Docker深刻浅出系列 | Docker Compose多容器实战

时间 2020-04-24

标签 docker 深刻系列 compose 容器实战栏目 Docker 繁體版

原文原文链接

[TOC]html

Docker已经上市不少年，不是什么新鲜事物了，不少企业或者开发同窗之前也很少很多有所接触，可是有实操经验的人很少，本系列教程主要偏重实战，尽可能讲干货，会根据本人理解去作阐述，具体官方概念能够查阅官方教程，由于本系列教程对前一章节有必定依赖，建议先学习前面章节内容。java

教程目的：nginx

了解docker-compose是什么&为何要用
了解docker-compose如何安装
了解如何建立docker-compose 文件
了解如何利用docker-compose 文件去建立服务
了解docker compose的基本命令
了解如何经过docker compose进行弹性扩容
掌握docker-compose在nginx+springboot实战应用

前期准备

1.下载mysqlgit

docker pull mysql

2.下载nginxgithub

docker pull nginx

3.克隆credit-facility-service做为后面部署演示使用，使用docker分支web

git clone https://github.com/EvanLeung08/credit-facility-service.git

4.虚拟机、centos和docker环境安装请查看第一章，本章默认已经安装好centos和docker Docker深刻浅出系列 | 容器初体验spring

Docker Compose是什么

Docker Compose是一个用于定义和运行多容器应用程序的工具。经过compose，咱们可使用yaml文件来配置应用程序的服务，而后使用一个命令来建立和启动全部已配置的服务。在微服务环境中进行本地开发测试时，咱们常用此工具。它也是轻量级的，只须要简单的配置。您能够预先配置所需的环境和服务，而后专一于当前开发的服务，而没必要管理开发时如何运行每一个服务的方式。 sql

为何要用Docker Compose

首先，咱们回顾前一章，咱们要部署一个微服务项目，须要手动配置一堆命令，十分繁琐，假若有几十上百个容器，而且容器之间还存在依赖，光是忙着搭建容器都耗掉一天了，还谈什么Devops，那有没有什么方便快捷的组建，可让咱们经过一个配置就搞定容器编排和运行呢？docker

Docker compose就是为了简化多容器配置和管理工做而生的，能够简化大量重复的手动工做，具备如下主要特色：

提供工具用于定义和运行多个docker容器应用
使用yaml文件来配置应用服务(docker-compse.yml)
能够经过一个简单的命令docker-compse up能够按照依赖关系启动全部服务
能够经过一个简单的命令docker-compose down中止全部服务
当一个服务须要的时候，能够很简单地经过--scale进行扩容

Docker Compose的考虑理由:

可移植性： Docker Compose仅需一个命令便可提供完整的开发环境：docker-compose up，而后使用docker-compose down轻松将其拆解。这使咱们的开发人员能够将开发环境保持在一个中立位置，并帮助咱们轻松地部署应用程序。
测试： Compose的另外一个重要功能是经过将其置于本身的环境中，以快速可重复的方式支持运行单元和E2E测试。这意味着，您能够运行与生产环境很是类似的环境，而不是在本地/主机系统上测试应用程序。
单个主机上的多个隔离环境： Compose使用项目名称将环境彼此隔离，这带来了如下好处：
- 您能够在一台计算机上运行同一环境的多个副本
- 它能够防止不一样的项目和服务相互干扰

Docker Compose使用场景

单主机部署：传统上，Compose专一于开发和测试，但如今可用于在单个主机系统上进行部署和管理容器的整个部署过程。
开发环境： Compose提供了在孤立的环境中运行应用程序的能力，该环境能够在安装了Docker的任何计算机上运行。这使测试你的应用程序变得很是容易，并提供了一种尽量接近生产环境的工做方式。 Compose文件管理应用程序的全部依赖项（数据库，队列，缓存等），而且可使用单个命令建立每一个容器。
自动化测试环境：持续集成和整个开发过程的重要组成部分是自动化测试套件，该套件要求能够在其中执行测试的环境。 Compose提供了一种方便的方法来建立和销毁与您的生产环境接近的隔离测试环境。

