Docker

docker基础教程，Docker 使您能够将应用程序与基础架构分开,从而可以快速交付软件。借助 Docker,您可以与管理应用程序相同的方式来管理基础架构。通过利用 Docker 的方法来快速交付,测试和

Docker

• 基础控制/配置
  • docker run -d -p 80:80 docker/getting-started
    • -d
      • run the container in detached mode (in the background)
    • -p 80:80
      • map port 80 of the host to port 80 in the container
    • docker/getting-started
      • the image to use
  • docker build -t getting-started .
    • go to the app directory with the Dockerfile and using the docker build command.
    • Dockerfile
      • FROM node:12-alpine # Adding build tools to make yarn install work on Apple silicon / arm64 machines RUN apk add --no-cache python2 g++ make WORKDIR /app COPY . . RUN yarn install --production CMD ["node", "src/index.js"]
        • we wanted to start from the node:12-alpine image. But, since we didn't have that on our machine, that image needed to be downloaded.
        • we copied in our application and used yarn to install our application's dependencies. The CMD directive specifies the default command to run when starting a container from this image
      • a text-based script of instructions that is used to create a container image
    • -t flag tags our image.
    • . tells that Docker should look for the Dockerfile in the current directory.
    • Updating our Source
      • rebuild
  • docker ps
    • Get the ID of the container
  • docker stop <the-container-id>
    • stop the container
  • docker rm <the-container-id>
    • remove a container
  • docker rm -f <the-container-id>
    • stop and remove a container in a single command by adding the "force" flag
  • docker run -d ubuntu bash -c "shuf -i 1-10000 -n 1 -o /data.txt && tail -f /dev/null"
    • starting a bash shell
      • picks a single random number and writes it to /data.txt
      • watching a file to keep the container running
  • docker exec <container-id> cat /data.txt
    • 查看对应容器data文档生成情况
• 镜像发布
  • docker login -u YOUR-USER-NAME
    • Login to the Docker Hub
  • docker tag getting-started YOUR-USER-NAME/getting-started
    • give the getting-started image a new name
  • docker push YOUR-USER-NAME/getting-started
  • docker run -dp 3000:3000 YOUR-USER-NAME/getting-started
• 数据持久化
  • Named Volumes
    • docker volume create todo-db
      • Create a named volume
    • docker run -dp 3000:3000 -v todo-db:/etc/todos getting-started
  • Bind Mounts
    • docker run -dp 3000:3000 \ -w /app -v "$(pwd):/app" \ node:12-alpine \ sh -c "yarn install && yarn run dev"
      • MAC系统指令
        • docker run -dp 3000:3000 \ -w /app -v "$(pwd):/app" \ node:12-alpine \ sh -c "apk add --no-cache python2 g++ make && yarn install && yarn run dev"
    • -w /app - sets the container's present working directory where the command will run from
    • -v "$(pwd):/app" - bind mount (link) the host's present getting-started/app directory to the container's /app directory. Note: Docker requires absolute paths for binding mounts, so in this example we use pwd for printing the absolute path of the working directory
    • node:12-alpine - the image to use. Note that this is the base image for our app from the Dockerfile
    • sh -c "yarn install && yarn run dev" - the command. We're starting a shell using sh (alpine doesn't have bash) and running yarn install to install all dependencies and then running yarn run dev
  • Comparisons
• 容器连接
  • Create network
    • docker network create todo-app
  • Start a MySQL
    • docker run -d \ --network todo-app --network-alias mysql \ -v todo-mysql-data:/var/lib/mysql \ -e MYSQL_ROOT_PASSWORD=secret \ -e MYSQL_DATABASE=todos \ mysql:5.7
      • docker run -d \ --network todo-app --network-alias mysql --platform linux/amd64\ -v todo-mysql-data:/var/lib/mysql \ -e MYSQL_ROOT_PASSWORD=secret \ -e MYSQL_DATABASE=todos \ mysql:5.7
  • verify it connects
    • docker exec -it <mysql-container-id> mysql -p
  • Connecting to MySQL
    • nicolaka/netshoot
      • for troubleshooting or debugging networking issues
      • docker run -it --network todo-app nicolaka/netshoot
        • dig mysql
  • connect the container
    • docker run -dp 3000:3000 \ -w /app -v "$(pwd):/app" \ --network todo-app \ -e MYSQL_HOST=mysql \ -e MYSQL_USER=root \ -e MYSQL_PASSWORD=secret \ -e MYSQL_DB=todos \ node:12-alpine \ sh -c "yarn install && yarn run dev"
      • docker run -dp 3000:3000 \ -w /app -v "$(pwd):/app" \ --network todo-app \ -e MYSQL_HOST=mysql \ -e MYSQL_USER=root \ -e MYSQL_PASSWORD=secret \ -e MYSQL_DB=todos \ node:12-alpine \ sh -c "apk --no-cache --virtual build-dependencies add python2 make g++ && yarn install && yarn run dev"
• 容器组合
  • Creating Compose File
    • docker-compose.yml
      • version: "3.8" services: app: image: node:12-alpine command: sh -c "yarn install && yarn run dev" ports: - 3000:3000 working_dir: /app volumes: - ./:/app environment: MYSQL_HOST: mysql MYSQL_USER: root MYSQL_PASSWORD: secret MYSQL_DB: todos mysql: image: mysql:5.7 volumes: - todo-mysql-data:/var/lib/mysql environment: MYSQL_ROOT_PASSWORD: secret MYSQL_DATABASE: todos volumes: todo-mysql-data:
  • docker-compose up -d
  • docker-compose logs -f
    • -f flag "follows"
  • docker-compose down
• 实践
  • Security Scanning
    • docker scan getting-started
  • Image Layering
    • docker image history getting-started
  • Layer Caching
    • using the build cache
    • FROM node:12-alpine # Adding build tools to make yarn install work on Apple silicon / arm64 machines RUN apk add --no-cache python2 g++ make WORKDIR /app COPY . . RUN yarn install --production CMD ["node", "src/index.js"]
    • FROM node:12-alpine # Adding build tools to make yarn install work on Apple silicon / arm64 machines RUN apk add --no-cache python2 g++ make WORKDIR /app COPY package.json yarn.lock ./ RUN yarn install --production COPY . . CMD ["node", "src/index.js"]
  • Multi-Stage Builds
    • Separate build-time dependencies from runtime dependencies
    • Reduce overall image size by shipping only what your app needs to run