Towards the Endless Possibilities: Exploring the Wonderful World of Docker Container Technology

foreword

Have you ever wanted to package an application and all its dependencies into a self-contained, portable container that can run anywhere in any environment? Yes, that's the magic of Docker! Docker has become the swiss army knife of modern software development and deployment, allowing developers to build, deliver and run applications like never before. Now, let us explore the world of Docker together and uncover the mystery of container technology!

History of Docker

Docker was created by Solomon Hykes and his team in 2013. It was originally an open source project to solve the problem of application dependencies and deployment in different environments. Since its release, Docker has garnered a lot of attention and adoption, quickly becoming the leader in containerization technology. The following is the development history of Docker:

2013: The birth of Docker
In 2013, Docker made its debut at the DockerCon conference and released version 1.0. The core idea of Docker is to leverage containers to package applications and their dependencies for fast, reliable and portable delivery.

2014: The Popularity of Docker
In 2014, Docker started to gain widespread recognition and adoption. More and more developers and organizations are experimenting with Docker to build, deliver, and run applications. Docker Hub (Docker's public mirror warehouse) was also launched in the same year, providing users with a convenient mirror sharing and acquisition platform.

2015: Docker's Ecosystem Development
In 2015, the Docker ecosystem began to grow rapidly. Docker introduces Docker Compose (formerly known as Fig) to make orchestrating multi-container applications simple and easy. At the same time, Docker introduced Docker Machine and Docker Swarm to better manage and scale container clusters.

2016: Docker Standardizes
In 2016, Docker became the de facto standard for containerization technology. Docker released a container runtime (Containerd) and a container orchestration tool (Swarmkit), both of which became foundational components of the Open Container Initiative (OCI).

2017: Docker goes enterprise
In 2017, Docker evolved further into an enterprise-grade solution. Docker launched Docker Enterprise Edition (now called Docker Enterprise), providing enterprise users with a secure, reliable, and easy-to-manage containerization platform.

2019-present: Docker's continued innovation
In 2019 and beyond, Docker continued to introduce new features and improvements to meet the evolving needs of containerization. Docker continues to improve its products and tools to provide a better developer experience and higher performance.

