Docker

DockerFile build run 单个容器的手动操作

微服务 微服务之间的依赖关系

Docker Compose 轻松高效地管理容器，定义运行多个容器

官方介绍

定义，操作多个容器

YAML file配置文件

single command 命令有哪些

Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a YAML file to configure your application’s services. Then, with a single command, you create and start all the services from your configuration. To learn more about all the features of Compose, see the list of features.

所有环境都可以使用Compose

Compose works in all environments: production, staging, development, testing, as well as CI workflows. You can learn more about each case in Common Use Cases.

三步骤

Using Compose is basically a three-step process:

1. Define your app’s environment with a Dockerfile so it can be reproduced anywhere.
   • Dockerfile`确保我们的项目能够在任何地方运行
2. Define the services that make up your app in docker-compose.yml so they can be run together in an isolated environment.
   • Services 什么是服务
   • docker-compose.yml 怎么写
3. Run docker compose up and the Docker compose command starts and runs your entire app. You can alternatively run docker-compose up using the docker-compose binary.
   • 启动项目

功能：批量容器布置

Compose 是Docker需要安装官方开源项目

Dockerfile 让程序在任何地方运行，web服务，mysql，redis…多个容器

Compose

version: "3.9"  # optional since v1.27.0 services:   web:     build: .     ports:       - "8000:5000"     volumes:       - .:/code       - logvolume01:/var/log     links:       - redis   redis:     image: redis volumes:   logvolume01: { 
        } 

Compose：重要概念

• 服务services，容器，应用，（web，redis，mysql…）
• 项目project，一组相关容器

1.下载

 sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose   # 速度快一点  curl -L https://get.daocloud.io/docker/compose/releases/download/1.25.5/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose  

[外链片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-yNyBa3bT-1658059434812)(Docker进阶.assets/1657939654808.png)]

2.授权

sudo chmod +x /usr/local/bin/docker-compose
# 或者
sudo chmod +x docker-compose

# 运行 
docker-compose version
[root@root bin]# docker-compose version
docker-compose version 1.25.5, build 8a1c60f6 # 看到版本号代表安装成功
docker-py version: 4.1.0
CPython version: 3.7.5
OpenSSL version: OpenSSL 1.1.0l  10 Sep 2019

官方文档： Get started with Docker Compose | Docker Documentation

创建文件夹

mkdir composetest
cd composetest

创建 app.py 文件

vim app.py

# 写入内容
import time

import redis
from flask import Flask

app = Flask(__name__)
cache = redis.Redis(host='redis', port=6379)

def get_hit_count():
    retries = 5
    while True:
        try:
            return cache.incr('hits')
        except redis.exceptions.ConnectionError as exc:
            if retries == 0:
                raise exc
            retries -= 1
            time.sleep(0.5)

@app.route('/')
def hello():
    count = get_hit_count()
    return 'Hello World! I have been seen {} times.\n'.format(count)

创建 requirements.txt 文件

vim requirements.txt

# 写入
flask
redis

创建 Dockerfile 文件

vim Dockerfile

# 写入
FROM python:3.7-alpine
WORKDIR /code
ENV FLASK_APP=app.py
ENV FLASK_RUN_HOST=0.0.0.0
RUN apk add --no-cache gcc musl-dev linux-headers
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
EXPOSE 5000
COPY . .
CMD ["flask", "run"]

定义 docker-compose.yml 文件

vim docker-compose.yml

# 写入
version: "3.9"
services:
  web:
    build: .
    ports:
      - "8000:5000"
  redis:
    image: "redis:alpine"

运行

docker compose up

# 或者
docker-compose up

总结：分为4步

1、应用 app.py

2、Dockerfile 应用打包为镜像

3、Docker-compose.yaml 文件（定义整个服务，需要的环境，web，redis）完整的上线服务

4、启动compose项目（docker-compose up）

流程：

1、创建网络

2、执行Docker-compose.yaml

3、启动服务

Docker-compose.yaml

Compose composetest_web_1 …done

Compose composetest_redis_1 …done

1、文件名composetest

2、服务

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-Sd7VbbHV-1658059434814)(Docker进阶.assets/1657955621172.png)]

version: "3.9"
services:
  web:
    build: .
    ports:
      - "8000:5000"
  redis:
    image: "redis:alpine"

