Introduction to Docker | What is Docker | Docker Containers

"This live session will help you to cover all the basic concepts of Docker. This session will start off with topics such as

• What is Docker?
• What are Containers?
• Why do we need Docker?
• Docker Engine, Docker Images, Docker Architecture.
  And then we will learn how to install docker and then finally we will run some basic Docker commands that are necessary to know when working with Docker.
  Once you are done learning all these concepts you will have an adequate idea about what Docker is and you can then move one to other more advanced Docker Concepts."

#docker #devops

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Ever Wondered Why We Use Containers In DevOps?

At some point we’ve all said the words, “But it works on my machine.” It usually happens during testing or when you’re trying to get a new project set up. Sometimes it happens when you pull down changes from an updated branch.

Every machine has different underlying states depending on the operating system, other installed programs, and permissions. Getting a project to run locally could take hours or even days because of weird system issues.

The worst part is that this can also happen in production. If the server is configured differently than what you’re running locally, your changes might not work as you expect and cause problems for users. There’s a way around all of these common issues using containers.

What is a container

A container is a piece of software that packages code and its dependencies so that the application can run in any computing environment. They basically create a little unit that you can put on any operating system and reliably and consistently run the application. You don’t have to worry about any of those underlying system issues creeping in later.

Although containers were already used in Linux for years, they became more popular in recent years. Most of the time when people are talking about containers, they’re referring to Docker containers. These containers are built from images that include all of the dependencies needed to run an application.

When you think of containers, virtual machines might also come to mind. They are very similar, but the big difference is that containers virtualize the operating system instead of the hardware. That’s what makes them so easy to run on all of the operating systems consistently.

What containers have to do with DevOps

Since we know how odd happenings occur when you move code from one computing environment to another, this is also a common issue with moving code to the different environments in our DevOps process. You don’t want to have to deal with system differences between staging and production. That would require more work than it should.

Once you have an artifact built, you should be able to use it in any environment from local to production. That’s the reason we use containers in DevOps. It’s also invaluable when you’re working with microservices. Docker containers used with something like Kubernetes will make it easier for you to handle larger systems with more moving pieces.

#devops #containers #containers-devops #devops-containers #devops-tools #devops-docker #docker #docker-image

Introduction to Docker Containers

Hello, readers! In this article, we will be focusing on the concept of Docker Containers, in detail. So, let us begin!

What are Virtual Machines [VM]?

Bare metal servers are inefficient. They require a lot of physical space, lots of cooling equipment, and impact the environment in a negative way. There had to be a better way out. The developers got thinking. Why not simply turn a single, powerful computer into a multi-dimensional server that runs multiple isolated applications simultaneously?

And this idea gave rise to the development of Virtual Machines.

Virtual Machines are computer files that are computer software that is an image and it acts like computer hardware. That is, it creates a computer within a computer. It virtualizes the environment for us. Above the VM, we have a hypervisor, also known as virtual machine monitor. This is software that creates, provisions, and runs Virtual machines over the actual physical hardware. It resides between the VM and the physical server and plays a key role in the virtualization of the server.

#docker #containers #docker containers

Docker Tutorial for Beginners 8 - Build and Run C++ Applications in a Docker Container

Docker is an open platform that allows use package, develop, run, and ship software applications in different environments using containers.
In this course We will learn How to Write Dockerfiles, Working with the Docker Toolbox, How to Work with the Docker Machine, How to Use Docker Compose to fire up multiple containers, How to Work with Docker Kinematic, Push images to Docker Hub, Pull images from a Docker Registery, Push stacks of servers to Docker Hub.
How to install Docker on Mac.

#docker tutorial #c++ #docker container #docker #docker hub #devopstools

Docker Explained: Docker Architecture | Docker Registries

Following the second video about Docker basics, in this video, I explain Docker architecture and explain the different building blocks of the docker engine; docker client, API, Docker Daemon. I also explain what a docker registry is and I finish the video with a demo explaining and illustrating how to use Docker hub

In this video lesson you will learn:

• What is Docker Host
• What is Docker Engine
• Learn about Docker Architecture
• Learn about Docker client and Docker Daemon
• Docker Hub and Registries
• Simple demo to understand using images from registries

#docker #docker hub #docker host #docker engine #docker architecture #api

Docker Swarm: Container Orchestration Using Docker Swarm

Introduction

A swarm consists of multiple Docker hosts that run in swarm mode and act as managers (to manage membership and delegation) and workers (which run swarm services). A given Docker host can be a manager, a worker, or perform both roles.

When Docker is running in swarm mode, you can still run standalone containers on any of the Docker hosts participating in the swarm, as well as swarm services. A key difference between standalone containers and swarm services is that only swarm managers can manage a swarm, while standalone containers can be started on any daemon.

In this demonstration, we will see how to configure the docker swarm and how to perform basic tasks.

Pre-requisites

1. For our demonstration, we will be using centos-07.
2. We will be using 3 machines for our lab, 1 machine as a swarm Manager node and 2 swarm worker nodes. These servers have below IP details:

192.168.33.76 managernode.unixlab.com

192.168.33.77 workernode1.unixlab.com

192.168.33.78 workernode2.unixlab.com

3. The memory should be at least 2 GB and there should be at least 2 core CPUs for each node.

#docker #containers #container-orchestration #docker-swarm