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A_docker_tutorial_for_beginners

Installation

1 Direct installation

Reference resources https://docs.docker.com/engine/install/

2 Installing from source

TODO: …

Use

1 image

1.1 Get from server

# Get the Ubuntu image with version number 22.04
$ sudo docker pull [image name]:[version]
  • image name: Image name.
  • version: Image version.

1.2 Load from file

$ sudo docker load -i [/path/to/load/image_file.tar]
  • /path/to/load/image_file.tar: Load file.

This operation contains meta data.

1.3 Display information

1.3.1 List images

# List all images
$ sudo docker images 
# List an image
$ sudo docker images [IMAGE ID]
  • IMAGE ID: Image id.

1.3.2 View detailed information for a specific image

$ sudo docker inspect [IMAGE ID]
# or
$ sudo docker inspect [REPOSITORY]:[TAG]
  • IMAGE ID: Image id.
  • REPOSITORY: Image name.
  • TAG: The version of image.

1.3.3 View the image history

$ sudo docker history [IMAGE ID]
# or
$ sudo docker history [REPOSITORY]:[TAG]
  • IMAGE ID: Image id.
  • REPOSITORY: Image name.
  • TAG: The version of image.

1.4 Modify information

$ sudo docker tag [IMAGE ID] [new_image_name]:[tag]
  • IMAGE ID: Image id.
  • new_image_name: New image name, new image REPOSITORY.
  • tag: New image tag.

1.5 Save image to file

$ sudo docker save [IMAGE ID] -o [/path/to/save/image_file.tar]
# or
$ sudo docker save [REPOSITORY] -o [/path/to/save/image_file.tar]
# or
$ sudo docker save [REPOSITORY]:[TAG] -o [/path/to/save/image_file.tar]
  • IMAGE ID: Image id.
  • REPOSITORY: Image name.
  • TAG: The version of image.
  • /path/to/save/image_file.tar: Saved Files.

1.6 Delete

$ sudo docker rmi [IMAGE ID]
# or
$ sudo docker rmi [REPOSITORY]:[TAG]
  • IMAGE ID: Image id.
  • REPOSITORY: Image name.
  • TAG: The version of image.

2 container

2.1 Display information

2.1.1 List running containers

$ sudo docker container ps
$ sudo docker ps

2.1.2 List all containers

$ sudo docker container ps -a
# or 
$ sudo docker container ps -l
# or
$ sudo docker ps -a
# or
$ sudo docker ps -l

2.1.3 View logs and status

View logs:

$ sudo docker logs [CONTAINER ID]
# or
$ sudo docker logs [NAMES]
  • CONTAINER ID: Container id.
  • NAMES: Container name.

View status, similar to top:

$ sudo docker stats

2.2 Delete

$ sudo docker rm [CONTAINER ID]
# or
$ sudo docker rm [NAMES]
  • CONTAINER ID: Container id.
  • NAMES: Container name.

Delete multiple non-running containers at once:

$ sudo docker rm $(docker ps -a -q -f status=exited)

2.3 Operation Container

2.3.1 Start

$ sudo docker start [CONTAINER ID]
# or
$ sudo docker start [NAMES]
  • CONTAINER ID: Container id.
  • NAMES: Container name.

2.3.2 Stop

$ sudo docker stop [CONTAINER ID]
$ sudo docker stop [NAMES]
  • CONTAINER ID: Container id.
  • NAMES: Container name.

2.3.3 Restart

$ sudo docker restart [CONTAINER ID]
$ sudo docker restart [NAMES]
  • CONTAINER ID: Container id.
  • NAMES: Container name.

2.4 Export and Import

# Export
$ sudo docker export [CONTAINER ID] -o [/path/to/export/container_file.tar]
# or
$ sudo docker export [NAMES] -o [/path/to/export/container_file.tar]

# Import. After importing, it is a image
$ sudo docker import [/path/to/import/container_file.tar]
  • CONTAINER ID: Container id.
  • NAMES: Container name.
  • /path/to/export/container_file.tar: Container export file.
  • /path/to/import/container_file.tar: Imported file: The file exported by the container.