Docker Compose安装

能够参考官网:Docker Compose安装

1.下载当前稳定版本，选择对应系统版本，我这里用的是Centos

经过官方下载

sudo curl -L "https://github.com/docker/compose/releases/download/1.25.4/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

经过国内源下载

sudo curl -L https://get.daocloud.io/docker/compose/releases/download/1.25.0/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose

2.赋予可执行权限

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

Compose Yaml文件结构

经过Compose，咱们开发人员能够经过应用在docker-compose.yml文件中声明的许多规则轻松地一次处理多个Docker容器。

它由多个层级组成，这些层级使用制表符或空格分隔，而不是大多数编程语言中已知的括号。几乎每一个Compose-File应该具备如下四个主要方面：

Compose文件的Version
咱们将要构建的Services
全部要使用的Volumes
用来链接不一样服务的network

docker-compose.yml 示例:

version: '3.3'

services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress

   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8000:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
       WORDPRESS_DB_NAME: wordpress
volumes:
    db_data: {}

以上文件包含整个Wordpress应用程序，包括MySQL数据库。这些服务中的每个都被视为一个单独的容器，能够在须要时进行添加或删除

我是怎么知道这些命令怎么使用? 详细的配置参数，能够查阅: 官方配置参数

Compose 基本操做命令

查看docker-compose的基本操做命令，能够经过docker-compose --help进行查看，不少命令实际上是跟docker类似

[root@localhost credit-facility]# docker-compose --help
Define and run multi-container applications with Docker.

Usage:
  docker-compose [-f <arg>...] [options] [COMMAND] [ARGS...]
  docker-compose -h|--help

Options:
  -f, --file FILE             Specify an alternate compose file
                              (default: docker-compose.yml)
  -p, --project-name NAME     Specify an alternate project name
                              (default: directory name)
  --verbose                   Show more output
  --log-level LEVEL           Set log level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
  --no-ansi                   Do not print ANSI control characters
  -v, --version               Print version and exit
  -H, --host HOST             Daemon socket to connect to

  --tls                       Use TLS; implied by --tlsverify
  --tlscacert CA_PATH         Trust certs signed only by this CA
  --tlscert CLIENT_CERT_PATH  Path to TLS certificate file
  --tlskey TLS_KEY_PATH       Path to TLS key file
  --tlsverify                 Use TLS and verify the remote
  --skip-hostname-check       Don't check the daemon's hostname against the
                              name specified in the client certificate
  --project-directory PATH    Specify an alternate working directory
                              (default: the path of the Compose file)
  --compatibility             If set, Compose will attempt to convert keys
                              in v3 files to their non-Swarm equivalent
  --env-file PATH             Specify an alternate environment file

Commands:
  build              Build or rebuild services
  bundle             Generate a Docker bundle from the Compose file
  config             Validate and view the Compose file
  create             Create services
  down               Stop and remove containers, networks, images, and volumes
  events             Receive real time events from containers
  exec               Execute a command in a running container
  help               Get help on a command
  images             List images
  kill               Kill containers
  logs               View output from containers
  pause              Pause services
  port               Print the public port for a port binding
  ps                 List containers
  pull               Pull service images
  push               Push service images
  restart            Restart services
  rm                 Remove stopped containers
  run                Run a one-off command
  scale              Set number of containers for a service
  start              Start services
  stop               Stop services
  top                Display the running processes
  unpause            Unpause services
  up                 Create and start containers
  version            Show the Docker-Compose version information

Docker Compose实战

相信你们都已经看过上一章，若是你们尚未看过，请先回到上一章节教程。

在上一章，咱们经过手动方式，一步步搭建了Nginx、Mysql以及额度服务，相信你们都体会到整个流程很是繁琐，有一部出错了，都要从新敲一遍指令，在本章咱们沿用上一章的环境配置，可是整个过程会经过docker compose来帮咱们自动部署而不是手动部署。

