‘Docker’ would have been a familiar term for those working with cloud or data centre services. Docker has emerged as a greatest container technology within a year. Docker 1.0 was released this June and Docker buzz turned into a roar after this. Major companies started adopting this technology at high rates. There are wide ranges of businesses that move their application servers from virtual machine to Docker containers. Major bank leaders and IT companies have adopted this Docker technology.
Docker is open-source application as like Canonical and Red Hat of Linux. Microsoft has also moved to Docker technology. The major reason for adopting Docker technology is its advantages over virtual machines. The Virtual machine’s hypervisors need a bulk of host system resources whereas the light-weight Docker technology uses just the kernel and libraries of the host. Docker avoids performance overhead, cost overhead and ultimately offer better performance. Dockers are viewed as small capsules for holding entire application. Still, the use of Docker is debated widely. Docker has few disadvantages like lack of GUI, command-line operations, and much more which are questioned by developers. Docker finds its way into real world applications with its advantages.
In this chapter, we will discuss about the differences between virtual machines and Docker in terms of advantages and disadvantages, the best and worst Docker sides and finally the real world applications of Docker technology.
Debate of the Day- Is Docker Technology or Virtual Machines Useful?
Docker technology has many uses and can readily occupy any client environment. Docker has very apparent usage in Developer platform. But there is a debate going on between clients and Docker developers if Dockers are really useful against Virtual Machines.
Listed below are few points why Docker is used for Flux 7 that uses DevOps:
The application which is under manufacture has Ruby on Rails having huge coding and also Nginx Apache server, Redis, Memcached and MySQL. The website is completely for AWS or Amazon Web Services based on subnets and Virtual Private Clouds. Imagine that you have used Chef for setting up LogStash (logging system), Zabbix (monitoring system) and also for DevOps. The query that arises now is how to optimize the developer flowing at best? The best solution that anyone would propose is by using Docker application.
Is it good using Docker application for developing complicated websites?
This query will lead to very useful discussion and listed below are four important reasons why Docker application must be used in a developer platform:
1. Operating Expenses for Performance
There lies a great difficulty in using multiple Docker containers on a portable device like laptop when compared to Virtual Machines. The local configuration must act like single entity for each tier, same to production, alternative to installing all laptop’s software under a single IP address. The actual question in mind is about using six Docker containers or six VMs. The major drawback of using six Virtual Machines is that the laptop would get tanked. VitualBox on the other hand is not a good virtual machine manager and thus either Parallels or VMWare need to be used. There is much research needed on this topic to discover whether Docker or VM is best, though the conclusion seems neutral for both Docker and VM in this case.
Docker has the capacity for creating or deleting a clear environment fast. Docker usage makes a huge difference in applications like developing cooking recipes which needs a clean platform at each time when a failure is faced. In regular kind of Ror development environment, a clear environment is not necessary and thus Fastboot protocol is
convenient though not mandatory. There is a strong thought that cookbooks and DevOps can easily be debugged effectively using Docker.
3. Compact Container Size and Wide Availability of Different Containers
While sharing of a Virtual Machine in a remote environment is difficult, it is completely possible and easier to share Docker containers with the help of Docker registries. Docker has the capability to pull constructive changes and thus scored the current point. This ability of Docker has advantages in majority of web applications.
4. Container Ability to Run both on Cloud and AWS
One cannot run VMWare on Amazon Web Service but Docker technology provides the ability to run Docker container on AWS. In addition, Docker containers can be run parallel on Cloud as well- the same Docker container can run on both VMWare and Cloud. This is a great positive point for Docker.
Docker is best suitable for applications like AWS or cloud services.
For Docker users, listed below are crystal clear advantages of Docker that none can argue against:
1. Potential for shifting to various Docker Containers: This enhances debugging and provides faster environmental sharing and also faster deployment rates. There is no competing technology for Docker for this feature.
2. Ability for debugging DevOps: You can overcome the slow booting of AWS instances or VM with the help of Docker.
3. The capability to move Docker containers from QA or Dev to AWS, directly.
The Docker application’s container technology has become very popular and made a mark in various Information Technology environments. With the growing demand for Docker, the Docker technology is believed to stay strong in IT industry for longer periods of time.
