容器技术｜Docker三剑客之docker-compose

时间 2019-11-30

原文原文链接

三剑客简介

docker-machine

docker技术是基于Linux内核的cgroup技术实现的，那么问题来了，在非Linux平台上是否就不能使用docker技术了呢？答案是能够的，不过显然须要借助虚拟机去模拟出Linux环境来。 docker-machine就是docker公司官方提出的，用于在各类平台上快速建立具备docker服务的虚拟机的技术，甚至能够经过指定driver来定制虚拟机的实现原理（通常是virtualbox）。html

docker-compose

docker镜像在建立以后，每每须要本身手动pull来获取镜像，而后执行run命令来运行。当服务须要用到多种容器，容器之间又产生了各类依赖和链接的时候，部署一个服务的手动操做是使人感到十分厌烦的。 dcoker-compose技术，就是经过一个.yml配置文件，将全部的容器的部署方法、文件映射、容器链接等等一系列的配置写在一个配置文件里，最后只须要执行docker-compose up命令就会像执行脚本同样的去一个个安装容器并自动部署他们，极大的便利了复杂服务的部署。java

docker-swarm

swarm是基于docker平台实现的集群技术，他能够经过几条简单的指令快速的建立一个docker集群，接着在集群的共享网络上部署应用，最终实现分布式的服务。linux

docker-compose 的工做流程

使用Compose仅须要三步：nginx

一、用一个定义你的应用程序的环境，Dockerfile这样它就能够在任何地方再现。二、定义组成您的应用程序的服务，docker-compose.yml 以便它们能够在隔离的环境中一块儿运行。三、运行docker-compose up和撰写启动并运行您的整个应用程序。git

参考文章：https://docs.docker.com/compose/overview/github

docker-compose安装布署

[root@docker ~]# curl -L https://github.com/docker/compose/releases/download/1.21.2/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   617    0   617    0     0    396      0 --:--:--  0:00:01 --:--:--   397
100 10.3M  100 10.3M    0     0   678k      0  0:00:15  0:00:15 --:--:-- 1876k
[root@docker ~]# chmod +x /usr/local/bin/docker-compose 
[root@docker ~]# docker-compose --version
docker-compose version 1.21.2, build a133471
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docker-compose管理命令介绍

Compose具备管理应用程序整个生命周期的命令：

启动，中止和重建服务

查看正在运行的服务的状态
流式传输运行服务的日志输出
在服务上运行一次性命令

[root@docker ~]# 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 deploy
                              keys in v3 files to their non-Swarm equivalent

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
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**docker-compose 运行时是须要指定service名称，**能够同时指定多个，也能够不指定。不指定时默认就是对配置文件中全部的service执行命令。web

-f #用于指定配置文件 -p #用于指定项目名称docker

**docker-compose build ** 用来建立或从新建立服务使用的镜像 docker-compose build service_a 建立一个镜像名叫service_aapache

docker-compose kill 用于经过容器发送SIGKILL信号强行中止服务centos

docker-compose logs 显示service的日志信息

docker-compose pause/unpause docker-compose pause #暂停服务 docker-compose unpause #恢复被暂停的服务

docker-compose port 用于查看服务中的端口与物理机的映射关系 docker-compose port nginx_web 80 查看服务中80端口映射到物理机上的那个端口

dokcer-compose ps 用于显示当前项目下的容器注意，此命令与docker ps不一样做用，此命令会显示中止后的容器（状态为Exited），只征对某个项目。

docker-compose pull 用于拉取服务依赖的镜像

docker-compose restart 用于重启某个服务中的全部容器 docker-compose restart service_name 只有正在运行的服务可使用重启命令，中止的服务是不能够重启

docker-compose rm 删除中止的服务（服务里的容器）

-f #强制删除 -v #删除与容器相关的卷（volumes）

docker-compose run 用于在服务中运行一个一次性的命令。这个命令会新建一个容器，它的配置和srvice的配置相同。但二者之间仍是有两点不一样之处

一、run指定的命令会直接覆盖掉service配置中指定的命令二、run命令启动的容器不会建立在service配置中指定的端口，若是须要指定使用--service-ports指定

docker-compose start/stop docker-compose start 启动运行某个服务的全部容器 docker-compose stop 中止运行某个服务的全部容器

docker-compose scale 指定某个服务启动的容器个数

[root@docker ~]# docker-compose scale --help
Numbers are specified in the form `service=num` as arguments.
For example:

    $ docker-compose scale web=2 worker=3

This command is deprecated. Use the up command with the `--scale` flag
instead.

Usage: scale [options] [SERVICE=NUM...]