实战目标

建立docker网络，设置静态子网ip168.18.0.0/24
搭建额度服务集群
- [额度服务]credit-facility01 - 168.18.0.10
- [额度服务]credit-facility02 - 168.18.0.11
- [额度服务]credit-facility03 - 168.18.0.12
搭建Mysql数据库
- [Mysql服务]credit-facility-db - 168.18.0.4
搭建Nginx服务，并配置负载均衡规则
- [Nginx服务]credit-facility-nginx - 168.18.0.5
建立Volume credit-facility-volume，用于持久化Mysql容器数据
利用docker内置DNS服务器的特色，docker网络内容器之间经过容器名称进行通讯
经过浏览器访问swagger进行业务操做

实战步骤

清理旧配置

1.若是上一章已经建立好了容器，先清理上一章已经建立的容器，避免冲突

docker container stop credit-facility01
docker container stop credit-facility02
docker container stop credit-facility03
docker container stop credit-facility-db
docker container stop credit-facility-nginx
docker container rm credit-facility01
docker container rm credit-facility02
docker container rm credit-facility03
docker container rm credit-facility-db
docker container rm credit-facility-nginx

2.清理上一章建立好的网络credit-facility-net

docker network rm credit-facility-net

3.核对下当前Centos系统上credit-facility目录下的文件是否跟我一致，若是不同，请先查看上一章

[root@localhost credit-facility]# ls
Dockerfile nginx  start-1.0.0-SNAPSHOT.jar

咱们上一章建立好的文件应该是以上三个

搭建环境

1.上传credit-facility-service项目里的docker-compose.yml文件到Centos系统credit-facility目录下，若是还没克隆额度服务到本地，请查看前期准备

docker-compose.yml文件存放在credit-facility-service项目dockerfile目录下

[root@localhost credit-facility]# ls
Dockerfile  docker-compose.yml  nginx  start-1.0.0-SNAPSHOT.jar

这时候会多了一个docker-compose.yml文件

PS: 若是在前面章节没有建立额度服务镜像，这里须要先建立credit-facility-image镜像:

[root@localhost credit-facility]# docker build -t credit-facility-image .

2.经过docker config校验compose文件，若是文件格式有问题，经过该命令能够帮你校验并输出错误信息

[root@localhost credit-facility]# docker-compose config
networks:
  credit-facility-net:
    driver: bridge
    ipam:
      config:
      - subnet: 168.18.0.0/24
services:
  credit-facility-service1:
    build:
      context: /usr/local/credit-facility
    container_name: credit-facility01
    image: credit-facility-image
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.10
    ports:
    - 8081:8080/tcp
    restart: always
  credit-facility-service2:
    build:
      context: /usr/local/credit-facility
    container_name: credit-facility02
    image: credit-facility-image
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.11
    ports:
    - 8082:8080/tcp
    restart: always
  credit-facility-service3:
    build:
      context: /usr/local/credit-facility
    container_name: credit-facility03
    image: credit-facility-image
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.12
    ports:
    - 8083:8080/tcp
    restart: always
  mysql:
    build:
      context: /usr/local/credit-facility
    container_name: credit-facility-db
    environment:
      MYSQL_DATABASE: db_credit_facility
      MYSQL_ROOT_PASSWORD: evan123
    image: mysql
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.4
    ports:
    - 3301:3306/tcp
    restart: always
    volumes:
    - credit-facility-volume:/var/lib/mysql:rw
  nginx:
    build:
      context: /usr/local/credit-facility
    container_name: credit-facility-nginx
    image: nginx
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.5
    ports:
    - 80:80/tcp
    restart: always
    volumes:
    - /usr/local/credit-facility/nginx/nginx.conf:/etc/nginx/nginx.conf:rw
version: '3.0'
volumes:
  credit-facility-volume: {}

这里能够看到，咱们的配置文件检验经过，接下来咱们分段拆解来讲明下每一段脚本的意思

配置网络

networks:
  credit-facility-net:
    driver: bridge
    ipam:
      config:
      - subnet: 168.18.0.0/24

跟前面同样，这里建立了一个自定义网络credit-facility-net，指定了docker的网络模式是bridge，划分了一个子网ip段168.18.0.0/24，跟前一章手动配置对应的命令以下:

[root@localhost ~]# docker network create --subnet=168.18.0.0/24 credit-facility-net

