Guide to Containers
"Every application needs extra storage space to offer smoother functioning, and that is done by containers"
What are containers?
A software program or application does not run in a single environment. Several actions must be performed in various locations, and this requires a high level of skill. Just relying on basic storage methods and software isn't good enough.
In simple terms, containers are software units that store the code necessary for an application to run. Containers are a standard unit of software that packages the executable code along with its dependencies like code, runtime, configuration, libraries, files and so on.
By wrapping all the codes that are required to run the application, it is easy to execute the program. It also helps in quickly running the program from one environment to another. It is known as the package that contains all elements that are required to execute a program.
Containers VS Virtual Machines
The concept of virtual machines has been a traditional one in the computing world. VM's virtualize the physical hardware on which the application runs, more concerned with the virtualization of the system that the application runs on.
VM consists of a guest OS that runs above the actual operating system and this guest OS consists of all dependencies related to the application. Containers, on the other hand, virtualize the actual operating system of the application to run the application along with its libraries.
- Containers don't need to boot or load the OS, like VMs.
- Containers are lighter than VMs.
- Containers virtualize the OS, whereas VMs virtualize the hardware of the application.
Benefits of containers
Developers benefit from containerization because the software runs faster and the process is smoother than before. These containers have significant benefits in making the process easier. The lightweight of containers:
As mentioned before, containers are lighter than VMs. It is lightweight, making the container files small and easier to access. As the containers are a part of the OS of the applications, there is no need for an additional OS.
Highly efficient - The efficiency of any product matters, for it to work effectively and meet our requirements. In that case, the use of containers helps the applications run, deploy, and patch more quickly.
Secure - Though containers share a part of the operating system, they do not interact with other components of the OS. In case there is an issue or bug in the container, it only affects the container and not the other parts of the OS.
Consistent operation - The software doesn't work in a single environment, to work in various environments its performance has to be consistent. These containers offer consistent functionality, no matter where the application is being run or deployed.
Increased portability - All the dependencies related to the code are stored within containers, as well as the code itself. Consequently, when changing between environments, all the related elements are also moved to the newly created environment, making the containers portable.
What is Containerization?
Just learning about containers isn't enough. Understanding the process behind it is also imperative. Containers virtualize the OS, which makes the application run faster, and this virtualization process is known as containerization.
Containerization is the process through which containers package all the codes, libraries, files and other dependencies of the application so that the software can be deployed in any suitable environment.
Building blocks of containers
There are three basic building blocks of containers, and they are:
This is a key feature of containers that helps in isolating the various processes that an OS performs. A software or a server contains various operations and processes that work together.
The container namespaces isolate each server and its process, which helps the developer to work in an isolated environment easily. Every container can have multiple namespaces related to the OS.
#2 Control groups:
Control group or cgroup is a kernel feature that helps in the resource management of containers. During its operation, it controls CPU, memory, and network utilization by containers.
Cgroups provide the following advantages:
- Resources can be limited, i.e., how much of a resource each container can use and the resource limit each Cgroup can access.
- Containers can monitor every resource they use.
- The process of CGroups in containers can be controlled, started, or frozen.
#3 Union file systems:
The container contains various libraries and codes for the application. UnionFS is a feature that helps in providing us with a unified view of all the dependencies present in the container, i.e., it makes the files stackable.
The different files, directories and libraries can be viewed easily in the form of a single file system using UnionFS.
Docker and Kubernetes
Docker is a software platform known for its lightweight and standalone features, which is widely used in container applications. It uses docker images to run the application in multiple environments inside the container.
Using Docker containers can be very helpful in synchronizing the functions of the applications and packaging all the dependencies together for faster deployment.
Container orchestration is the operation through which multiple containers work together as a single system, and this is done by Kubernetes. These help in automating and scaling the workloads in different work environments.
Use cases of containers
Cloud applications: These applications have various work environments, such as public, private and hybrid. The use of containers helps in delivering cloud applications to the right environment easily.
Shifting: Migrating from one cloud application to another is common in any organization. Using containers can assist with easy migration without changing the code of the application.
Batch: It is the process of performing operations without manually operating them. The use of containers can make batch processing of operations more efficient.
To sum up,
- Containers are highly efficient and offer better performance in applications and software.
- It makes the program run and deploys faster, and the virtualization of the OS offers a consistent workflow.
- Using containers in cloud computing helps to reduce latency and outages.
When incorporated correctly into your workflow, containers can serve a variety of purposes.