{"id":6574,"date":"2017-08-18T02:25:19","date_gmt":"2017-08-18T06:25:19","guid":{"rendered":"https:\/\/qxf2.com\/blog\/?p=6574"},"modified":"2019-01-24T08:24:13","modified_gmt":"2019-01-24T13:24:13","slug":"preparing-a-docker-image-for-running-selenium-tests","status":"publish","type":"post","link":"https:\/\/qxf2.com\/blog\/preparing-a-docker-image-for-running-selenium-tests\/","title":{"rendered":"Preparing a Docker image for running Selenium tests"},"content":{"rendered":"

Sometimes your team members complain about automated tests not working on their computer while you are able to run the automated tests at your end completely fine. We too, at Qxf2<\/a>, have experienced this issue. Our automated tests run fine at our end but occasionally fail when they run on our colleagues and client machines. Invariably, we trace this sort of failure down to variations in the setup\/environment. So we looked to tackle this issue. We decided to build a Docker<\/a> container for running our Selenium tests. The process was very quick and we decided to help all our fellow testers by sharing how we went about doing it.<\/p>\n

This post assumes you already know a little about Docker. <\/p>\n

NOTE:<\/strong> If you are just looking for a Docker image, you can skip ‘Step 1. Creating a Dockerfile’ section and directly move on to the step 2 titled as ‘Build\/Pull the Docker image’. <\/p>\n

\n

Overview:<\/h3>\n

We will be performing the following steps:
\n1. Creating a Dockerfile
\n2. Build\/Pull the Docker image
\n3. Creating a container and running Selenium tests<\/p>\n

\n

Step 1. Creating a Dockerfile for running Selenium tests:<\/h3>\n

To get setup with Docker CE you can refer to this link<\/a>. To build a Docker image for running our Selenium tests, we needed to perform the following steps:<\/p>\n

    \n
  1. Pull a Base image<\/li>\n
  2. Install Xvfb virtual\/headless display<\/li>\n
  3. Setup Chrome and Chrome driver<\/li>\n
  4. Setup Firefox and Geckodrivers<\/li>\n
  5. Install Python 2.7 and Python Pip<\/li>\n
  6. Get your project code into image\/container and install requirements with help of pip and project requirements.txt file<\/li>\n<\/ol>\n

    All the steps except the final one rarely change unless when we decide to change the version of software installed. However, your project code and requirements change frequently. So, we decided to come up with a base image for Selenium which includes the first 5 steps i.e Ubuntu, Chrome with Chrome driver, Firefox with Geckodriver, Xvfb, Python and Python\u00a0Pip. <\/p>\n

    We will code these steps into a file called a Dockerfile. A Dockerfile<\/a> is a text document that contains all the commands a user could execute on the command line to assemble an image. To build the base image for running the Selenium test, we wrote the following Dockerfile.<\/p>\n

