• Overview
  • Highlights
• Workflow
• System requirements
  • ITRS OP5 Monitor example
• Docker image
• Plugin
• Add new test scenarios
• Execute the plugin
• License

Synthetic website monitoring with Selenium and Docker.

check_selenium_docker is a Nagios based plugin that spins up a Docker container, executes the test and, once the test is finished and the result has been reported back to the monitoring solution, removes the Docker container.

• Works with any Nagios compatible system such as ITRS OP5 Monitor, Icinga2 or Nagios.
• Every test is executed in a fresh environment. (https://www.selenium.dev/documentation/en/guidelines_and_recommendations/fresh_browser_per_test/)
• Will remove the Docker container as soon as the test is complete. Requires no manual cleanup of stopped containers.

Install Selenium IDE for Chrome (https://selenium.dev/downloads).

Record your test.

Export the test and copy the .side file to the server that will run the docker image.

A Docker container will execute the test and report the test results back to the monitoring system.

The following prerequisites must be installed on the server that will execute the plugin.

• Python 3 with the docker module
• docker-ce

# Install docker-ce
yum install -y yum-utils \
  device-mapper-persistent-data \
  lvm2

yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo

yum install docker-ce

# Add user 'monitor' to group 'docker'
usermod -aG docker monitor

# Start and enable docker
systemctl start docker && systemctl enable docker

# Install the docker Python 3 module
pip-3 install docker

# (Optional) Add versionlock to docker-ce
yum install yum-plugin-versionlock
yum versionlock docker-ce

# (Optional) Remove versionlock from docker-ce
yum versionlock clear

Build the Docker image:

git clone https://github.com/opsdis/check_selenium_docker
cd check_selenium_docker/dockerimage/
docker build . --tag opsdis/selenium-chrome-node-with-side-runner

Copy the plugin to the plugin directory and make it executable:

cp check_selenium_docker.py /opt/plugins/custom/
chmod +x /opt/plugins/custom/check_selenium_docker.py

Add a new check_command to Monitor:

check_selenium_docker
$USER1$/custom/check_selenium_docker.py $ARG1$

Create a new main directory (/opt/plugins/custom/selenium) in the main directory create a new directory preferably named as the URL used in the test (/opt/plugins/custom/selenium/opsdis.com):

mkdir /opt/plugins/custom/selenium
mkdir /opt/plugins/custom/selenium/opsdis.com

Create two subdirectories, out and sides:

mkdir /opt/plugins/custom/selenium/opsdis.com/{out,sides}

Add the side-file to the sides subdirectory and modify the permissions:

chmod 777 /opt/plugins/custom/selenium/opsdis.com/out/
chmod 755 /opt/plugins/custom/selenium/opsdis.com/sides/opsdis.com.side

The directory structure should look like this:

├── opsdis.com
│   ├── out
│   └── sides
│       └── opsdis.com.side

/opt/plugins/custom/check_selenium_docker.py /opt/plugins/custom/selenium/opsdis.com
OK: Passed 1 of 1 tests. | 'passed'=1;;;; 'failed'=0;;;; 'exec_time'=6s;;;;

check_selenium_docker is licensed under GPL version 3.