配置Mysql容器

mysql:
    restart: always
    container_name: credit-facility-db
    image: mysql
    ports:
      - "3301:3306"
    volumes:
      - "credit-facility-volume:/var/lib/mysql:rw"
    environment:
      - MYSQL_DATABASE=db_credit_facility
      - MYSQL_ROOT_PASSWORD=evan123
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.4

restart - 指定了容器每次部署都会从新重启
container_name - 指定了容器名称为credit-facility-db
image - 指定了咱们用来运行容器的镜像是mysql，若是指定的image不存在，它会自动从远程仓库下载
ports - 指定了咱们映射端口，这里把容器3306端口映射到宿主机器3301端口
volumes - 指定了容器里的存储路径以volume挂载方式映射到宿主机器上credit-facility-volume，而且分配读写权限
environment - 这里环境变量的做用是向容器传递参数，指定了数据库实例为db_credit_facility，数据库root用户密码为evan123
networks - 指定了网络选用自定义网络credit-facility-net,分配静态IP 168.18.0.4

上面的compose文件配置对应前一章的手动配置命令以下:

[root@localhost ~]# docker run -d --name credit-facility-db -v credit-facility-volume:/var/lib/mysql -p 3301:3306 -e MYSQL_ROOT_PASSWORD=evan123 --net=credit-facility-net --ip 168.18.0.4 mysql

配置额度服务集群

credit-facility-service1:
    restart: always
    container_name: credit-facility01
    depends_on:
      - mysql
    image: credit-facility-image
    build: .
    ports:
      - "8081:8080"
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.10


  credit-facility-service2:
    restart: always
    container_name: credit-facility02
    depends_on:
      - mysql
    image: credit-facility-image
    build: .
    ports:
      - "8082:8080"
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.11

  credit-facility-service3:
    restart: always
    container_name: credit-facility03
    depends_on:
      - mysql
    image: credit-facility-image
    build: .
    ports:
      - "8083:8080"
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.12

核心配置:

container_name - 这里主要是配置3个额度服务实例，分别为credit-facility01、credit-facility02和credit-facility03
build - 这里指定了docker-compose从当前目录寻找dockerfile文件进行镜像建立和启动容器
depends_on - 它指定当前容器依赖mysql容器，这样子docker-compose启动时会按照依赖关系来启动
networks - 指定了自定义网络credit-facility-net，并对三个实例分别分配了静态ip168.18.0.10、168.18.0.11和168.18.0.12

大部分命令跟前面同样，因此这里不做重复讲解。这里对应前一章的手动配置命令以下:

[root@localhost credit-facility]# docker build -t credit-facility-image .
[root@localhost credit-facility]# docker run -d --name credit-facility01 -p 8081:8080  --net=credit-facility-net --ip 168.18.0.10 credit-facility-image
[root@localhost credit-facility]# docker run -d --name credit-facility02 -p 8082:8080  --net=credit-facility-net --ip 168.18.0.11 credit-facility-image
[root@localhost credit-facility]# docker run -d --name credit-facility03 -p 8083:8080  --net=credit-facility-net --ip 168.18.0.12 credit-facility-image

这里沿用上一章在credit-facility目录下建立的dockerfile：

FROM openjdk:8-jre-alpine
MAINTAINER evan
LABEL name="credit-facility" version="1.0" author="evan"
COPY start-1.0.0-SNAPSHOT.jar credit-facility-service.jar
CMD ["java","-jar","credit-facility-service.jar"]

配置Nginx服务

nginx:
    restart: always
    container_name: credit-facility-nginx
    depends_on:
      - mysql
      - credit-facility-service1
      - credit-facility-service2
      - credit-facility-service3
    image: nginx
    ports:
      - "80:80"
    volumes:
      - /usr/local/credit-facility/nginx/nginx.conf:/etc/nginx/nginx.conf
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.5

核心配置：

container_name - 把nginx容器命名为credit-facility-nginx
depends_on - 定义了容器启动依赖关系
ports - 把容器80端口映射到宿主机80端口
volumes - 把容器目录下的/etc/nginx/nginx.conf 文件映射到宿主机/usr/local/credit-facility/nginx/nginx.conf，这里的nginx配置沿用上一章的配置不变，宿主机的配置会自动覆盖容器的nginx.conf文件
networks - 指定网络为credit-facility-net，并分配静态ip为168.18.0.5

