stable}

# python3 (optional for metric processing)
RUN apt install -qqy python3 python3-pip && \
  pip3 install influxdb

# lighthouse
RUN useradd -ms /bin/bash lighthouse
USER lighthouse
WORKDIR /home/lighthouse

Then lighthouse can be executed in the container to audit $url:

CHROME_PATH=$(which google-chrome) lighthouse $url --emulated-form-factor=none --output=json --chrome-flags="--headless --no-sandbox"

The result json will be sent to stdout, and it can be easily piped to other scripts for post processing, eg. parse json and extract metrics, etc…