The debate is lasting forever about the major advantages and best application areas of Docker technology. There is another question in mind- how to more reasonably take Docker forward, avoiding alienating the present users or damage for the utilities. Let us take a quick glance of what are the best and worst sides of Docker.
Let us hear the best side of Docker from great personalities who are experienced in IT and Docker technology.
Steve Francia is the chief operation head of Docker Technology project and he speaks all best things about Docker. He says about the best features of Docker as, “I feel that the best feature of Docker is that Docker validates users, developers and people to conveniently run a Docker application on any environment. Docker is anything like ‘Holy Grail’ in application development as you can run a Docker application on your personal computer and the similar application on server, without making any changes. This has never been possible with any past technologies.”
The CEO of Weaveworks, Alexis Richardson complimented Docker application for enhanced simplicity. According to him, Docker provides a great potential for radical simplification and speedy operation during software development. He feels that this is the reason for surpassing record of Docker in getting huge initial sharing and purchase. Weaveworks is a leading company that operates with virtual networking.
Bob Quillin, the chief executive officer of StackEngine declares that the Docker technology has maintained its appealing nature with its users. According to him, Docker is best for delivering better support for developers and pivoted investment in Docker’s products. StackEngine is a company which is working with Docker automation and management technologies. More clearly, Docker application knows the secret of maintaining this momentum and this is achieved by continuous efforts which are put for functionality of products, he believes. The CEO also quoted about Docker’s leading commitment for open source technologies- the Dockers allow acceleration of production adoption by enabling people for building applications in the right way.
Rob Markovich, the author of great IT monitoring company named ‘Moogsoft’ believes that the Docker makes containerization the latest, though container technology is old. Docker is going to take virtualization to next generation by providing the light-weight and modern container format of it, he comments. According to him, Docker will take software development methods a step forward by providing highest magnitude of order and faster deployment speed.
The least appealing thing about Docker lies basically on a couple of issues namely: complexity of Docker usage and company direction behind Docker.
The CEO of Platform as a Service enterprise, Samir Ghosh hails Docker for simplification of complicated scripts which are normally needed for uninterrupted delivery. He also added that Docker is never simple as it delivers simpler scripts. Docker implementation is quite complex. A load of technological supports are necessary for Docker implementation including orchestration, container management, app stack, data screenshots, networking of containers, and so on.
Samir pointed that the people who are in great pain are IT enterprises which are using Docker for uninterrupted delivery. It is really a difficult situation for enterprises to have different application stacks, different kinds of workloads, infrastructure of heterogeneous nature, and restricted resources. The unique needs for IT namely control, transparency and security are other complicated factors with Docker usage.
Complex nature of Docker has also affected analysis and debugging. Markovich denoted the fact that application abstractions are provided by Dockers for this. It is quite not possible in relating problems of basic infrastructure domains with the Docker application’s performances. He believes that IT developers require visibility as a recent monitoring standard and analysis which correlates the working of all applications on Docker stack to the applications on public or private infrastructure.
Quillin is more involved with direction of Docker in related to its associated community. The question where Docker or its partners will make money is still unanswered. A flourishing ecosystem must be created if in case Docker technology wants to be the next biggest VMWare, by removing a page from playbook of VMWare methods in building and supporting partner ecosystems.
Docker is required to act similar to market lead by delivering more entirely formed capacities which the IT organizations can rely upon, against feature announcements with statements such as ‘certain assemblies required’, ‘this never exists still, or this wants you to ‘fix it by yourself or create a pull request’.
Francia noted Docker’s high progress rate to create its self-complications. Docker gets caught so quickly and there are definitely various places for adding extra features which many Docker users look forward for.
One of the features that can be added by Docker is Graphical User Interface or GUI. For using Dockers currently, one must be well-aware of command line. There are no graphical interfaces for Docker in current scenario. All Docker commands are command-line dependent. If a technology wants to create success among the audience, it must be user-friendly as well. For many of the users of Docker, command-line seems to be quite difficult.
Docker has started making advancements, recently. Initial Kitematic was released recently which will propose a convenient Graphical User Interface for Docker with Mac operating system and Windows. Another technology called SDN of SocketPlane have been adopted by Docker.
