Docker for QA

Here's a step-by-step guide to getting started with Docker

To get started with a sample setup using Tomcat, PostgreSQL, and CentOS 9, you'll need to follow these steps:

Step 1: Install Docker

Ensure Docker is installed and running on your laptop.

Step 2: Pull CentOS 9 Image

Open a terminal and pull the CentOS 9 Docker image: docker pull centos:9

Step 3: Run a CentOS 9 Container

Create and start a CentOS 9 container: docker run -it --name my-centos9 centos:9

Step 4: Install Java 18

Inside the CentOS container, install Java 18. You can either download the JDK manually or use tools like yum or dnf if they're available in the CentOS 9 repository.

Step 5: Install Tomcat

Similarly, install Tomcat within the container. Download the Tomcat package and configure it according to your requirements.

Step 6: Install PostgreSQL

• Still within the container, install PostgreSQL: yum install postgresql-server postgresql-contrib

• Initialize the database: postgresql-setup initdb

• Start PostgreSQL service: systemctl start postgresql

Step 7: Set Up and Run the Java Sample Application

Create and deploy your Java sample application (WAR file) to the Tomcat server within the container. Ensure it's properly configured to connect to the PostgreSQL database.

Step 8: Expose Container Ports

To access Tomcat and PostgreSQL from your laptop, map container ports to your local machine. 

Stop the running container: docker stop my-centos9

Then start it again, mapping ports: docker run -it --name my-centos9 -p 8080:8080 -p 5432:5432 centos:9

Step 9: Access Services

• Tomcat: Open a web browser and go to http://localhost:8080 to access your Tomcat server.

• PostgreSQL: Use your preferred database client to connect to localhost on port 5432 (default PostgreSQL port).

Similary, you can also try installing Selenium Webdriver using Docker

Dockerfile for creating an image with Ubuntu, Java, Selenium, and Chrome

Building the Docker image:

1. Save the modified Dockerfile in a directory.

2. Open a terminal, navigate to the directory containing the Dockerfile.

3. Run the following command to build the Docker image: docker build -t ubuntu_selenium_java .

Running a container using the pulled image:

After the image is built, you can start a container based on that image: docker run -it ubuntu_selenium_java