2.5 Create a container

$ sudo docker run [OPTIONS] [IMAGE ID] [COMMAND] [ARG...]
# or
$ sudo docker run [OPTIONS] [REPOSITORY]:[TAG] [COMMAND] [ARG...]
# or 
$ sudo docker container run [OPTIONS] [IMAGE ID] [COMMAND] [ARG...]
# or
$ sudo docker container run [OPTIONS] [REPOSITORY]:[TAG] [COMMAND] [ARG...]

sample:

$ sudo docker run \
 			-p 20080:80 \ # Port Mapping: host-20080:docker-80
 			ubuntu:22.04 \ # use image: ubuntu:22.08
 			/bin/bash
...... 
$

2.5.1 OPTIONS

  • -d, --detach: Runs a container in the background and returns the container ID.
  • -p, --publish: Map the container’s port to the host. The format is: host_port:container_port.
  • --name: Specify a name for the container.
  • -e, --env: Set environment variables. The format is: VAR=value.
  • -v, --volume: Mapping the container’s directory to the host. The format is: host_path:container_path.
  • --hostname: Used to set the hostname of the container.
  • --restart: Used to set the container restart policy.
    • --restart no: Do not automatically restart (default).
    • --restart on-failure: Restart the container only if it exits with a non-zero status (can specify a maximum retry count).
    • --restart always: Always restart the container regardless of the exit status.
    • --restart unless-stopped: Always restart the container unless it is manually stopped.
  • -w, --workdir: Used to specify the working directory within the container.

2.6 Enter the running container

$ sudo docker exec [OPTIONS] [CONTAINER ID] [COMMAND] [ARG...]
# 或
$ sudo docker exec [OPTIONS] [NAMES] [COMMAND] [ARG...]

Enter the running container:

$ sudo docker exec -it [CONTAINER ID] /bin/bash

3 Dockerfile

3.1 Create container from Dockerfile

Creating a container from a Dockerfile

$ sudo docker build -t [image_name] [/path/to/find/dockerfile]
  • image_name: The name of the created container.
  • /path/to/find/dockerfile: Find the path of file Dockerfile.

3.2 Dockerfile core

  • FROM: Use the FROM directive to specify a base image.
  • RUN: Use the RUN command to install the required packages.
  • CPOY: Use the COPY instruction to copy local files into the container.
  • ENV: Use the ENV command to set environment variables.
  • WORKDIR: Use the WORKDIR directive to set the container’s working directory.
  • LABEL: Use the LABEL directive to add maintainer information.

sample

Dockerfile for creating a C++ development environment based on Ubuntu 22.04.

(1) Create Dockerfile

Dockerfile

# Use ubuntu22.04
FROM ubuntu:22.04

# Set maintainer information
LABEL maintainer="your_email@example.com"

# Update package lists and install necessary packages
RUN apt-get update && apt-get install -y \
    vim \
    git \
    build-essential \ # Including GCC, G++, make and other compilation tools
    gdb \
    cmake \
    gdb \
    clang-format \
    clang-tidy \
    valgrind \
    lcov \
    doxygen \
    && apt-get clean

# Set the working directory
WORKDIR /app

# Copy local code into the container (if any)
COPY . /app

# Setting Environment Variables
ENV TZ=UTC
ENV LANG=en_US.UTF-8 \
    LANGUAGE=en_US:en \
    LC_ALL=en_US.UTF-8

# Expose a port (if necessary)
EXPOSE 8080

# Defines the command to be executed when the container starts
CMD ["bash"]

(2) Run the following command in this directory to build the image:

$ sudo docker build -t cpp_dev_env .

(3) Run the container using the following command:

$ sudo docker run -it --name my_cpp_container cpp_dev_env