Docker10 thing.

docker– 10 things you should know

Containers are not a whole new technology, but this does not prevent Docker from sweeping the world like a storm.

If you are in the IT circle, you must have heard of Docker. Even with other popular technologies such as Puppet/chef,hadoop or MongoDB, Docker is still a refreshing place to be.

But even if Docker is at its best, it doesn't mean it will be right for you. As I read in this tech Pro rearch analysis article,"You need to be cautious about whether to use Docker as the future technology direction for your business." "

Before you decide to try Docker, here are 10 points to know:

1. Docker is a software packaging and publishing technology

Modern software systems are generally composed of a variety of executable binaries, library files, configuration files, and other dependencies. It is very difficult and complicated to complete the assembly on a computer, and it becomes more complex to "release" the software. Once you start the publishing process, you need to find a way to get these components packaged properly, and consider how to put packaged software where they should go. Docker is a way to help you with software packaging, no matter how dependent your software is, where it is posted, other developers ' machines or production environments, and Docker provides you with an easy-to-use and standardized approach.

2. Docker is not a new technology

Docker has been around for several years, but container technology has been around for decades. Container technology has proven to be a very useful technology in the host era, making Docker's success look more like the result of a time-of-day hero, including the popularity of Linux, the proliferation of virtualized applications, and the rise of cloud computing that create the necessary conditions for Docker technology to be hot.

3. Basically everyone supports Docker

Whichever technology provider you choose, basically 100% of their support Docker. From Amazon AWS, to Redhat to Google, each has a good support for Docker.

4. Docker can not only run on Linux

Although Docker originated from the Linux platform, Microsoft is embracing Docker technology. Docker relies on many technologies that do not exist on the Windows platform, such as Linux container Technology (LXC), Cgroup, and namespace (namespaces) technologies. So Microsoft is working at the top of the window to provide the capabilities on Windows Server to integrate with Docker. In fact, Microsoft has been using its own containerized technology for many years in Windows, and now all it has to do is make these technologies better compatible with Docker because Docker has become a de facto standard.

5. Docker allows you to manage CPU, memory, network, and disk resources just like you manage virtual machines

Docker is implemented around Linux Cgroup, and Cgroup's role is to control the various computer resources that the container can use, including CPU, memory, network, and disk. At this point Docker provides the same capabilities as virtual machines, allowing you to allocate a portion of a computer's resources to a subset of users or processes so that they do not occupy all of the computing resources; Docker does not have as much waste of resources as VMware provides virtualization (virtual machines must run the entire operating system, and Docker simply virtualize the application).

6. Starting a Docker container is much faster than starting a virtual machine (millisecond vs. minute level)

The traditional way to run multiple jobs on a single server is to start multiple virtual machines and then run different jobs on different virtual machines. Because the virtual machine must start the entire operating system, it will be slow and typically takes a few minutes. These VMs are also very resource-intensive because the operating system itself consumes a lot of resources. Containers can solve the same problem, but starting the container and starting a process is the same level, so Docker allows you to save the resources wasted by the operating system, providing a process-level consumption that is similar to the virtual machine's isolation capabilities.

7. Docker does not completely replace virtual machines, at least in the short term

Docker is not a black-and-white alternative to virtual machines, mainly because Docker relies on the underlying standardized operating system, and virtual machines are the best way to solve this problem today. However, this also means that Docker is dependent on an operating system, so you won't be able to run both Windows and Linux applications on a single containerized host, and you need at least 2 containerized hosts running Windows and Linux separately. At the same time, as far as Docker's current technological developments are concerned, the container's isolation capability does not reach the same level as the virtual machine, so Docker may not be suitable for some multi-tenancy scenarios.

8. Docker is growing at a very fast pace.

Before you board the Docker train, you need to know that you are on a shinkansen instead of a steam locomotive, and that the speed of 400 kilometers per hour is not a joke. Look at this only 1.5 of the technology, its API has been released 15 versions, you will know how fast it changes. Even if Docker is fast maturing and has the ability to deliver enterprise-class software, it does not provide 10 years of technical support, which may be needed by many businesses.

Note: Now the version of Docker is already 1.12.

9. Docker is not a competitor

Although Docker is popular, it does not lack competitors. For example, CoreOS recently released a product called Rocket, and Docker's Best Linux companion, Ubuntu, is also developing its own LXD container technology. Many of these rivals are tearing up the Docker's closed ecosystem. In the Docker world, everything revolves around Docker registry, and you can either apply the public services provided by Docker or deploy a set in your own data center, which is not free.

There is a risk that Docker should be cautious in the market.

As with any emerging technology, you need to be gradual. From a technical point of view, you need to know a lot about what to do and what not to do. But most importantly, it's not just a few lines of code, you're entering an ecosystem, and the community may not be right for you. You should take part in some community activities, such as: Meetup, mailing lists, subscribing to the public number, and slowly understanding it, and then deciding whether to devote more time.

Regardless of Docker, container technology will continue to prevail, as containers make modern software technology and computer technology easier to use. In the realm of containers, Docker is the undisputed leader, and you have no way to avoid this fact. However, in the end how to accept, how much to accept, how fast, you must be based on the status of their business to consider.

Related reading:

Docker4dotnet #1 past life & World Hello
http://devopshub.cn/2016/07/08/docker4dotnet-1-overview-and-helloworld/

Docker4dotnet #2 containerized Host
http://devopshub.cn/2016/07/13/docker4dotnet-2-docker-machine-create-dockerized-hosts/

Dockercon 2016– What does Microsoft bring?
http://devopshub.cn/2016/06/22/dockercon-2016-with-microsoft/

Real-world docker:10 things We ' ve learned
Http://www.slideshare.net/rightscale/webinar-real-world-docker-2014-1209-v3-1

(This article may not be accessible on slideshare and can be obtained by entering D4dtools in the Devopshub subscription number)

Why Docker ... and why now?
http://www.techrepublic.com/article/why-docker-and-why-now/

Docker and Microsoft partner to bring container applications across platforms
http://news.microsoft.com/2014/10/15/dockerpr/#sm. 000UATMY5115TE5AVB62JYEQ9A5FG

Docker10 thing.