自动的默认规则？

docker images

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-aoqs0ulE-1658059434814)(Docker进阶.assets/1657956417713.png)]

默认的服务名 文件名_服务名 _num

多个服务器。集群。A B_num副本数量

服务redis服务略=>4个副本。

集群状态。服务都不可能只有一个运行实例。弹性.10 HA高并发。

（k8s中）kubectl service负载均衡。

3、网络规则

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-ZV9oaAFw-1658059434815)(Docker进阶.assets/1657964566260.png)]

10个服务=>项目 （项目中的内容都在同一个网络下，域名访问）

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-RjPSHevH-1658059434815)(Docker进阶.assets/1657964686084.png)]

停止：

docker compose down 
# 或 ctrl+c

docker-compose 以前都是单个docker run启动容器。 docker-compose。通过 docker-compose编写yaml配置文件、可以通过compose一键启动所有服务，停止。!

小结

1、Docker镜像。run =>容器

2、DockerFile构建镜像（服务打包) 3、docker-compose启动项目(编排、多个微服务/环境)4、Docker网络!

docker-compose.yaml 核心

官方地址： Compose specification | Docker Documentation

# 总共三层

version: '' # 版本
services:  #服务
	服务1: web
		# 服务配置
		images:
		port:
		network: 
		depends_on: # 启动依赖（顺序）
		...
	服务2: redis
		...
# 其他配置 网络、卷、全局规则
volumes: 
network: 

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-3ZF7fdWu-1658059434816)(Docker进阶.assets/1657965844691.png)]

services:
  db:
    image: mariadb:10.6.4-focal
    command: '--default-authentication-plugin=mysql_native_password'
    volumes:
      - db_data:/var/lib/mysql
    restart: always
    environment:
      - MYSQL_ROOT_PASSWORD=somewordpress
      - MYSQL_DATABASE=wordpress
      - MYSQL_USER=wordpress
      - MYSQL_PASSWORD=wordpress
    expose:
      - 3306
      - 33060
  wordpress:
    image: wordpress:latest
    ports:
      - 80:80
    restart: always
    environment:
      - WORDPRESS_DB_HOST=db
      - WORDPRESS_DB_USER=wordpress
      - WORDPRESS_DB_PASSWORD=wordpress
      - WORDPRESS_DB_NAME=wordpress
volumes:
  db_data:

1、编写项目微服务

2、dockerfile构建镜像 3.docker-compose.yaml 编排项目

4、丢到服务器docker-compose up

小结: 未来项目只要有docker-compose文件。按照这个规则，启动编排容器。!

公司: docker-compose。直接启动。 网上开源项目: docker-compose一键搞定。

假设项目要重新部署打包

docker-compose --build # 重新构建
# 或
docker compose --build

总结: 工程、服务、容器项目

compose:三层·工程 Porject·服务服务 容器运行实例! docker k8s容器

官网地址

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-ehCgRAUL-1658059434816)(Docker进阶.assets/1658048039422.png)]

Estimated reading time: 2 minutes

Docker Engine 1.12 introduces swarm mode that enables you to create a cluster of one or more Docker Engines called a swarm. A swarm consists of one or more nodes: physical or virtual machines running Docker Engine 1.12 or later in swarm mode.

There are two types of nodes: managers and workers.

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-EyRMnsVU-1658059434816)(Docker进阶.assets/1658048345555.png)]

If you haven’t already, read through the swarm mode overview and key concepts.