    1. Pull a Base Image<\/strong>
    \nWe used Ubuntu 16.04. <\/p>\n

    \r\n#Contents of Dockerfile\r\n#Dockerfile to build an image which supports testing our Qxf2 Page Object Model.\r\nFROM ubuntu\r\nMAINTAINER Qxf2 Services\r\n<\/pre>\n
    2. Install Xvfb virtual\/headless display<\/strong><\/p>\n
    \r\n# Essential tools and xvfb\r\nRUN apt-get update && apt-get install -y \\\r\n    software-properties-common \\\r\n    unzip \\\r\n    curl \\\r\n    xvfb \r\n<\/pre>\n
    3. Setup Chrome and Chrome driver<\/strong><\/p>\n
    \r\n# Chrome browser to run the tests\r\nRUN curl https:\/\/dl-ssl.google.com\/linux\/linux_signing_key.pub -o \/tmp\/google.pub \\\r\n    && cat \/tmp\/google.pub | apt-key add -; rm \/tmp\/google.pub \\\r\n    && echo 'deb http:\/\/dl.google.com\/linux\/chrome\/deb\/ stable main' > \/etc\/apt\/sources.list.d\/google.list \\\r\n    && mkdir -p \/usr\/share\/desktop-directories \\\r\n    && apt-get -y update && apt-get install -y google-chrome-stable\r\n# Disable the SUID sandbox so that chrome can launch without being in a privileged container\r\nRUN dpkg-divert --add --rename --divert \/opt\/google\/chrome\/google-chrome.real \/opt\/google\/chrome\/google-chrome \\\r\n    && echo \"#!\/bin\/bash\\nexec \/opt\/google\/chrome\/google-chrome.real --no-sandbox --disable-setuid-sandbox \\\"\\$@\\\"\" > \/opt\/google\/chrome\/google-chrome \\\r\n    && chmod 755 \/opt\/google\/chrome\/google-chrome\r\n\r\n# Chrome Driver\r\nRUN mkdir -p \/opt\/selenium \\\r\n    && curl http:\/\/chromedriver.storage.googleapis.com\/2.45\/chromedriver_linux64.zip -o \/opt\/selenium\/chromedriver_linux64.zip \\\r\n    && cd \/opt\/selenium; unzip \/opt\/selenium\/chromedriver_linux64.zip; rm -rf chromedriver_linux64.zip; ln -fs \/opt\/selenium\/chromedriver \/usr\/local\/bin\/chromedriver;\r\n<\/pre>\n
    4. Setup Firefox and Geckodrivers<\/strong><\/p>\n
    \r\n# Firefox browser to run the tests\r\nRUN apt-get install -y firefox\r\n\r\n# Gecko Driver\r\nENV GECKODRIVER_VERSION 0.23.0\r\nRUN wget --no-verbose -O \/tmp\/geckodriver.tar.gz https:\/\/github.com\/mozilla\/geckodriver\/releases\/download\/v$GECKODRIVER_VERSION\/geckodriver-v$GECKODRIVER_VERSION-linux64.tar.gz \\\r\n  && rm -rf \/opt\/geckodriver \\\r\n  && tar -C \/opt -zxf \/tmp\/geckodriver.tar.gz \\\r\n  && rm \/tmp\/geckodriver.tar.gz \\\r\n  && mv \/opt\/geckodriver \/opt\/geckodriver-$GECKODRIVER_VERSION \\\r\n  && chmod 755 \/opt\/geckodriver-$GECKODRIVER_VERSION \\\r\n  && ln -fs \/opt\/geckodriver-$GECKODRIVER_VERSION \/usr\/bin\/geckodriver \\\r\n  && ln -fs \/opt\/geckodriver-$GECKODRIVER_VERSION \/usr\/bin\/wires\r\n<\/pre>\n
    Note:<\/strong> Please make sure you update the script to download the latest ChromeDriver<\/a> and geckodriver<\/a> versions<\/p>\n
    5. Install Python 2.7 and Python Pip<\/strong><\/p>\n
    \r\n# python\r\nRUN apt-get update && apt-get install -y \\\r\n    python \\\r\n    python-setuptools \\\r\n    python-pip\r\n<\/pre>\n
    Putting it all together<\/strong>
    \nOur final Dockerfile looks like this:<\/p>\n
    #Contents of Dockerfile\r\n#Dockerfile to build an image which supports testing our Qxf2 Page Object Model.\r\nFROM ubuntu\r\nMAINTAINER Qxf2 Services\r\n\r\n# Essential tools and xvfb\r\nRUN apt-get update && apt-get install -y \\\r\n    software-properties-common \\\r\n    unzip \\\r\n    curl \\\r\n    xvfb \r\n\r\n# Chrome browser to run the tests\r\nRUN curl https:\/\/dl-ssl.google.com\/linux\/linux_signing_key.pub -o \/tmp\/google.pub \\\r\n    && cat \/tmp\/google.pub | apt-key add -; rm \/tmp\/google.pub \\\r\n    && echo 'deb http:\/\/dl.google.com\/linux\/chrome\/deb\/ stable main' > \/etc\/apt\/sources.list.d\/google.list \\\r\n    && mkdir -p \/usr\/share\/desktop-directories \\\r\n    && apt-get -y update && apt-get install -y google-chrome-stable\r\n# Disable the SUID sandbox so that chrome can launch without being in a privileged container\r\nRUN dpkg-divert --add --rename --divert \/opt\/google\/chrome\/google-chrome.real \/opt\/google\/chrome\/google-chrome \\\r\n    && echo \"#!