[Dry goods sharing] 50 Docker questions and answers

What is Docker?
Docker is an open-source containerization platform used to package an application and all its dependencies into a self-contained, portable container that can run in any environment.
What is the difference between Docker and a virtual machine?
A virtual machine is to virtualize the entire operating system, and Docker is a container that virtualizes the operating system level. Docker containers are lighter-weight, faster to start, and can share the operating system kernel, making resource utilization more efficient.
What is the relationship between Docker images and containers?
A Docker image is a read-only template that contains all the files and dependencies needed to run an application. A Docker container is a running instance created based on an image, and can be started, stopped, deleted, and other operations.
How to create a Docker image?
A Docker image can be created using a Dockerfile, which is a text file containing a series of instructions for defining the build steps and configuration information for an image.
What is Docker Compose?
Docker Compose is a tool for defining and running applications in multiple Docker containers. It uses YAML files to configure the application's services, network and volumes, etc.
How to connect a container to a specific network? Containers can be attached to specific networks
using Docker commands .docker network connect
How to copy files into a running container? Files can be copied into a running container
using Docker commands .docker cp
How to view logs of Docker container?
You can use the Docker command docker logsto view the log output of the container.
How to execute commands in Docker container? Commands can be executed within a running container
using Docker commands .docker exec
How to list running containers?
You can use the Docker command docker psto list running containers.
Where are Docker images and containers stored?
Docker images and containers are stored in the file system of the Docker host, usually under /var/lib/dockera directory.
How to stop a running container? Running containers
can be stopped using Docker commands .docker stop
How to delete images and containers?
You can use Docker commands docker rmto delete containers and use docker rmito delete images.
How to build a custom Docker image?
You can use docker buildthe command to build a custom Docker image, you need to provide a Dockerfile and the corresponding build context.
What is Docker Hub?
Docker Hub is a public Docker image repository from which various official and community-maintained images can be obtained.
How to push the local Docker image to Docker Hub?
You can use docker pushthe command to push the local Docker image to Docker Hub. First, you need to create a repository on Docker Hub and tag your local image with the name of that repository.
How to set resource limits for Docker containers? Memory and CPU limits for containers
can be set using the and options docker runof the Docker command.--memory--cpu
How to expose ports in Docker container? Options to
the Docker command can be used to map a container's port to a port on the host.docker run-p
How to share data between Docker containers?
You can use Docker's data volumes to share data between containers. Data volumes can be created using docker volume createcommands and mounted into containers.
How do I view the details of a Docker image?
You can use the Docker command docker inspectto view the details of the Docker image.
How to export files from Docker container?
You can use the Docker command docker exportto export the files in the container as a tar file.
How to set environment variables for Docker container? Environment variables for containers
can be set using options to the Docker command docker run.-e
What are the network modes of Docker?
Docker's network modes include bridge, host, none, overlayand macvlanetc.
How to install a package in a docker container?
You can use the instructions in the Dockerfile RUNto install packages in the container.
How do I delete all unused Docker objects (images, containers, volumes, etc.)?
You can use the docker command docker system pruneto delete all unused docker objects.
Can Docker containers access devices on the host machine?
Yes, it is possible to map devices on the host machine to containers using the options docker runof the Docker command.--device
How to set up automatic restart of Docker container?
You can use the options docker runof the Docker command --restartto set the automatic restart policy of the container.
How to run background tasks in a docker container?
You can use options to the Docker command docker runto -drun containers in the background.
How to view the statistics of Docker container (CPU, memory, network, etc.)?
You can use the Docker command docker statsto view the statistics of the Docker container.
How to configure DNS server in Docker container? A container's DNS server
can be configured using options to the Docker command docker run.--dns
How to debug an application inside a running Docker container?
You can use Docker commands docker execto execute debugging commands in a running container, such as outputting logs, checking processes, and so on.
How to run a periodic task in a docker container?
You can set up a periodic task in a Docker container using tools such as Cron.
How to access files on the host machine from the Docker container?
You can use the options docker runof the Docker command -vto mount files or directories on the host machine into the container.
How to run a web server in a docker container?
You can use options docker runto the Docker command -pto map a container's port to a port on the host machine and run a web server inside the container.
How to limit the CPU usage of a Docker container? You can limit the CPU usage of a container
using options to the Docker command docker run.--cpus
How to run a database server in a docker container?
You can use Docker commands docker runto run a database server container and connect it to other containers.
How to run a backend application and a frontend application in a docker container?
You can use Docker Compose to define and run multiple containers, each running a backend application and a frontend application.
How to run a database migration script in a docker container?
You can put the database migration script in a container and use the Docker command docker runto run the container to execute the database migration script.
How to deploy a multi-node cluster application using Docker?
A multi-node cluster application can be deployed using container orchestration tools such as Docker Swarm or Kubernetes.
How to configure persistent storage for Docker containers?
Persistent storage for containers can be configured using Docker's data volume feature or a network storage solution.
How to set custom hostname for docker container? You can use options to
the Docker command to set a custom hostname for the container.docker run--hostname
How to execute scheduled tasks in Docker containers?
You can use tools such as Cron to set up scheduled tasks in Docker containers.
How to use environment variables in Docker container? Environment variables for containers
can be set using options to the Docker command docker run.-e
How to set resource limits (memory, cpu, etc.) for a docker container? Container resource limits can be set using the and options of
the Docker command .docker run--memory--cpus
How to set up inter-container communication in a Docker container?
You can use the Docker network function to create a custom network and use this network to communicate in the container.
How to set multiple environment variables in a docker container? Multiple environment variables can be repeatedly set using the options of
the Docker command .docker run-e
How to access environment variables on the host machine from the Docker container?
You can use the options docker runof the Docker command --env-fileto read environment variables from the host's environment variable file and use them in the container.
How to debug a crashed application in a docker container?
You can use Docker commands docker execto run debugging tools inside a container and attach to a crashed application process.
How to build a multi-stage build process with Docker?
You can use the Docker multi-stage build function to define multiple build stages in a Dockerfile and pass the build results to the next stage.
How to run a GUI application in a docker container?
GUI applications can be run by installing an X11 server in a Docker container and forwarding the GUI display to the host machine.

Summarize

Docker has started a revolution in the field of software development and deployment, it has brought us infinite possibilities and convenience. With Docker, we can easily build, deliver, and run applications, whether in a development environment, a test environment, or a production environment. It makes software development more flexible, reliable and efficient. Whether you are a developer or a system administrator, mastering Docker technology will be a powerful skill in your career. Continue to explore and learn Docker, let our applications soar in the ocean of containers!