Introduction to Docker Architecture
This Docker technology uses the Linux kernel like Cgroups and namespaces to separate the process and make them run without any dependencies. This independent feature is the one which made docker as a successful one by running individual instance or application at the same time and made a better utilization of infrastructure. Docker and container tools provide an Image-based deployment model which makes it easy to share an application across multiple environments. The tools built on top of containers makes Docker unique, rapid, flexible, independent and user-friendly. In this topic, we are going to learn about Docker Architecture.
What is Docker?
The word Docker comprises several things like tools from an open-source project, the primary supporter of the project and the tools which the company directly supports. In the IT field, the Docker is containerization technology which is used to create and use Linux containers. The Open source docker community works to enhance these technologies to get more benefits for users. The enterprise that builds on the Docker community makes it more reliable, secure and facilitates and shares the advanced feature to the enterprise. With Docker, it is easy to control the containers like lightweight, modular and virtual machines and also used to create, deploy, copy and move them from surrounding to the surroundings.
Docker Engine is an important part of the complete system. Docker Engine is a service that abides by client-server infrastructure is set up on the guest machine.
The important three components are
- Server: The server is the docker daemon called dockerd which can manage and create Docker containers, images, networks, etc
- Rest API: Rest API controls docker daemon on its processes
- CLI: Command Line Interface is a user interface that is used to input commands in the docker
Docker Client: Users of Docker can communicate with Docker via the host. If any docker command runs, the host moves them to docker daemon, which takes them out. API of docker is handled by commands from the docker. Docker client can enable to interact with multiple instances.
Docker Registries: Docker hub is the storage place for Docker images of a public registry. It can either used as a private docker registry or a public docker registry. Clients can also create and execute their own private registry
Clients functioning with Docker, use volumes, containers, images, networks, and all the docker objects available
Images of the docker are in read-only standard with commands to design a new docker container. Image of docker can be retrieved from a hub of docker and utilized. It can add extra steps to the last image and design a modified docker image. A Client can create his docker images by using a docker file. The first step is to make a container that creates a docker file and with required instruction creates own docker image. Docker image, an underneath layer is read-only, and the first layer can be written. A client can edit and modify only the top layer of a docker image.
Docker container is created after running a docker image. All the instances and applications run inside the container. A client can use Docker API to delete, start or stop the container.
This is a sample command to execute a docker container:
docker run -i -t ubuntu /bin/bash
The present data executed by docker is utilized by Docker containers and saved in Volumes. The entire system is controlled through API if the docker. Volumes applied on both Linux and Windows platforms. Instead, to edit information in an editable layer of container, it is better to utilize volumes for writing Volume’s content is present outside the container, so it doesn’t affect the container’s size and properties
use -v or –mount flag to initiate a volume in a container.
If the client uses geek volume with the container,
docker run -d –name geekflare -v geekvolume:/app nginx: latest
Docker networking is a communication passage for all isolated containers.
The network drivers in docker: The bridge is the fixed network driver for a container. clients occupy this network for applications running on self-supporting containers, i.e. many containers interacting with common docker hosts. The host is a driver eliminates the network segregation between docker containers and docker host.
Overlay: The network renders team services to interact with others. This is applied only if the container is executing on multiple Docker guest or team services generated by many applications. A driver disconnects all the networking is called as a None driver
Macvlan: The driver assigns a unique address in MAC to all containers to resemble them like hardware systems. They control the traffic in between containers with their MAC addresses. The network is enabled if needed. for example, when the migration of virtual machine setup.
Let us see some of the Benefits of Docker
- Return on investment & cost savings: Docker can reducing the cost by facilitating minimal infrastructure resources. It allows the engineering system to be cost-effective because of wide applications running on a simple set up
- Standardization & productivity: Docker provides standardization by providing continuous development, deployment, and testing to the servers in the production environment. It is fast which allows making replications and redundancy.
- CI efficiency: It builds the docker image and the same is effectively used for the whole deployment process.
- Compatibility & maintainability: It is more portable and easy for installation and debugging.
- Simplicity & faster configurations: Data can be created and destroyed in a fraction of seconds in an affordable range in a minimal response time.
- Rapid Deployment: it manages deployment to seconds for a wide range of environment
- Continuous Deployment & Testing: Docker ensures logical environments from development to production. Docker containers are configured to manage all configurations and dependencies internally. So, the client can use the same container from development to production for no discrepancies or manual intervention.
Docker supports Multi-Cloud Platforms like AWS, GCP and allows instances to run inside amazon EC2 instances, Rack space servers or virtual box. It also supports Microsoft azure, open stack to manage chief, puppet and ansible. The benefit of using docker is security. Docker checks that instances running on containers are completely separated and isolated each other, providing control over traffic flow and management. when a client runs a docker pull or docker run commands, the desired docker image is pulled from the configured registry. When a client runs a docker push command, the docker image is stored on the configured registry.
This is a guide to Docker Architecture. Here we discuss the Architecture, Objects and the benefits of Docker with the network drivers. You may also have a look at the following articles to learn more –