Docker

Editor's Notes

• #5: CONTAINERS Containers are an abstraction at the app layer that packages code and dependencies together. Multiple containers can run on the same machine and share the OS kernel with other containers, each running as isolated processes in user space. Containers take up less space than VMs (container images are typically tens of MBs in size), and start almost instantly. VIRTUAL MACHINES Virtual machines (VMs) are an abstraction of physical hardware turning one server into many servers. The hypervisor allows multiple VMs to run on a single machine. Each VM includes a full copy of an operating system, one or more apps, necessary binaries and libraries - taking up tens of GBs. VMs can also be slow to boot.
• #6: Docker (www.docker.com) isn't the world's only containerization platform, but it is the most popular. It is free, open-source, and Linux-based, with Windows support (Windows Server 2016) in the works. It has earned massive mindshare in the developer community. And with Azure Container Service, you can deploy Docker containers to Azure with minimal effort. Moreover, Docker containers are easily moved between Azure and Amazon Web Services (AWS), affording developers portability between cloud platforms. Docker containers wrap up a piece of software in a complete filesystem that contains everything it needs to run Code, runtime, system tools, system libraries – anything you can install on a server.
• #7: Docker utilizes a client-server architecture. You execute Docker commands through a Docker client such as the Docker CLI or Kitematic. The client uses REST commands to communicate with the Docker daemon running on a Docker host such as the Azure Container services. These commands can be used to push, pull (docker pull), and create Docker images, to run them in containers, and to manage those containers. Images can be built with the docker build command, and they can be stand-alone, or they can "inherit" from other images. Images are stored in Docker registries, which can be public or private, local or remote. Docker Hub is a popular public registry that is managed by Docker; it contains a "huge collection" of images that anyone may use. The docker run command runs a container using an image as a template.
• #8: The Docker Client, also known as the Docker CLI, is the primary tool you use to manage Docker containers. You can download container images from repositories such as Docker Hub, build container images, run container instances, list container images and instances, and much more. After connecting to Azure Container Service using SSH, you can use port forwarding to execute commands locally that act on an Azure Container Service running in the cloud. In this example, the -H switch used with the docker commands forwards commands sent to port 22375 on localhost to the Azure Container Services via SSH.
• #9: From the documentation: "Azure Container Service makes it simpler for you to create, configure, and manage a cluster of virtual machines that are preconfigured to run containerized applications. It uses an optimized configuration of popular open-source scheduling and orchestration tools. This enables you to use your existing skills, or draw upon a large and growing body of community expertise, to deploy and manage container-based applications on Microsoft Azure." ACS supports Linux containers and Windows containers. The latter rely on Windows Server 2016.
• #10: Orchestration in the context of containers is the deployment and management of containers across infrastructure and networks. It provides the tools and software defined infrastructure needed to deploy containers. Containers by design are intended to be deployed in large volumes with some applications using dozen to even thousands of containers. With this type of scale, automating deployment and management of containers with Orchestration Software becomes necessary.
• #11: A container cluster is intended to have redundancy for load balancing, scalability, and high availability. A cluster is composed of one or more Master Nodes which control the orchestration for scaling and delegation of tasks to the agents as well as provide monitoring. The Agent Nodes actually run the container loads.
• #12: Datacenter Operating System is, as the name implies, an operating system for for a datacenter rather than for a phyiscal of virtual machine. DC/OS abstracts away the underlying hardware from applications and provides much of the needed infrastructure that would otherwise come from multiple disparate services on traditional networks. This enables operations and developers alike to deploy and maintain applications in a uniform fashion with less time and resources spent monitoring the supporting network and network services for those applications.
• #13: Datacenter Operating System is, as the name implies, an operating system for for a datacenter rather than for a phyiscal of virtual machine. DC/OS abstracts away the underlying hardware from applications and provides much of the needed infrastructure that would otherwise come from multiple disparate services on traditional networks. This enables operations and developers alike to deploy and maintain applications in a uniform fashion with less time and resources spent monitoring the supporting network and network services for those applications.
• #14: Kubernetes is an open-source platform for automating deployment, scaling, and operations of application containers across clusters of hosts, providing container-centric infrastructure. With Kubernetes, you are able to quickly and efficiently respond to customer demand: Deploy your applications quickly and predictably. Scale your applications on the fly. Seamlessly roll out new features. Optimize use of your hardware by using only the resources you need.
• #15: Docker Inner Loop => Everything you do before you commit your code Pull the base image from Registry, such as Docker Hub Commit Source Code to Repository such as VSTS Build System takes the code, Docker described the build system., create images Docker image pushed to the registry with Environment configuration extracted During Deployment, pull the images and push to various environments
• #16: Docker Inner Loop => Everything you do before you commit your code Pull the base image from Registry, such as Docker Hub Commit Source Code to Repository such as VSTS Build System takes the code, Docker described the build system., create images Docker image pushed to the registry with Environment configuration extracted During Deployment, pull the images and push to various environments
• #17: Docker Inner Loop => Everything you do before you commit your code Pull the base image from Registry, such as Docker Hub Commit Source Code to Repository such as VSTS Build System takes the code, Docker described the build system., create images Docker image pushed to the registry with Environment configuration extracted During Deployment, pull the images and push to various environments