Options:
  -t, --timeout TIMEOUT      Specify a shutdown timeout in seconds.
                             (default: 10)
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docker-compose配置文件实例

一个docker-compose.yml的实例文件以下

version: "3"
services:
  nginx:
    container_name: web-nginx
    image: nginx:latest
	restart: always
	ports:
	  - 80:80
	volumes:
	- ./webserver:/webserver
	- ./nginx/nginx.conf:/etc/nginx/nginx.conf
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下面将配置文件作个简单的解释说明

docker-compose的配置文件是一个.yml格式的文件
第一部分
version: "3"  #指定语法的版本
第二部分
services:     #定义服务
  nginx:      #服务的名称，-p参数后接服务名称
    container_name: web-nginx    #容器的名称
    image: nginx:latest          #镜像
	restart: always
	ports:                       #端口映射
	  - 80:80
第三部分
volumes:       #物理机与容器的磁盘映射关系
	- ./webserver:/webserver
	- ./nginx/nginx.conf:/etc/nginx/nginx.conf
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总体的目录结构以下

[root@docker docker]# tree ./
./
├── docker-compose.yml
├── nginx
│?? └── nginx.conf
└── webserver
    └── index.html

2 directories, 3 files
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配置文件以下

[root@docker docker]# cat webserver/index.html 
welcome to nginx server!!!!!!!!!
[root@docker docker]# cat nginx/nginx.conf
#user  nginx;
worker_processes  1;
error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;
    client_max_body_size 10m;  
    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

server {
    listen       80;
    server_name  localhost;

    location / {
        root   /webserver;
        index  index.html index.htm;
    }

}
    include /etc/nginx/conf.d/*.conf;
}
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使用命令启动容器

[root@docker docker]# docker-compose up -d
Pulling nginx (nginx:1.14)...
Trying to pull repository docker.io/library/nginx ... 
1.14: Pulling from docker.io/library/nginx
f2aa67a397c4: Already exists
6160d1ac49e9: Pull complete
046b67408776: Pull complete
Digest: sha256:85ab7c44474df01422fe8fdbf9c28e497df427e8a67ce6d47ba027c49be4bdc6
Status: Downloaded newer image for docker.io/nginx:1.14
Creating nginx-server ... done
[root@docker docker]# lsof -i :80
COMMAND   PID USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME
docker-pr 891 root    4u  IPv6 1187080      0t0  TCP *:http (LISTEN)
[root@docker docker]# docker ps |grep nginx
07ca899cc44b   nginx:1.14   "nginx -g 'daemon ..."   29 seconds ago  Up 28 seconds  0.0.0.0:80->80/tcp  nginx-server
#若是启动时不指定里面的服务名称，就是直接启动配置文件里全部的服务
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浏览器测试是否正常访问

而后咱们修改相应的首页文件以下

[root@docker docker]# cat webserver/index.html 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>welcome to nginx web stie</title>
</head>
<body>
   <h2>欢迎来nginx站点</h2>
</body>
</html>
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再次打开浏览器查看效果

#是否是很是的方便

使用Docker-Compose部署nginx代理Tomcat集群,实现负载均衡

大致步骤分为如下四步

一、下载所需的文件tomcat,jdk 二、编写dockerfile来布署tomcat与java环境，生成镜像文件三、编写docker-compose.yml配置文件，启动全部容器服务四、测试负载均衡

具体配置文件以下

#整个目录结构
[root@master java]# tree ./
./
├── docker-compose.yml
├── etc
│   └── localtime
├── nginx
│   └── nginx.conf
├── tomcat
│   ├── apache-tomcat-8.5.31.tar.gz
│   ├── Dockerfile
│   └── jdk-8u144-linux-x64.tar.gz
└── webserver
    ├── tomcatA
    │   └── index.jsp
    └── tomcatB
        └── index.jsp

6 directories, 8 files
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两个测试首页文件

[root@master java]# cat webserver/tomcatA/index.jsp 
welcome to tomcat-A server
[root@master java]# cat webserver/tomcatB/index.jsp 
welcome to tomcat-B server
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配置文件

[root@master java]# cat docker-compose.yml 
version: "3"
services:
  nginx:
    image: nginx:1.14
    restart: always
    ports:
      - 80:80
    links:
      - tomcat1:tomcat1
      - tomcat2:tomcat2
    volumes:
      - ./webserver:/webserver
      - ./nginx/nginx.conf:/etc/nginx/nginx.conf
      - ./etc/localtime:/etc/localtime
    depends_on:
      - tomcat1
      - tomcat2

  tomcat1:
    hostname: tomcat1
    build: ./tomcat
    volumes:
      - ./webserver/tomcatA:/usr/local/apache-tomcat-8.5.31/webapps/ROOT
      - ./etc/localtime:/etc/localtime

  tomcat2:
    hostname: tomcat2
    build: ./tomcat
    volumes:
      - ./webserver/tomcatB:/usr/local/apache-tomcat-8.5.31/webapps/ROOT
      - ./etc/localtime:/etc/localtime
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安装JAVA环境

[root@master java]# cat tomcat/Dockerfile 
FROM centos

ADD jdk-8u144-linux-x64.tar.gz /usr/local
ENV JAVA_HOME /usr/local/jdk1.8.0_144
ADD apache-tomcat-8.5.31.tar.gz /usr/local

EXPOSE 8080
ENTRYPOINT ["/usr/local/apache-tomcat-8.5.31/bin/catalina.sh", "run"]
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启动全部容器服务