\/bin\/bash\\nexec \/opt\/google\/chrome\/google-chrome.real --no-sandbox --disable-setuid-sandbox \\\"\\$@\\\"\" > \/opt\/google\/chrome\/google-chrome \\\r\n    && chmod 755 \/opt\/google\/chrome\/google-chrome\r\n\r\n# Chrome Driver\r\nRUN mkdir -p \/opt\/selenium \\\r\n    && curl http:\/\/chromedriver.storage.googleapis.com\/2.45\/chromedriver_linux64.zip -o \/opt\/selenium\/chromedriver_linux64.zip \\\r\n    && cd \/opt\/selenium; unzip \/opt\/selenium\/chromedriver_linux64.zip; rm -rf chromedriver_linux64.zip; ln -fs \/opt\/selenium\/chromedriver \/usr\/local\/bin\/chromedriver;\r\n\r\n# Firefox browser to run the tests\r\nRUN apt-get install -y firefox\r\n\r\n# Gecko Driver\r\nENV GECKODRIVER_VERSION 0.23.0\r\nRUN wget --no-verbose -O \/tmp\/geckodriver.tar.gz https:\/\/github.com\/mozilla\/geckodriver\/releases\/download\/v$GECKODRIVER_VERSION\/geckodriver-v$GECKODRIVER_VERSION-linux64.tar.gz \\\r\n  && rm -rf \/opt\/geckodriver \\\r\n  && tar -C \/opt -zxf \/tmp\/geckodriver.tar.gz \\\r\n  && rm \/tmp\/geckodriver.tar.gz \\\r\n  && mv \/opt\/geckodriver \/opt\/geckodriver-$GECKODRIVER_VERSION \\\r\n  && chmod 755 \/opt\/geckodriver-$GECKODRIVER_VERSION \\\r\n  && ln -fs \/opt\/geckodriver-$GECKODRIVER_VERSION \/usr\/bin\/geckodriver \\\r\n  && ln -fs \/opt\/geckodriver-$GECKODRIVER_VERSION \/usr\/bin\/wires\r\n\r\n# python\r\nRUN apt-get update && apt-get install -y \\\r\n    python \\\r\n    python-setuptools \\\r\n    python-pip\r\n<\/pre>\n
    \n
    Step 2. Build\/Pull the Docker image:<\/h3>\n
    You can either build your own image using above Dockerfile or you can directly download the image from our Docker Hub repository.<\/p>\n
    To build the image using above dockerfile,\u00a0you need to save dockerfile to any directory in your system and use the following command:<\/p>\n
    docker build -t image_name path\/to\/dockerfile<\/pre>\n
    To directly download it from our Docker Hub repository<\/a>,\u00a0you need to use the following command:<\/p>\n
    docker pull qxf2rohand\/qxf2_pom_essentials<\/pre>\n
    \n
    Step 3. Creating a container and running Selenium tests:<\/h3>\n
    We decided to use this image for testing our Qxf2’s open sourced GUI automation framework<\/a>. We named the image as qxf2_pom_essentials. qxf2_pom_essentials image is capable of running any Python based Selenium tests. To run the Selenium tests using this image, you need to go through following steps:<\/p>\n
      \n
    1. Create a Docker container out of this image and enter into the container using the following command:\n
      docker run -it qxf2rohand\/qxf2_pom_essentials \"\/bin\/bash\"<\/pre>\n<\/li>\n
    2. Export display and enable Xvfb using following 2\u00a0commands:\n
      export DISPLAY=:20\r\nXvfb :20 -screen 0 1366x768x16 &<\/pre>\n<\/li>\n
    3. Install Selenium using pip\n
      pip install selenium<\/pre>\n<\/li>\n
    4. Use any Linux editor you like and add your test inside the container. You can also use the sample Selenium code (selenium_docker.py) given below. This selenium test visits Qxf2 Services website and prints the title.\n
      # contents of selenium_docker.py\r\nfrom selenium import webdriver\r\n\r\ndriver = webdriver.Firefox()\r\ndriver.get(\"http:\/\/www.qxf2.com\")\r\nprint driver.title\r\ndriver.quit()<\/pre>\n<\/li>\n
    5. Run the selenium test using the following command:\n
      python selenium_docker.py<\/pre>\n
      The output will be similar to the screenshot shown below.
      \n
      \"\"<\/a>
      Fig. 1 Output of selenium_docker.py<\/figcaption><\/figure><\/li>\n<\/ol>\n
      Note:<\/strong> The above steps are only to show you how to use our Docker image. At Qxf2 Services, for testing our Qxf2’s Public Page Object Model<\/a> we use another Dockerfile which automatically gets our code from GitHub, setup our requirements, run shell script file to enable Xvfb and run the test. <\/p>\n
      \n
      To know more about how to get your code inside the container and run the test, please stay tuned. We will post about it soon. Until then enjoy running your tests anywhere without thinking about environment set up using this Docker image. Happy testing!<\/p>\n
      If you are a startup finding it hard to hire technical QA engineers, learn more about Qxf2 Services<\/a>.<\/strong><\/p>\n<\/hr>\n