(Three) docker-compose tutorial

table of Contents

 

Introduction

1. Get started quickly

2. Run multiple services

Command expansion

3. Content supplement

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Introduction

Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a Compose file to configure your application's services. Then, using a single command, you create and start all the services from your configuration.

Compose is a tool for defining and running multi-container Docker applications. Using combination, you can use the combination file to configure the application's services. Then, use a single command to create and start all services from the configuration.

We logocan see from the above that, to put it bluntly, this thing is a tool (zhang) for managing containers (yu), we can conveniently use it to manage our dockercontainers, which can greatly simplify the complex operations of the command line.

1. Get started quickly

If you are Macor the Windowsuser uses the desktop version of the Dockerapplication, it will be installed for you by default docker-compose(replaced with dc below), if it is centos, you can use the command to yum -y install docker-composebe too simple and not to explain too much.

Check the version, it can be displayed to prove that the installation is successful

lianying@lianyingdeiMac ~ % docker-compose version
docker-compose version 1.27.2, build 18f557f9
docker-py version: 4.3.1
CPython version: 3.7.7
OpenSSL version: OpenSSL 1.1.1g  21 Apr 2020

Next, we have a need, run a service-amount to /usr/local, map port as 8082and add servicehostdomain name mapping intranet ip, many people can think that it should be a lengthy dockercommand

docker run -idt -p 8082:8082 -v /Users/objcat/jar/service-a.jar:/usr/local/service-a.jar --name service-a java sh -c "echo 192.168.1.126 servicehost >> /etc/hosts && java -jar /usr/local/service-a.jar"

So a big lump, it seems very inconvenient, then we are used docker-composeto optimize the look

First create a docker-compose.ymlfile named

lianying@lianyingdeiMac SpringBoot01 % touch docker-compose.yml
lianying@lianyingdeiMac SpringBoot01 % ls
docker-compose.yml

Then just open it with a text editor and write the following

version: '2'
services:
 service-a: 
   image: java
   volumes:
     - /Users/objcat/jar/service-a.jar:/usr/local/service-a.jar
   ports:
     - 8082:8082
   command:
     - /bin/sh
     - -c
     - |
       echo 192.168.1.126 servicehost >> /etc/hosts
       java -jar /usr/local/service-a.jar

Does this seem to be much clearer, let's run it next

lianying@lianyingdeiMac SpringBoot01 % docker-compose up -d
Starting springboot01_service-a_1 ... done

-dRun in the background, otherwise the run log will appear on your screen. . .

Then check the running status

zhangyideMacBook-Pro:jar objcat$ docker-compose ps
         Name                   Command           State           Ports         
--------------------------------------------------------------------------------
jar_service-             /bin/sh -c echo          Up      0.0.0.0:8082->8082/tcp
a_1_5827fa3204e8         192.168.1. ...   

We can see that the service is up and running, let's try to visit
http://localhost:8082/hello

Success, this part comes to an end.

2. Run multiple services

Some people may ask, how do multiple services work? It's very simple, let's do it here.

Now I have to do is open the three services service-a, service-b, service-eureka, respectively, two and a registry service.

Let's improve itdocker-compose.yml

version: '2'

services:

 service-eureka: 
   image: java
   volumes:
     - /Users/objcat/jar/service-eureka.jar:/usr/local/service-eureka.jar
   ports:
     - 8081:8081
   command:
     - /bin/sh
     - -c
     - |
       echo 192.168.1.126 servicehost >> /etc/hosts
       java -jar /usr/local/service-eureka.jar

 service-a: 
   image: java
   volumes:
     - /Users/objcat/jar/service-a.jar:/usr/local/service-a.jar
   ports:
     - 8082:8082
   command:
     - /bin/sh
     - -c
     - |
       echo 192.168.1.126 servicehost >> /etc/hosts
       java -jar /usr/local/service-a.jar

 service-b: 
   image: java
   volumes:
     - /Users/objcat/jar/service-b.jar:/usr/local/service-b.jar
   ports:
     - 8083:8083
   command:
     - /bin/sh
     - -c
     - |
       echo 192.168.1.126 servicehost >> /etc/hosts
       java -jar /usr/local/service-b.jar