大部分命令跟前面同样，因此这里不做重复讲解。这里对应前一章的手动配置命令以下:

[root@localhost nginx]# docker run -d --name credit-facility-nginx -p 80:80 -v /usr/local/credit-facility/nginx/nginx.conf:/etc/nginx/ningx.conf --network=credit-facility-net --ip 168.18.0.5 nginx

这里沿用上一章的Nginx配置/usr/local/credit-facility/nginx/nginx.conf:

user nginx;
worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;


    server {
        listen 80;
        location / {
         proxy_pass http://balance;
        }
    }

    upstream balance{
       server credit-facility01:8080;
       server credit-facility02:8080 ;
       server credit-facility03:8080;
    }
    include /etc/nginx/conf.d/*.conf;
}

这里是经过容器名称访问，所以不须要管每一个容器的ip是多少

4.经过docker-compose up启动全部服务

[root@localhost credit-facility]# docker-compose up
Creating network "credit-facility_credit-facility-net" with driver "bridge"
Creating credit-facility02     ... done
Creating credit-facility-db    ... done
Creating credit-facility03     ... done
Creating credit-facility-nginx ... done
Creating credit-facility01     ... done
...

经过docker-compose命令，会按照咱们在docker-compose.yml配置的信息去建立和启动服务，而且把日志打印到控制台输出，这里由于日志太多，只截取了部分日志，只要日志没有报错信息，全部服务到这里已经搭建完成

验证环境

1.验证Nginx服务是否已经成功，这里须要经过宿主机ip+映射端口访问

先查看下当前centos机器的ip

[root@localhost credit-facility]# ip add
...
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 08:00:27:ba:0a:28 brd ff:ff:ff:ff:ff:ff
    inet 192.168.101.23/24 brd 192.168.101.255 scope global noprefixroute dynamic eth1
       valid_lft 68553sec preferred_lft 68553sec
    inet6 fe80::a00:27ff:feba:a28/64 scope link 
       valid_lft forever preferred_lft forever

从上面能够看到，宿主机外网ip是192.168.101.23

在本机浏览器输入192.168.101.23进行验证 Nginx服务已经启动成功

2.验证额度服务是否成功访问

经过Nginx 80端口验证

分别经过每一个实例自身映射端口访问

3.验证额度服务接口是否能够处理成功

在验证额度服务前，须要先把表建立好，把credit-facility-service下的db script在DB里执行进入到Mysql容器，把表建立sql放进去执行

[root@localhost credit-facility]# docker exec -it credit-facility-db bash
root@d0d2fb8006c9:/# mysql -uroot -pevan123
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| db_credit_facility |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.01 sec)

mysql> use db_credit_facility;
Database changed
mysql> CREATE TABLE `t_product_limit`
...

输入下面请求数据测试接口

{
	"registrationLimitCO": {
		"applicationId": "1111",
		"userId": 1111,
		"quotaLimit": 10000,
		"productCode": "tb",
		"expirationTime": "2030-01-01",
		"accountType": 1
	}

}

从上面输出结果能够看到，接口已经处理成功

4.进去数据库查看是否已经保存数据成功

mysql> select * from t_product_limit;
+--------------------+---------------------+---------------------+---------+---------+--------------------+--------------------+-------------+---------+--------------+-------------+---------------+-----------------+--------------+------------+--------------+------------+---------------+-------------+---------------+---------------------+---------------+---------------+-----------+-----------+
| id                 | create_time         | edit_time           | deleted | version | serial_number      | account_id         | customer_id | user_id | product_code | quota_limit | quota_balance | quota_occupancy | quota_frozen | quota_base | quota_change | quota_mode | frozen_status | frozen_time | expire_status | expiration_time     | active_status | inactive_time | parent_id | abandoned |
+--------------------+---------------------+---------------------+---------+---------+--------------------+--------------------+-------------+---------+--------------+-------------+---------------+-----------------+--------------+------------+--------------+------------+---------------+-------------+---------------+---------------------+---------------+---------------+-----------+-----------+
| 684437432334159872 | 2020-03-03 08:30:00 | 2020-03-03 08:30:00 |       0 |       0 | 684437432338354177 | 684437432338354176 |      111111 |    1111 | tb           |       10000 |             0 |               0 |            0 |          0 |            0 |       NULL |             1 | NULL        |          NULL | 2030-01-01 00:00:00 |          NULL | NULL          |      NULL |         0 |
+--------------------+---------------------+---------------------+---------+---------+--------------------+--------------------+-------------+---------+--------------+-------------+---------------+-----------------+--------------+------------+--------------+------------+---------------+-------------+---------------+---------------------+---------------+---------------+-----------+-----------+
1 row in set (0.00 sec)

