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Docker is an open source platform that is free and easy to use. It is used to create, implement, and manage containerized applications. It helps developers to bundle programs into containers that can be run and executed in any given environment. In a traditional deployment, applications were deployed on physical servers and maintenance wasn’t easy, only 20-30% of resources were utilized. But in container deployment using Docker, an application is deployed through lightweight images, reducing the need of full-blown Virtual Machines to run applications, increasing the utilization to 70-80%. Docker increases time-to-market by 300%, developer productivity by 100%, deployment velocity by 60%, issue resolution rate by 70%, and IT operational efficiency by 50%. In the containerization market, Docker has a good market share of 82.50%, growing at a CAGR of 15.7%. Top industries such as Software Development, AI and ML, Big Data use Docker for Containers And Microservices. Companies such as Google, Amazon, Ford, Red Hat hire professionals adept in Docker containerization.
Docker is an open source platform that is free and easy to use. It is used to create, implement, and manage containerized applications. Containers simplify distributed programming, making them popular as companies shift to cloud-based development and multi-cloud hybrid setups. It helps developers to bundle programs into containers that can be run and executed in any given environment. Docker is also a toolkit that enables automation by allowing developers to use just one API to create, deploy, operate, change, and pause containers using easy commands. Development of containers can also be done without Docker, but using Docker makes the containerization process simpler, faster, and reliable.
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With rapid changes in business, the need for a tool that can meet business requirements at that pace has also increased. Docker containers help to deploy softwares into production easily with limited human interaction. It enhances developer productivity dramatically by ensuring that if code works great in a test environment, it will almost certainly function in production. Docker also has self-healing capabilities. If a container is not responding, it restarts it or creates a new one, making troubleshooting easier and faster. Thus we can say that the advantages of Docker are two-fold: reduction in Capital Expenditure and in Operational Expenditure. In a traditional deployment, applications were deployed on physical servers and maintenance wasn’t easy, only 20-30% of resources were utilized. But in container deployment using Docker, an application is deployed through lightweight images, reducing the need of full-blown Virtual Machines to run applications, increasing the utilization to 70-80%. Docker increases time-to-market by 300%, developer productivity by 100%, deployment velocity by 60%, issue resolution rate by 70%, and IT operational efficiency by 50%.
The container lifecycle is a series of stages, starting from the creation of the container, running of the container, updation of the container to its destruction.
1) docker - This command is used to display all docker commands
2) docker version - This command helps to find which docker version you are currently working on. It will display the current docker version and the build name.
Syntax: docker version
3) docker info - This command will display the information about the systems.
Syntax: docker info
4) docker pull - In a docker container lifecycle, the first thing we do is pull the images. This command helps in pulling images from the repository of Docker Hub
Syntax: docker pull
Example: docker pull centos
5) docker build - This command is used to build an image from a Dockerfile as well as a "context". The context of a build is the set of files in the supplied URL or path. Any of the files in the context can be referenced by the build process.
Syntax: docker build
Example: docker build -t apache_centos ( -t allots a tty and connects to stdin and stdout. Centos is the name of the docker image that created the container)
6) docker run - This command helps in running a container from a docker image. It adds a writeable layer to the picture specified in the command.
Syntax: docker run
Example: docker run e98b6ec72f51
7) docker commit - This command is used to create a new image from an already existing container file by committing container changes.
Syntax: docker commit
Example: docker commit e98b6ec72f51 ubuntu-centos
8) docker ps - If you want to see the list of all the operating containers, this is the command you should use. You can use the -a flag to view the containers including the stopped and paused ones.
Syntax: docker ps
9) docker start - This command will start one or more paused/stopped docker containers
Syntax: docker start
Example: docker start 6bfb1271fcdd
10) docker stop - This command will stop one or more running docker containers.
Syntax: docker stop
Example: docker stop 6bfb1271fcdd
11) docker logs - Use this command to see logs of a container. Viewing logs help in debugging issues.
Syntax: docker logs
Example: docker logs 6bfb1271fcff
12) docker rename - This command will rename docker containers.
Syntax: docker rename
Example: docker rename happy_world myfirstUbuntuContainer
13) docker rm - This command will remove a docker container. But to remove a container, you need to stop it first.
Syntax: docker rm
These commands execute docker containers containing images. We have listed some common Docker Image commands below:
1. docker build - This command is used to build an image from a Dockerfile
Syntax: docker build
Example: docker build -t apache_centos (Here -t allots a tty and connects to stdin and stdout. Centos is the name of the docker image that created the container)
2. docker pull - This command pulls docker images from docker hub repository.
Syntax: docker pull
Example: docker pull ubuntu
3. docker tag - This command will add a new tag to a docker image.
Syntax: docker tagimage/TAG
Example: docker tag reactjsdocker fosstechnix/reactjsdocker:v2.0
4. docker images - This command is used to display all the images installed on the system
Syntax: docker images
5. docker push - This command is the opposite of docker pull. It pushes docker images to the docker hub repository.