The major debate is whether Docker will solve its problems and emerge as a best solution for enterprises or if Red Hat is going to provide more useful and immediate solution to enterprise as the enterprise customers cannot wait till Docker modifies itself. As customer expectation starts building wild and need for new features arise, Docker suffers in this area in spite of its various advantages. It will surely take more time for rebuilding Docker application.
Docker offers light-weight nature of virtualization, involving no overhead. This helps in delivering few vigorous advantages.
The very first advantage is that users get benefitted from additional layer abstraction by Docker, preventing performance overhead. The next advantage of Docker is that the users can have multiple Docker containers that run on same machine, which is made possible by virtualization.
The other major impact is that Docker container’s bring-down and bring-up can possibly be accomplished in few seconds of time.
Listed below are few cases that enable Docker technology for providing consistent platform with least overhead.
This is the prime usecase that Docker Inc advertises about. One major advantage with Virtual Machines is the tendency to execute on any platform using its self-configuration above your infrastructure. Docker offers similar ability but without any overhead as like VM. Docker enables you to deploy it on any environment by configuring specific code. A single Docker configuration is capable of running in various environments. This will detach the requirements for infrastructure from application development area.
The previously seen use case brings great influence to pipeline’s code management. As the coding traverses from developer machine into production area, it has to pass through various different platforms to reach there. Each of these environments has small differences. Docker creates an integrated environment for application to travel from
developer to production, creating easier development and deployment standards for pipeline code.
This will lead to extra advantages. Docker has a well suited developer productivity use case. In the dev environment, there are two major aims that conflict with one another. We need Docker to be used closer to production and at the same time we need dev environment to run as quick as possible for user interaction.
For achieving the first aim, we must have each service to run on the service’s own virtual machine for reflecting the way application is running. At the same time, we never need to require internet connectivity always which adds up to compilation overhead while working remotely. Here lies the 0-overhead feature of Docker technology. The Dev environment normally runs short of memory. Using of a virtual machine will add to memory overhead, which is overcome by Docker technology.
There are multiple reasons for developers to run many applications on a single machine. For example: Dev productivity flow as seen in previous case. There are other reasons also.
Few reasons to take into consideration are minimizing cost or planning gradually in separating monolithic environment into decoupled pieces. There are many advantages in developer point of view for decoupled application.
Similar to VM usage to consolidate many applications, isolation of applications can be easily achieved through Docker. Docker has capability to consolidate multiple server for cost saving. Without multiple operating system’s memory footprints, Docker has ability of sharing unused pieces of memory across various instances. Docker offers
denser server grouping mechanism than virtual machines.
Docker offers many tools which are not always container-specific. They all have best working capapcity with all container types. These tools of Docker also offer useful functionalities. These functionalities include capacity to version the containers and also to checkpoint, which is extended to two various container types. This is highly helpful
for fixing application bugs.
The other interesting Docker use case is its ability to co-operate for multi-tenant platforms, which avoids rewrites for many applications. The best example for multitenancy is developing fast and convenient multi-tenancy application for IoT. The actual code fundamentals involved in these multi-tenant applications are quite complex, unchangeable and hard to handle. Re-structuring an application causes huge cost overhead as well as time-consuming.
With the help of Docker, it is inexpensive and easier for creating environments that are isolated from each other, to run multiple tenant instances in an application tier. The high spinning speed of Dockers and effective commands are helpful for these kinds of applications.
Before the use of virtual machines, it took large number of days to build a hardware resource newly. Virtualization concept has reduced days to minutes. Docker, on the other hand has brought this count to seconds. Docker just creates Docker containers for specific processes but never boots the operating system. Even the leading companies like Facebook and Google make use of container technology- Docker, mainly due to this reason of quick deployment.
It is very easy for creating as well as destroying resources on data centres without bothering about rebuilding costs. With the help of more rigorous resource allocation methods, utilization rates of data centres can be easily hiked. The cheap cost in building new instances with Docker enables high allocation of resources.
The use cases of Docker are not limited to the above; there are many other available for building proper solutions for your business. The Docker has enlarged from secured toempowerment of developer platform.
The right motivation behind Docker usage is the satisfaction of choosing correct tool for appropriate job types. Start with business use case and enlarge from there.
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