Compose弹性扩容初体验

在互联网公司比较场景，常常会遇到服务器资源不足，特别是遇到节假日公司要搞活动，须要临时扩容增大服务的计算能力，假如咱们公司已经用上docker，docker-compose就能够帮咱们很简单作到服务器扩容，固然，docker-compose不多直接在生产上独立使用，更可能是在开发测试环境，后面讲解k8s的时候会介绍生产上如何作到弹性扩容。接下来，咱们只须要经过简单的命令就能够实现弹性扩容

1.对于前面咱们建立的docker-compose.yml作一点改动，加入一个新的服务定义，以下

web:
    restart: always
    image: credit-facility-image
    build: .
    expose:
      - "8080"
    depends_on:
      - mysql
      - credit-facility-service1
      - credit-facility-service2
      - credit-facility-service3
    networks:
      - credit-facility-net

这里指定了容器端口是8080，可是没有配置宿主机端口映射，网络也加入到credit-facility-net

Nginx也须要调整下，把静态ip去掉，而且加上依赖，避免ip冲突，docker会自动分配一个静态ip

nginx:
    restart: always
    container_name: credit-facility-nginx
    depends_on:
      - mysql
      - credit-facility-service1
      - credit-facility-service2
      - credit-facility-service3
      - web
    image: nginx
    ports:
      - "80:80"
    links:
      - web
    volumes:
      - /usr/local/credit-facility/nginx/nginx.conf:/etc/nginx/nginx.conf
    networks:
      - credit-facility-net

在这里我复制了一份credit-facility-service配置，为了方便演示，我去掉了网络配置和端口映射，由于若是想使用弹性扩容，端口和ip不能固定，不然会启动失败，改造后完整的配置以下:

version: '3'
services:

  mysql:
    restart: always
    container_name: credit-facility-db
    image: mysql
    ports:
      - "3301:3306"
    volumes:
      - "credit-facility-volume:/var/lib/mysql:rw"
    environment:
      - MYSQL_DATABASE=db_credit_facility
      - MYSQL_ROOT_PASSWORD=evan123
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.4

  credit-facility-service1:
    restart: always
    container_name: credit-facility01
    depends_on:
      - mysql
    image: credit-facility-image
    build: .
    ports:
      - "8081:8080"
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.10


  credit-facility-service2:
    restart: always
    container_name: credit-facility02
    depends_on:
      - mysql
    image: credit-facility-image
    build: .
    ports:
      - "8082:8080"
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.11

  credit-facility-service3:
    restart: always
    container_name: credit-facility03
    depends_on:
      - mysql
    image: credit-facility-image
    build: .
    ports:
      - "8083:8080"
    networks:
      credit-facility-net:
        ipv4_address: 168.18.0.12

  web:
    restart: always
    image: credit-facility-image
    build: .
    expose:
      - "8080"
    depends_on:
      - mysql
      - credit-facility-service1
      - credit-facility-service2
      - credit-facility-service3
    networks:
      - credit-facility-net

  nginx:
    restart: always
    container_name: credit-facility-nginx
    depends_on:
      - mysql
      - credit-facility-service1
      - credit-facility-service2
      - credit-facility-service3
      - web
    image: nginx
    ports:
      - "80:80"
    links:
      - web
    volumes:
      - /usr/local/credit-facility/nginx/nginx.conf:/etc/nginx/nginx.conf
    networks:
      - credit-facility-net

networks:
  credit-facility-net:
    driver: bridge
    ipam:
      config:
        - subnet: 168.18.0.0/24
volumes:
  credit-facility-volume: {}

