I have been writing a lot of tests lately with Cypress, and one thing that I noticed when running over night using a scheduled task is that they really slow down the whole server performance as it's taking huge amount of CPU and RAM.

Kind of expected as Cypress is running Electron.

I don't like having a single application crippling the server, so:

Why not "dockerize" the tests, and run on a powerful VPS and only pay the for time it needs to be run?

As of now my tests are running on a Windows server and upgrading the instance size wouldn't be cost effective, as I need that much CPU/RAM only for couple of hours per day.

Increase test performance while decreasing costs

We can achieve it following this steps:

Spin a powerful Linux VPS on the cloud (AWS, Azure, Google, Linode etc)
Install docker
Run the cypress tests inside the docker container
Delete the VPS we just created

Of course the above would be automated with some sort of script that start on a given time every day.

Create the project inside the new VPS


# Create the project folder and cd into it

mkdir myproject && cd myproject

# Create an empty dockerfile

touch dockerfile

# Copy is_rsa from your local pc to the VPS or create a new one, this is needed to clone the repo later using ssh

# Copy your local openvpn file or create one. Ex: my-vpn-config.ovpn

Your folder structure should look like this:

#### myproject
   # dockerfile
   # id_rsa
   # my-vpn-config.ovpn

Dockerfile

The dockerfile in my case needed to accomplish this tasks:

Install required packages
Install Chrome
Create folders and set permissions
Run openvpn
Update HOST file
Clone a repository using ssh
Run tests

It's my first time messing with a dockerfile, I know that using root is not the best practice but this is just an example on how to achieve running tests on a docker container, use it just as an inspiration to forge your own dockerfile

nano dockerfile

# Using ubuntu base image
FROM ubuntu:latest

# Package install explanation:
# openvpn: OpenVPN client
# iputils-ping: ping command
# openssh-client: ssh command
# apt-utils: apt-get command
# curl: curl command
# gcc: gcc command, node dependency
# g++: g++ command, node dependency
# make: make command, node dependency
# libgtk2.0-0: Cypress dependency
# libgtk-3-0: Cypress dependency
# libgbm-dev: Cypress dependency
# libnotify-dev: Cypress dependency
# libgconf-2-4: Cypress dependency
# libnss3: Cypress dependency
# libxss1: Cypress dependency
# libasound2: Cypress dependency
# libxtst6: Cypress dependency
# xauth: Cypress dependency
# xvfb: Cypress dependency
# wget: wget command, chrome
# gnupg: gnupg command, chrome
# ca-certificates: ca-certificates command, chrome
# x11-utils: x11-utils command, chrome
# git: git command, clone repo
# nodejs: nodejs command, run cypress tests

RUN apt-get update && \
    apt-get install -y openvpn \
    iputils-ping \
    openssh-client \
    apt-utils \
    curl \
    gcc \
    g++ \
    make \
    libgtk2.0-0 \
    libgtk-3-0 \
    libgbm-dev \
    libnotify-dev \
    libgconf-2-4 \
    libnss3 \
    libxss1 \
    libasound2 \
    libxtst6 \
    xauth \
    xvfb \
    wget \
    gnupg \
    ca-certificates \
    x11-utils \
    git && \
    curl -sL https://deb.nodesource.com/setup_16.x | bash - && \
    apt-get install -y nodejs

# Get Google chrome and install

RUN wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | apt-key add - && \
    echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google-chrome.list && \
    apt-get update && \
    apt-get install -y google-chrome-stable

ENV DISPLAY=:99

# Copy the OpenVPN configuration file and the GitLab SSH key to the container

COPY my-vpn-config.ovpn /etc/openvpn/

COPY id_rsa /root/.ssh/id_rsa

# Set the permissions for the SSH key

RUN chmod 400 /root/.ssh/id_rsa

# Set the environment variables for the OpenVPN connection

ENV VPN_USERNAME=vpnUsernameHere

ENV VPN_PASSWORD=vpnPasswordHere

# Create a script to start the OpenVPN connection and run the Cypress tests

# cypress.env.json is base 64 encoded then decoded in the Dockerfile

RUN echo '#!/bin/bash\n\
openvpn --config /etc/openvpn/my-vpn-config.ovpn --auth-user-pass <(echo -e "$VPN_USERNAME\n$VPN_PASSWORD") &\n\
while ! ping -c1 -W 1 8.8.8.8; do sleep 1; done\n\
sleep 10\n\
ssh-keyscan myCompany.com >> /root/.ssh/known_hosts\n\
git clone --branch dev_sql [email protected]:user/cypress-automation.git\n\
cd cypress-automation\n\
mkdir ./cypress/logs/\n\
npm install\n\
npm run sd:test\n' > /root/start.sh

# Set the permissions for the script

RUN chmod +x /root/start.sh

# Expose the Cypress test results

VOLUME /root/myproject/cypress/results

# Start the Xvfb server and run the script

CMD /bin/bash -c "Xvfb $DISPLAY -screen 0 1024x768x16 -ac & /root/start.sh"

Build the image

docker build -t cypress-tests .

Run the container

docker run -p 8080:443  --add-host myCompany.com:192.100.23.222 --privileged --rm -it cypress-tests

Increase test performance while decreasing costs

Create the project inside the new VPS

Dockerfile

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