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- 容器技术｜Docker 三剑客之 docker-compose
容器技术｜Docker 三剑客之 docker-compose
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? 答案是可以的, 不过显然需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, 用于在各种平台上快速创建具有 docker 服务的虚拟机的技术, 甚至可以通过指定 driver 来定制虚拟机的实现原理 (一般是 virtualbox).
docker-compose
docker 镜像在创建之后, 往往需要自己手动 pull 来获取镜像, 然后执行 run 命令来运行. 当服务需要用到多种容器, 容器之间又产生了各种依赖和连接的时候, 部署一个服务的手动操作是令人感到十分厌烦的.
dcoker-compose 技术, 就是通过一个. yml 配置文件, 将所有的容器的部署方法, 文件映射, 容器连接等等一系列的配置写在一个配置文件里, 最后只需要执行 docker-compose up 命令就会像执行脚本一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.
docker-swarm
swarm 是基于 docker 平台实现的集群技术, 他可以通过几条简单的指令快速的创建一个 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.
docker-compose 的工作流程
使用 Compose 仅需要三步:
1, 用一个定义你的应用程序的环境, Dockerfile 这样它就可以在任何地方再现.
2, 定义组成您的应用程序的服务, docker-compose.yml 以便它们可以在隔离的环境中一起运行.
3, 运行 docker-compose up 和撰写启动并运行您的整个应用程序.
参考文章: https://docs.docker.com/compose/overview/
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
docker-compose 管理命令介绍
Compose 具有管理应用程序整个生命周期的命令:
启动, 停止和重建服务
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
docker-compose 运行时是需要指定 service 名称, 可以同时指定多个, 也可以不指定. 不指定时默认就是对配置文件中所有的 service 执行命令.
- -f #用于指定配置文件
- -p #用于指定项目名称
- docker-compose build
用来创建或重新创建服务使用的镜像
docker-compose build service_a
创建一个镜像名叫 service_a
docker-compose kill
用于通过容器发送 SIGKILL 信号强行停止服务
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 不同作用, 此命令会显示停止后的容器 (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所有容器
docker-compose restart service_name
只有正在运行的服务可以使用重启命令, 停止的服务是不可以重启
docker-compose rm
删除停止的服务 (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.
但两者之间还是有两点不同之处
1,run 指定的命令会直接覆盖掉 service 配置中指定的命令
2,run 命令启动的容器不会创建在 service 配置中指定的端口, 如果需要指定使用 --service-ports 指定
docker-compose start/stop
docker-compose start 启动运行某个服务的所有容器
docker-compose stop 启动运行某个服务的所有容器
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)
docker-compose 配置文件实例
一个 docker-compose.yml 的实例文件如下
- 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
下面将配置文件做个简单的解释说明
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
整体的目录结构如下
- [root@docker docker]# tree ./
- ./
- docker-compose.yml
- nginx
- ?? nginx.conf
- webserver
- index.html
- 2 directories, 3 files
配置文件如下
[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;
- }
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
# 如果启动时不指定里面的服务名称, 就是直接启动配置文件里所有的服务
浏览器测试是否正常访问
然后我们修改相应的首页文件如下
- [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>
再次打开浏览器查看效果
# 是不是非常的方便
使用 Docker-Compose 部署 nginx 代理 Tomcat 集群, 实现负载均衡
大体步骤分为以下四步
1, 下载所需的文件 tomcat,jdk
2, 编写 dockerfile 来布署 tomcat 与 java 环境, 生成镜像文件
3, 编写 docker-compose.yml 配置文件, 启动所有容器服务
4, 测试负载均衡
具体配置文件如下
- # 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
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
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
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"]
启动所有容器服务
- [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
查看启动情况
- [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
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
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" "-"
来源: http://blog.51cto.com/mingongge/2129754