2.执行如下命令，对web服务进行弹性扩容，建立三个容器实例

[root@localhost credit-facility]# docker-compose up --scale web=3 -d
Creating network "credit-facility_credit-facility-net" with driver "bridge"
Creating network "credit-facility_default" with the default driver
Creating credit-facility_web_1 ... done
Creating credit-facility_web_2 ... done
Creating credit-facility_web_3 ... done
Creating credit-facility01     ... done
Creating credit-facility02     ... done
Creating credit-facility03     ... done
Creating credit-facility-nginx ... done
Creating credit-facility-db    ... done

从上图能够看到，web服务对应的容器实例已经建立成功，它的命名方式是基于dockerfile里面的Label名称+_web_<实例序号>。

3.经过docker-compose ps查看下当前已启动的容器

[root@localhost credit-facility]# docker-compose ps
        Name                       Command               State                 Ports              
--------------------------------------------------------------------------------------------------
credit-facility-db      docker-entrypoint.sh mysqld      Up      0.0.0.0:3301->3306/tcp, 33060/tcp
credit-facility-nginx   nginx -g daemon off;             Up      0.0.0.0:80->80/tcp               
credit-facility01       java -jar credit-facility- ...   Up      0.0.0.0:8081->8080/tcp           
credit-facility02       java -jar credit-facility- ...   Up      0.0.0.0:8082->8080/tcp           
credit-facility03       java -jar credit-facility- ...   Up      0.0.0.0:8083->8080/tcp           
credit-facility_web_1   java -jar credit-facility- ...   Up      8080/tcp                         
credit-facility_web_2   java -jar credit-facility- ...   Up      8080/tcp                         
credit-facility_web_3   java -jar credit-facility- ...   Up      8080/tcp

这里能够看到，咱们配置的全部容器都启动成功，而且新增了三个web容器实例

4.经过docker-compose logs web能够查看web服务每一个实例的日志

5.修改下nginx.conf的配置，改成新的web容器名称，注释掉咱们原来的credit-facility容器

user nginx;
worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65; 

   
    server {
        listen 80;
        location / {
         proxy_pass http://balance;
        }
    }
    
    upstream balance{  
      #  server credit-facility01:8080;
      # server credit-facility02:8080 ;
      # server credit-facility03:8080;
      server credit-facility_web_1:8080;
      server credit-facility_web_2:8080;
      server credit-facility_web_3:8080;
    }
    include /etc/nginx/conf.d/*.conf;
}

6.重启nginx服务

[root@localhost nginx]# docker restart credit-facility-nginx 
credit-facility-nginx

7.经过Postman测试WEB服务

请求Url输入你宿主机ip，请求方式是POST，在请求body输入如下请求数据:

{
	"registrationLimitCO": {
		"applicationId": "1111",
		"userId": 1111,
		"quotaLimit": 10000,
		"productCode": "tb",
		"expirationTime": "2030-01-01",
		"accountType": 1
	}

}

从上面相应结果能够看到，服务处理成功

附录

引用

Docker Compose官方文档：官方文档 Demo项目地址：Demo下载

Q&A

1.docker-compose up启动报错

[root@localhost credit-facility]# docker-compose up
ERROR: Named volume "credit-facility-volume:/var/lib/mysql:rw" is used in service "mysql" but no declaration was found in the volumes section.

解决方案： 这是由于缺乏Volume声明，在docker-compose.yml按以下配置(上文的配置文件已经配置好)

- "credit-facility-volume:/var/lib/mysql:rw"
volumes:
  credit-facility-volume: {}

2.credit-facility-service在服务器上启动报错先肯定你是否已经切换到docker分支，而且本地构建能够成功，而后再打包部署

有兴趣的朋友，欢迎加我公众号一块儿交流，有问题能够留言，平时工做比较忙，我也抽时间尽可能回复每位朋友的留言，谢谢！

原文出处：https://www.cnblogs.com/evan-liang/p/12405745.html