Syntax: docker pushName
Example: docker tag reactjs docker_registry.com/reactjs:v2.0
6. docker history - If you wish to view the docker image’s history, this is the command you should type in.
Syntax: docker image historyIMAGE
Example: docker history
7. docker inspect: This command is used to get low-level information on any of the Docker objects. This tool displays extensive information about the Docker-controlled constructs.
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Syntax: docker inspect
Example: docker exec -i -t 014528e786e0 /bin/bash (to access using container ID)
9) docker logs - Use this command to see logs of a docker container. Viewing logs help in debugging issues.
Syntax: docker logs
Example: docker logs 6bfb1271fcff
10) docker rename - This command will rename docker containers.
Syntax: docker rename
Example: docker rename happy_world myfirstUbuntuContainer
11) docker rm - This command will remove a docker container. But to remove a container, you need to stop it and then remove it.
Syntax: docker rm
12) docker inspect - This command is used to get low-level information on any of the Docker objects. This tool displays extensive information about the Docker-controlled constructs.
Syntax: docker inspect
Example: docker inspect cbfa678479b6
13) docker attach - This command is used to connect terminals to an operating container to control operations such as input, output, and debugging.
Syntax: docker attach container ID/container name
Example: docker attach reactjs
14) docker kill - This command stops and removes containers.
Syntax: docker kill container <container……>
Example: docker kill $(docker ps -q)
15) docker cp - This command helps in copying files from your local system to a docker container.
Syntax: docker cp container:source_path destination_path|-
OR,
docker cp
Example: sudo docker cp 046828e786e1:/etc/ubuntu2 .(this will copy all files from the container to the host)
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These commands are used to execute various containers in one application. We have listed some important docker compose commands:
1) docker-compose build - As the name suggests, this command is used to build a docker compose file.
Syntax: docker-compose build
2) docker-compose up - This command executes and runs a docker compose file.
Syntax: docker-compose up
3) docker-compose ls - This command will help you see the list of docker images that are declared within the file of the docker compose.
Syntax: docker-compose ps
4) docker-compose start - This command starts already created containers in a file.
Syntax: docker-compose start
5) docker-compose run - This will help you to run an application within docker-compose.yml
Syntax: docker-compose run reactjs
6) docker-compose rm - This command removes containers from docker compose files.
Syntax: docker-compose rm -f
7) docker-compose ps - This command helps in checking the status of a container from the compose of the docker.
Syntax: docker-compose ps
These commands are used to create, remove, and inspect docker volume. Here is a short list of the basic commands:
1) docker volume create - This command creates volume for docker.
Syntax: docker volume create
2) docker volume inspect - This command inspects docker volume.
Syntax: docker volume inspect
3) docker volume rm - This command is used to remove the volume of the docker.
Syntax:
docker rm –f $(docker pq -ak) (This removes the docker container)
docker volume rm(This removes the volume)
These basic commands listed below will help you to create, view and list docker networks and network configuration details.
1) docker network create - This command creates a network for docker.
Example: docker network create -d bridge our-network
2) docker network ls - Use this command to list all docker networks.
Syntax: docker network ls
3) docker network inspect - This command is used to view and inspect details of docker network configuration.
Syntax: docker network inspect
To view and monitor docker containers, use the following commands:
1) docker ps -a - This command is used to display all operating as well as stopped containers.
Syntax: docker ps -a
2) docker logs - Use this command to view logs of a docker container. Viewing logs help in debugging issues.
Syntax: docker logs
Example: docker logs 6bfb1271fcff
3) docker events - This command fetches all events related to the docker.
Syntax: docker events
4) docker top - If you wish to view the running process of a docker, use this command.
Syntax: docker top
5) docker stats - This command helps in checking and monitoring the usage of processing units, memory devices, and network input/output devices.
Syntax: docker stats
6) docker port - Use this command to view public ports of the docker container.
Syntax: docker port
These set of commands help to erase unused or hanging docker objects such as images, networks, containers, and volumes.
docker system prune - This command will clean resources which are hanging or not related to any containers.
docker system prune -a - This command will remove docker images that are not being used or have been stopped.
docker image prune - This command will remove lingering docker images.
docker image prune -a - This command will remove lingering docker images.
docker container prune - This command removes docker containers that have not been used.
docker volume prune - This command removes docker volumes that have not been used.
docker network prune - This command removes docker networks that have not been used.
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1. docker search - This command is used to search for docker images.
2. docker pull - This command pulls the image from docker hub.
3. docker push fosstechnix/nodejsdocker - This command pushes the image to the docker hub.
4. docker logout - Use this command to log out from the docker hub repository.
Conclusion:
With rapid changes in business, the need for a tool that can meet business requirements at that pace has also increased. Using Docker makes the containerization process simpler, faster, and reliable. Docker containers help to deploy softwares into production easily with limited human interaction. It enhances developer productivity dramatically by ensuring that if code works great in a test environment, it will almost certainly function in production.Thus we can say that the advantages of Docker are two-fold: reduction in Capital Expenditure and in Operational Expenditure. By learning Docker, you will not only stay abreast and competitive in your field but way ahead of your peers.
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