Containerising MuleSoft's Blackbox Automated Testing (BAT) CLI tool
In this post we will assume that you have Docker and would like to create an image that contains the Blackbox Automated testing (BAT) application published by Mulesoft.
If you're looking for a Mule Docker image you can use without making your own, then you can check out mikeyryan/mule-blackbox-automated-testing on Docker Hub.
What is BAT?
The BAT CLI is an API Functional Monitoring tool produced by MuleSoft for assuring the quality and reliablility of APIs. It provides a convenient method for those working in the MuleSoft technology stack to implement Black-box testing and Runtime monitoring. Using dataweave, it is possible to develop tests that validate the behavior of APIs against live upstream systems, based on inputs and outputs. Additionally, it has a monitoring capability that allows you to verify that deployed APIs are operating as expected and output test results in a variety of formats as a once off operation or on a schedule.
Why Containerise BAT?
BAT will run perfectly fine anywhere that you can install Java. However, you may find yourself in need of a solution that's more scalable than installing it on a standalone machine or needing to run multiple versions it at the same time. In fact, a typical scenario for using BAT is as part of a Continuous Integration (CI) and Continuous Deployment (CD) process to test your API before pushing code into a shared repository and/or verifying that a deployment to production has worked correctly. With Docker we can easily package BAT in a container which is useful for portability, as Docker will help ue sneusre that our tests will run the same locally as they will when deployed to a server or used as part of a CI/CD process.
Creating a Docker image
To begin with, we will need to create file called Dockerfile in our working directory. A Dockerfile has a file format that contains instructions and arguments, which define the contents and startup behaviour of the Docker container. To run BAT, our Dockerfile will need to contain the following:
# The first instruction in a Dockerfile must be FROM, which selects a base image. Since it's recommended to use official Docker images, we will use the official image for maven.
FROM maven:3.6-jdk-8
LABEL maintainer="https://mike.gough.me"
# Install BAT using the script provided by MuleSoft
RUN curl -o- 'https://s3.amazonaws.com/bat-wrapper/install.sh' | bash
# Set the workdir to the default for the maven image we are using
WORKDIR /usr/src/mymaven
# Start BAT when the container is run
ENTRYPOINT ["bash", "bat"]
The above Docker file will create an image based on the official maven Docker image. It downloads and installs the latest version of BAT. To create the Docker image with the latest version of BAT, run the following command:
docker build mule-blackbox-automated-testing:latest .
Thats it! In a future post we will look at how we can use our BAT container to test an API.