M6 - Lesson 1: Overview of containers in Windows Server 2016 (Container…
M6 - Lesson 1: Overview of containers in Windows Server 2016
What are Windows Containers
Containers provide an isolated operating environment that you can use to provide a controlled and portable space for an app.
The container space provides an ideal environment for an app to run without affecting the rest of the operating system (OS) and without the OS affecting the app. Containers enable you to isolate apps from the OS environment.
In many ways, containers are the next evolution in virtualization. Containers are also referred to as container-based OS virtualization. Although containers run on the host OS, containers are isolated from one another. Isolated containers improve the security and the reliability of the apps that run within the containers.
Types of containers
Windows Server containers:
These containers provide app isolation through process and namespace isolation technology. Windows Server containers share the OS kernel with the container host and with all other containers that run on the host. While this provides a faster startup experience, it does not provide complete isolation of the containers.
These containers expand on the isolation that Windows Server containers provide by running each container in a highly optimized virtual machine (VM). However, in this configuration, the OS kernel of the container host does not share with the Hyper-V containers.
This element consists of the physical or virtual computer that is configured with the Windows containers feature. The container host can run one or more Windows containers.
As modifications are made to a containers file system or registry, these changes are captured in the container’s sandbox. In many cases, you might want to capture the container image state so that the new containers that you create can inherit the container changes. After you stop the container, you can discard the sandbox, or you can convert it into a new container image.
Each time you make a container image, the container image and its dependencies are stored in a local repository. This allows you to reuse the image many times on the container host.
Container OS image:
While containers are made from images, the container OS image is the first layer in potentially multiple image layers that make up a container. The container OS image provides the OS environment, and it is immutable.
This layer consists of all the changes made to the container, including file system modifications, registry modifications, or software installations. You can keep or discard these changes as required.
Windows Server containers
Hosting stateless apps
Rapid test deployment
Independent lifecycle management