查看命令

假设一个节点挂了！其他节点是否可以用

Raft协议：保证大多数存活才可以用，只要>1，集群至少大于3台

实验：

1.将docker1停止，（宕机）双主，另外一个主节点也不能使用了

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-hHU4l1uF-1658059434817)(Docker进阶.assets/1658050967539.png)]

2.可以将其他节点移开

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-nH20BuKC-1658059434818)(Docker进阶.assets/1658051016360.png)]

3.work就是工作的、管理节点操作!

十分简单:集群，可用!3个主节点。>1台管理节点存活!

Raft协议:保证大多数节点存活，才可以使用，高可用!

弹性。扩缩容，集群！

以后告别docker run! docker-compose up!启动一个项目。单机!

集群: swarm docker serivce 容器=→>服务! 容器=>服务!>副本! redis 服务=>10个副本!(同时开启10个redis容器)

docker service 命令

[root@root liapp]# docker service --help

Usage:  docker service COMMAND

Manage services

Commands:
  create      Create a new service
  inspect     Display detailed information on one or more services
  logs        Fetch the logs of a service or task
  ls          List services
  ps          List the tasks of one or more services
  rm          Remove one or more services
  rollback    Revert changes to a service's configuration scale Scale one or multiple replicated services update Update a service Run 'docker service COMMAND --help' for more information on a command.

创建后跟的参数

[root@root liapp]# docker service create --help

Usage:  docker service create [OPTIONS] IMAGE [COMMAND] [ARG...]

