Found 48 Articles for Virtual Machines

Introduction Using variables in a Dockerfile CMD can greatly improve the flexibility and maintainability of container configuration. Hardcoding values in a CMD instruction can make it difficult to update or modify the container's configuration in the future. Using variables allows for more dynamic and reusable configurations. Prerequisites The prerequisites for using variables inside a Dockerfile CMD depend on the method you choose to use − Using shell expansion − No specific prerequisites are required. Using the ENV instruction − No specific prerequisites are required. Using the ARG instruction − No specific prerequisites are required. Passing variable at runtime − ... Read More

Introduction When working with Docker on Windows, it is possible to use network drives as volumes. This allows you to store data on a network drive and access it from within a Docker container. This can be useful in situations where you need to share data between containers, or between the host and the container. With network drive as volume, you can easily store, manage and backup your data in a centralized location and use it with multiple Docker containers. In this article, we will explore the process of adding network drives as volumes in Docker on Windows, and the ... Read More

Introduction Docker is a popular containerization platform that allows users to package and deploy applications in a standardized and isolated environment. Docker uses a file called a Dockerfile to specify the instructions for building and running a Docker container. One important element of a Dockerfile is the VOLUME instruction, which specifies a mount point for a volume in the container. In this article, we will explore the purpose and usage of volumes in a Dockerfile. Definition of volume in Dockerfile In the context of Docker, a volume is a persistent storage location that exists outside of the container. Volumes ... Read More

Introduction The Docker daemon is a background process that manages Docker containers and is responsible for the creation, execution, and deletion of containers. One key component of the Docker daemon is the Docker daemon socket, which is used to communicate with the daemon from the Docker CLI and other applications. It is important to secure the Docker daemon socket to prevent unauthorized access to the Docker daemon and to protect sensitive information that may be exposed through the socket. In this article, we will discuss the location and default permissions of the Docker daemon socket, potential security risks, and best ... Read More

Introduction Splash is a powerful tool for rendering JavaScript-based websites, making it an essential tool for web scraping and data extraction. In this tutorial, we will show you how to run Splash using Docker Toolbox, an older version of Docker that is no longer being maintained but is still available for download. Prerequisites Before you can get started, you will need to install Docker Toolbox on your machine. Docker Toolbox is a version of Docker that is designed to run on older systems and/or systems without native virtualization. It is available for Windows, macOS, and Linux. Follow the steps ... Read More

Introduction Embedded Docker resource files are files included in a Docker image rather than stored on the host file system or an external network location. These files can be useful for including configuration files, scripts, or other resources that are needed by the applications or processes running in the Docker container. You can reference embedded Docker resource files in several different ways, including using file path URLs. This article explains what file path URLs are and how to use them to reference embedded Docker resource files. We will also provide tips and examples to help you use file path URLs ... Read More

Introduction In a Docker Tomcat 8 container, you may want to change the user configuration to add or modify users and roles. This modification can be useful for tasks like securing access to the Tomcat 8 instance or setting up different levels of permissions for different users. This article explains how to change the user configuration in a Docker Tomcat 8 container. We cover the steps involved in modifying the tomcat-users.xml file, building a new Docker image with the modified configuration, and running a Docker container from the new image. Prerequisites Before changing the user configuration in a Docker Tomcat ... Read More

JMX and its use in Java applications JMX (Java Management Extensions) is a Java technology that provides a way to manage and monitor Java applications. It exposes a set of APIs and MBeans (Java objects that represent resources to be managed) that can be used to monitor and control the behaviour of a Java application. JMX is commonly used in Java-based applications to monitor performance metrics such as memory usage, CPU utilization, and thread counts, as well as to manage and configure the application at runtime. Accessing JMX from outside a Docker container When running a Java application in a ... Read More

Overview If you are using Docker Compose to define and run multi-container Docker applications, you may want to specify custom configuration files or directories for your application. Fortunately, Docker Compose provides the --config option, which allows you to do just that. The --config option is used to specify a single configuration file or a directory containing multiple configuration files for Docker Compose. To use it, you can pass it as an argument to the docker-compose command. For example − $ docker-compose --config /path/to/custom/config.yml up This command would tell Docker Compose to use the configuration file located at /path/to/custom/config.yml ... Read More

Introduction Vagrant is a tool for building and managing development environments using virtualization software such as VirtualBox. It allows you to define and configure a development environment in a Vagrantfile and then spin up and tear down virtual machines quickly and easily. By using Docker and Vagrant together, you can create a flexible and reproducible development environment that is easy to set up and maintain. This article discusses the best way to install Docker on Vagrant, including the prerequisites, installation steps, and verification. Prerequisites for installing Docker on Vagrant Before installing Docker on Vagrant, you must ensure you have the ... Read More