Docker learning: dockerfile and docker-compose

Learn how to use dockerfile

The following content is partly generated by gpt. There may be problems with the description, but I will test the code part.

1. Demand

For a docker, such as python, we need to have np when it is built into a container. There are two methods:

1. Pull python, and after running, pip install numpy in it, and then package and save the container.
2. When pulling python, run pip install numpy together. When running, there will be numpy.

2. dockerfile和docker-compose

Note: In order to achieve the above functions, dockerfile is used to define and build the instruction script of a single Docker image, that is, pull; docker-compose is used to define and run the tools and configuration files of multi-container Docker applications, providing a unified way to run.
Dockerfile:
Purpose: A Dockerfile is used to define the content and configuration of a single container. It provides a way to create a new Docker image from scratch, or customize a new image based on an existing Docker image.
Main operations: Define, build and configure a Docker container. Example uses: installing software, setting environment variables, defining working directories, setting entry points, etc. Usage: Use the docker
build command to create a new Docker image from a Dockerfile.
docker-compose:
Purpose: docker-compose is used to define and run multi-container Docker applications. It provides a declarative way to define a set of associated containers, networking between them, volumes and other configuration.
Main operations: Define, connect and manage multiple containers.
Example uses: running multi-service applications (such as frontend, backend, and database) in a local development environment, setting up network connections between services, defining and mounting volumes, and more.
Usage: Use the docker-compose up command to start the service based on the docker-compose.yml file.

3. Dockerfile

Use Dockerfile to implement python with numpy

1. Create a Dockerfile, the name must be strict

# 使用python:latest作为基础镜像
FROM python:latest

# 安装numpy
RUN pip install numpy

2. Create a mirror of the above content

# docker build -t image-name:latest <Dockerfile的路径>
docker build -t py-with-np:v1 .
# 使用 docker images查看已有镜像

3. Run the above docker

docker run -it -v /opt/appdata/python:/py --name pytest py-with-np:v1
# 使用docker ps -a查看运行的容器

4. docker-compose

The above dockerfile can only create images first and then run them, which is not elegant.
docker-compose solves this problem

1. Create Dockerfile:

# 使用python:latest作为基础镜像
FROM python:latest

# 安装numpy
RUN pip install numpy

2. Create docker-compose.yml:

Simple version, start python directly after running

version: '3'

services:
  hello-service:
    build:
      context: .
      dockerfile: Dockerfile
    image: py-with-np:v6
    volumes:
      - /opt/appdata/python:/py
    ports:
      - "8080:8080"
    command: python /py/test.py
    stdin_open: true
    tty: true

Explanation
: build: . instructs docker-compose to build the Docker image based on the Dockerfile in the current directory. image:
py-with-np:v1 specifies the name and label of the built image. volumes is a volume mapping, the same as the -v parameter in the previous docker run command
.
If you want to run a container in docker-compose and keep it interactive, such as an interactive Python shell, you should add a stdin_open and tty attribute to the docker-compose.yml file, both of which are set to true. This corresponds to the -i and -t options of docker run.

3. Run the container using docker-compose:

First, go to the directory where docker-compose.yml is located on the command line. Next, start the service using the following command:

docker-compose up --build

docker-compose up starts the service.
The –build parameter ensures that the service’s image is built or rebuilt before running the service.

4. Question

-What should I do?
Because stdin_open: true tty: true was added to docker-compose.yml, but it still cannot be started. You can
only use docker run -it image name, which is used for the time being.

5. Delete unnecessary images and containers

# 查看容器
docker ps -a
# 停止容器
docker stop ID
# 删除容器
docker rm ID
# 查看镜像
docker images
# 删除镜像
docker rmi ID  # 但是可能两个images有相同的ID
docker rmi name:V1