Create a new service

Options:
      --cap-add list                       Add Linux capabilities
      --cap-drop list                      Drop Linux capabilities
      --config config                      Specify configurations to expose
                                           to the service
      --constraint list                    Placement constraints
      --container-label list               Container labels
      --credential-spec credential-spec    Credential spec for managed
                                           service account (Windows only)
  -d, --detach                             Exit immediately instead of
                                           waiting for the service to converge
      --dns list                           Set custom DNS servers
      --dns-option list                    Set DNS options
      --dns-search list                    Set custom DNS search domains
      --endpoint-mode string               Endpoint mode (vip or dnsrr)
                                           (default "vip")
      --entrypoint command                 Overwrite the default ENTRYPOINT
                                           of the image
  -e, --env list                           Set environment variables
      --env-file list                      Read in a file of environment
                                           variables
      --generic-resource list              User defined resources
      --group list                         Set one or more supplementary
                                           user groups for the container
      --health-cmd string                  Command to run to check health
      --health-interval duration           Time between running the check
                                           (ms|s|m|h)
      --health-retries int                 Consecutive failures needed to
                                           report unhealthy
      --health-start-period duration       Start period for the container to
                                           initialize before counting
                                           retries towards unstable (ms|s|m|h)
      --health-timeout duration            Maximum time to allow one check
                                           to run (ms|s|m|h)
      --host list                          Set one or more custom host-to-IP
                                           mappings (host:ip)
      --hostname string                    Container hostname
      --init                               Use an init inside each service
                                           container to forward signals and
                                           reap processes
      --isolation string                   Service container isolation mode
  -l, --label list                         Service labels
      --limit-cpu decimal                  Limit CPUs
      --limit-memory bytes                 Limit Memory
      --limit-pids int                     Limit maximum number of processes
                                           (default 0 = unlimited)
      --log-driver string                  Logging driver for service
      --log-opt list                       Logging driver options
      --max-concurrent uint                Number of job tasks to run
                                           concurrently (default equal to
                                           --replicas)
      --mode string                        Service mode (replicated, global,
                                           replicated-job, or global-job)
                                           (default "replicated")
      --mount mount                        Attach a filesystem mount to the
                                           service
      --name string                        Service name
      --network network                    Network attachments
      --no-healthcheck                     Disable any container-specified
                                           HEALTHCHECK
      --no-resolve-image                   Do not query the registry to
                                           resolve image digest and
                                           supported platforms
      --placement-pref pref                Add a placement preference
  -p, --publish port                       Publish a port as a node port
  -q, --quiet                              Suppress progress output
      --read-only                          Mount the container's root
                                           filesystem as read only
      --replicas uint                      Number of tasks
      --replicas-max-per-node uint         Maximum number of tasks per node
                                           (default 0 = unlimited)
      --reserve-cpu decimal                Reserve CPUs
      --reserve-memory bytes               Reserve Memory
      --restart-condition string           Restart when condition is met
                                           ("none"|"on-failure"|"any")
                                           (default "any")
      --restart-delay duration             Delay between restart attempts
                                           (ns|us|ms|s|m|h) (default 5s)
      --restart-max-attempts uint          Maximum number of restarts before
                                           giving up
      --restart-window duration            Window used to evaluate the
                                           restart policy (ns|us|ms|s|m|h)
      --rollback-delay duration            Delay between task rollbacks
                                           (ns|us|ms|s|m|h) (default 0s)
      --rollback-failure-action string     Action on rollback failure
                                           ("pause"|"continue") (default "pause")
      --rollback-max-failure-ratio float   Failure rate to tolerate during a
                                           rollback (default 0)
      --rollback-monitor duration          Duration after each task rollback
                                           to monitor for failure
                                           (ns|us|ms|s|m|h) (default 5s)
      --rollback-order string              Rollback order
                                           ("start-first"|"stop-first")
                                           (default "stop-first")
      --rollback-parallelism uint          Maximum number of tasks rolled
                                           back simultaneously (0 to roll
                                           back all at once) (default 1)
      --secret secret                      Specify secrets to expose to the
                                           service
      --stop-grace-period duration         Time to wait before force killing
                                           a container (ns|us|ms|s|m|h)
                                           (default 10s)
      --stop-signal string                 Signal to stop the container
      --sysctl list                        Sysctl options
  -t, --tty                                Allocate a pseudo-TTY
      --ulimit ulimit                      Ulimit options (default [])
      --update-delay duration              Delay between updates
                                           (ns|us|ms|s|m|h) (default 0s)
      --update-failure-action string       Action on update failure
                                           ("pause"|"continue"|"rollback")
                                           (default "pause")
      --update-max-failure-ratio float     Failure rate to tolerate during
                                           an update (default 0)
      --update-monitor duration            Duration after each task update
                                           to monitor for failure
                                           (ns|us|ms|s|m|h) (default 5s)
      --update-order string                Update order
                                           ("start-first"|"stop-first")
                                           (default "stop-first")
      --update-parallelism uint            Maximum number of tasks updated
                                           simultaneously (0 to update all
                                           at once) (default 1)
  -u, --user string                        Username or UID (format:
                                           <name|uid>[:<group|gid>])
      --with-registry-auth                 Send registry authentication
                                           details to swarm agents
  -w, --workdir string                     Working directory inside the container

docker run     # 容器启动！不具有扩缩容容器
docker service # 服务！ 具有扩缩容，滚动更新

扩缩容

# 扩展三个副本
docker service update --replicas 3 my-nginx

服务。集群中任意的节点都可以访问。服务可以有多个副本动态扩缩容实现高可用!

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-nemmixSI-1658059434819)(Docker进阶.assets/1658056812315.png)]

也可以用scale进行扩缩容

docker service scale my-nginx=3           # 扩展三份

可以通过rm移除服务

docker service rm my-nginx

swarm

集群的管理和编号。docker可以初始化一个swarm集群，其他节点可以加入。(管理、工作者)

Node 就是一个docker节点。多个节点就组成了一个网络集群。(管理、工作者)

service 任务，可以在管理节点或者工作节点来运行。核心。!用户访问!

Task 客器内的命令，细节任务!

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-6JQFSVUW-1658059434819)(Docker进阶.assets/1658058602191.png)]

逻辑是不变的

命令->管理-> api ->调度->工作节点(创建Task容器维护创建!)