Let's run it

zhangyideMacBook-Pro:jar objcat$ docker-compose up -d
jar_service-a_1_5827fa3204e8 is up-to-date
Creating jar_service-b_1_f7d01c317fab      ... done
Creating jar_service-eureka_1_57bb1a079e9b ... done
zhangyideMacBook-Pro:jar objcat$ docker-compose ps
              Name                             Command               State           Ports         
---------------------------------------------------------------------------------------------------
jar_service-a_1_5827fa3204e8        /bin/sh -c echo 192.168.1. ...   Up      0.0.0.0:8082->8082/tcp
jar_service-b_1_be87c0458e53        /bin/sh -c echo 192.168.1. ...   Up      0.0.0.0:8083->8083/tcp
jar_service-eureka_1_933d5a60af31   /bin/sh -c echo 192.168.1. ...   Up      0.0.0.0:8081->8081/tcp
zhangyideMacBook-Pro:jar objcat$ 

Registry

Visit service-a

Visit service-b

At this point we can already run multiple services! ! ! ! End of class--

Command expansion

Out of service

zhangyideMacBook-Pro:jar objcat$ docker-compose stop
Stopping jar_service-eureka_1_933d5a60af31 ... done
Stopping jar_service-b_1_be87c0458e53      ... done
Stopping jar_service-a_1_5827fa3204e8      ... done

Stop a single service

zhangyideMacBook-Pro:jar objcat$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
94c3472638c8        java                "/bin/sh -c 'echo 19…"   16 minutes ago      Up 6 seconds        0.0.0.0:8081->8081/tcp   jar_service-eureka_1_933d5a60af31
8d1dfa0ec642        java                "/bin/sh -c 'echo 19…"   16 minutes ago      Up 6 seconds        0.0.0.0:8083->8083/tcp   jar_service-b_1_be87c0458e53
6be5f9d8f423        java                "/bin/sh -c 'echo 19…"   33 minutes ago      Up 6 seconds        0.0.0.0:8082->8082/tcp   jar_service-a_1_5827fa3204e8
zhangyideMacBook-Pro:jar objcat$ docker stop 6be5f9d8f423
6be5f9d8f423

Re-run the service

zhangyideMacBook-Pro:jar objcat$ docker-compose up -d
jar_service-b_1_be87c0458e53 is up-to-date
Starting jar_service-a_1_5827fa3204e8 ... 
Starting jar_service-a_1_5827fa3204e8 ... done
zhangyideMacBook-Pro:jar objcat$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
94c3472638c8        java                "/bin/sh -c 'echo 19…"   19 minutes ago      Up 3 minutes        0.0.0.0:8081->8081/tcp   jar_service-eureka_1_933d5a60af31
8d1dfa0ec642        java                "/bin/sh -c 'echo 19…"   19 minutes ago      Up 3 minutes        0.0.0.0:8083->8083/tcp   jar_service-b_1_be87c0458e53
6be5f9d8f423        java                "/bin/sh -c 'echo 19…"   36 minutes ago      Up 13 seconds       0.0.0.0:8082->8082/tcp   jar_service-a_1_5827fa3204e8

We can see that it docker-composewill automatically recognize the open state of the container and open the one that needs to be opened for us

3. Content supplement

1. Maybe many people do echo 192.168.1.126 servicehost >> /etc/hostsn't understand me very well

Let me talk about it here. The meaning of this command is to add the servicehostdomain name to the hostsfile. The purpose is to let me eurekadiscover my service, not to write the address in the configuration file. The service corresponding to this command is configured as

server:
  #服务端口号
  port: 8082
spring:
  application:
    #服务名称 - 服务之间使用名称进行通讯
    name: service-objcat-a
eureka:
  client:
    service-url:
      #填写注册中心服务器地址
      defaultZone: http://servicehost:8081/eureka
    #是否需要将自己注册到注册中心
    register-with-eureka: true
    #是否需要搜索服务信息
    fetch-registry: true
  instance:
    prefer-ip-address: true
    instance-id: ${spring.cloud.client.ip-address}:${server.port}
management:
  endpoints:
    web:
      exposure:
        include: "*"