[root@master java]# docker-compose up
Building tomcat1
Step 1/6 : FROM centos
Trying to pull repository docker.io/library/centos ... 
latest: Pulling from docker.io/library/centos
7dc0dca2b151: Pull complete
Digest: sha256:b67d21dfe609ddacf404589e04631d90a342921e81c40aeaf3391f6717fa5322
Status: Downloaded newer image for docker.io/centos:latest
 ---> 49f7960eb7e4
Step 2/6 : ADD jdk-8u144-linux-x64.tar.gz /usr/local
 ---> 8c9e14062a24
Removing intermediate container a499940235ac
Step 3/6 : ENV JAVA_HOME /usr/local/jdk1.8.0_144
 ---> Running in cefedfd97f61
 ---> 12528cd5a517
Removing intermediate container cefedfd97f61
Step 4/6 : ADD apache-tomcat-8.5.31.tar.gz /usr/local
 ---> 246fa08bea1c
Removing intermediate container a1aaaa2bf0b8
Step 5/6 : EXPOSE 8080
 ---> Running in 87c4b41f3c1e
 ---> fd207f27b830
Removing intermediate container 87c4b41f3c1e
Step 6/6 : ENTRYPOINT /usr/local/apache-tomcat-8.5.31/bin/catalina.sh run
 ---> Running in 9adaed8e3ab9
 ---> b6fc6d3925f7
Removing intermediate container 9adaed8e3ab9
Successfully built b6fc6d3925f7
WARNING: Image for service tomcat1 was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Building tomcat2
Step 1/6 : FROM centos
 ---> 49f7960eb7e4
Step 2/6 : ADD jdk-8u144-linux-x64.tar.gz /usr/local
 ---> Using cache
 ---> 8c9e14062a24
Step 3/6 : ENV JAVA_HOME /usr/local/jdk1.8.0_144
 ---> Using cache
 ---> 12528cd5a517
Step 4/6 : ADD apache-tomcat-8.5.31.tar.gz /usr/local
 ---> Using cache
 ---> 246fa08bea1c
Step 5/6 : EXPOSE 8080
 ---> Using cache
 ---> fd207f27b830
Step 6/6 : ENTRYPOINT /usr/local/apache-tomcat-8.5.31/bin/catalina.sh run
 ---> Using cache
 ---> b6fc6d3925f7
Successfully built b6fc6d3925f7
WARNING: Image for service tomcat2 was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Pulling nginx (nginx:1.14)...
Trying to pull repository docker.io/library/nginx ... 
1.14: Pulling from docker.io/library/nginx
f2aa67a397c4: Already exists
6160d1ac49e9: Pull complete
046b67408776: Pull complete
Digest: sha256:85ab7c44474df01422fe8fdbf9c28e497df427e8a67ce6d47ba027c49be4bdc6
Status: Downloaded newer image for docker.io/nginx:1.14
Creating java_tomcat2_1 ... done
Creating java_tomcat1_1 ... done
Creating java_nginx_1   ... done
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查看启动状况

[root@master java]# docker-compose ps
     Name                   Command               State         Ports       
----------------------------------------------------------------------------
java_nginx_1     nginx -g daemon off;             Up      0.0.0.0:80->80/tcp
java_tomcat1_1   /usr/local/apache-tomcat-8 ...   Up      8080/tcp          
java_tomcat2_1   /usr/local/apache-tomcat-8 ...   Up      8080/tcp  
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检测负载均衡

[root@master java]# curl http://localhost
welcome to tomcat-A server
[root@master java]# curl http://localhost
welcome to tomcat-B server
[root@master java]# curl http://localhost
welcome to tomcat-A server
[root@master java]# curl http://localhost
welcome to tomcat-B server
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浏览器访问测试负载均衡

查看日志输出信息

nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:33 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:34 +0000] "GET / HTTP/1.1" 499 0 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:34 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:36 +0000] "GET / HTTP/1.1" 499 0 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:36 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:36 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:37 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:37 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:37 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:37 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:38 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:38 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:38 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:38 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:38 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:14:39 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
nginx_1    | 172.19.0.1 - - [08/Jun/2018:02:18:30 +0000] "GET / HTTP/1.1" 200 27 "-" "curl/7.29.0" "-"
nginx_1    | 172.19.0.1 - - [08/Jun/2018:02:18:31 +0000] "GET / HTTP/1.1" 200 27 "-" "curl/7.29.0" "-"
nginx_1    | 172.19.0.1 - - [08/Jun/2018:02:18:32 +0000] "GET / HTTP/1.1" 200 27 "-" "curl/7.29.0" "-"
nginx_1    | 172.19.0.1 - - [08/Jun/2018:02:18:33 +0000] "GET / HTTP/1.1" 200 27 "-" "curl/7.29.0" "-"
nginx_1    | 192.168.22.170 - - [08/Jun/2018:02:19:32 +0000] "GET / HTTP/1.1" 200 27 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36" "-"
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