目录 Docker Compose 6.1 业务背景 6.2 Docker传统方式实现 6.2.1 写Python代码&build image 6.2.2 获取Redis的image 6.2.3 创建两个container 6.2.4 访问测试 6.3 简介和安装 6.3.1 简介 6.3.2 安装 6.4 docker compose实现 6.4.1 同样的前期准备 6.4.2 编写docker-compose.yaml文件 6.5 详解docker-compose.yml文件 6.6 docker-compose常见操作 6.7 scale扩缩容 07 Docker Swarm 7.1 Install Swarm 7.1.1 环境准备 7.1.2 搭建Swarm集群 7.1.3 在线的 7.2 Swarm基本操作 7.2.1 Service 7.2.2 多机通信overlay网络[3.7的延续] 7.2.2.1 传统手动方式实现 7.2.2.1.1 一台centos上,分别创建容器 7.2.2.1.2 使用docker compose创建 7.2.2.2 Swarm中实现 7.3 Routing Mesh 7.3.1 Ingress 7.4.2 Internal 7.5 Stack
Docker Compose
官网:https://docs.docker.com/compose/
6.1 业务背景 6.2 Docker传统方式实现 6.2.1 写Python代码&build image
(1)创建文件夹
1 2 mkdir -p /tmp/composetest cd /tmp/composetest
(2)创建app.py文件,写业务内容
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 import timeimport redisfrom flask import Flaskapp = 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)
(3)新建requirements.txt文件
(4)编写Dockerfile
1 2 3 4 5 6 7 8 9 FROM python:3.7 -alpineWORKDIR /code ENV FLASK_APP app.pyENV 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 COPY . . CMD ["flask" , "run" ]
(5)根据Dockerfile生成image
1 docker build -t python-app-image .
(6)查看images:docker images
1 python-app-image latest 7e1d81f366b7 3 minutes ago 213MB
6.2.2 获取Redis的image 1 docker pull redis:alpine
6.2.3 创建两个container
(1)创建网络
1 2 docker network ls docker network create --subnet=172.20.0.0/24 app-net
(1)创建python程序的container,并指定网段和端口
1 docker run -d --name web -p 5000:5000 --network app-net python-app-image
(2)创建redis的container,并指定网段
1 docker run -d --name redis --network app-net redis:alpine
6.2.4 访问测试 ip[centos]:5000
6.3 简介和安装 6.3.1 简介
官网:https://docs.docker.com/compose/
1 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.
6.3.2 安装
Linux环境中需要单独安装
官网:https://docs.docker.com/compose/install/
1 sudo curl -L "https://github.com/docker/compose/releases/download/1.24.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
1 sudo chmod +x /usr/local/bin/docker-compose
6.4 docker compose实现
reference:https://docs.docker.com/compose/gettingstarted/
6.4.1 同样的前期准备 新建目录,比如composetest
进入目录,编写app.py代码
创建requirements.txt文件
编写Dockerfile
6.4.2 编写docker-compose.yaml文件 默认名称,当然也可以指定,docker-compose.yaml
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 version: '3' services: web: build: . ports: - "5000:5000" networks: - app-net redis: image: "redis:alpine" networks: - app-net networks: app-net: driver: bridge
(1)通过docker compose创建容器
(2)访问测试
6.5 详解docker-compose.yml文件
(1)version: ‘3’
(2)services
(3)networks
1 相当于docker network create app-net
(4)volumes
(5)image
1 表示使用哪个镜像,本地build则用build,远端则用image
(6)ports
(7)environment
6.6 docker-compose常见操作 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 (1)查看版本 docker-compose version (2)根据yml创建service docker-compose up 指定yaml:docker-compose up -f xxx.yaml 后台运行:docker-compose up (3)查看启动成功的service docker-compose ps 也可以使用docker ps (4)查看images docker-compose images (5)停止/启动service docker-compose stop/start (6)删除service[同时会删除掉network和volume] docker-compose down (7)进入到某个service docker-compose exec redis sh
6.7 scale扩缩容
(1)修改docker-compose.yaml文件,主要是把web的ports去掉,不然会报错
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 version: '3' services: web: build: . networks: - app-net redis: image: "redis:alpine" networks: - app-net networks: app-net: driver: bridge
(2)创建service
(3)若要对python容器进行扩缩容
1 2 3 docker-compose up --scale web=5 -d docker-compose ps docker-compose logs web
07 Docker Swarm
官网:https://docs.docker.com/swarm/
7.1 Install Swarm 7.1.1 环境准备
(1)根据Vagrantfile创建3台centos机器
[大家可以根据自己实际的情况准备3台centos机器,不一定要使用vagrant+virtualbox ]
新建swarm-docker-centos7文件夹,创建Vagrantfile
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 boxes = [ { :name => "manager-node" , :eth1 => "192.168.0.11" , :mem => "1024" , :cpu => "1" }, { :name => "worker01-node" , :eth1 => "192.168.0.12" , :mem => "1024" , :cpu => "1" }, { :name => "worker02-node" , :eth1 => "192.168.0.13" , :mem => "1024" , :cpu => "1" } ] Vagrant .configure(2 ) do |config | config.vm.box = "centos/7" boxes.each do |opts | config.vm.define opts[:name ] do |config | config.vm.hostname = opts[:name ] config.vm.provider "vmware_fusion" do |v | v.vmx["memsize" ] = opts[:mem ] v.vmx["numvcpus" ] = opts[:cpu ] end config.vm.provider "virtualbox" do |v | v.customize ["modifyvm" , :id , "--memory" , opts[:mem ]] v.customize ["modifyvm" , :id , "--cpus" , opts[:cpu ]] v.customize ["modifyvm" , :id , "--name" , opts[:name ]] end config.vm.network :public_network , ip: opts[:eth1 ] end end end
(2)进入到对应的centos里面,使得root账户能够登陆,从而使用XShell登陆
1 2 3 4 5 6 vagrant ssh manager-node/worker01-node/worker02-node sudo -i vi /etc/ssh/sshd_config 修改PasswordAuthentication yes passwd 修改密码 systemctl restart sshd
(3)在win上ping一下各个主机,看是否能ping通
(4)在每台机器上安装docker engine
小技巧:要想让每个shell窗口一起执行同样的命令”查看–>撰写–>撰写窗口–>全部会话”
7.1.2 搭建Swarm集群
(1)进入manager
提示:manager node也可以作为worker node提供服务
1 docker swarm init --advertise-addr=192.168.0.11
注意观察日志,拿到worker node加入manager node的信息
1 docker swarm join --token SWMTKN-1-0a5ph4nehwdm9wzcmlbj2ckqqso38pkd238rprzwcoawabxtdq-arcpra6yzltedpafk3qyvv0y3 192.168.0.11:2377
(2)进入两个worker
1 docker swarm join --token SWMTKN-1-0a5ph4nehwdm9wzcmlbj2ckqqso38pkd238rprzwcoawabxtdq-arcpra6yzltedpafk3qyvv0y3 192.168.0.11:2377
日志打印
1 This node joined a swarm as a worker.
(3)进入到manager node查看集群状态
(4)node类型的转换
可以将worker提升成manager,从而保证manager的高可用
1 2 3 4 5 docker node promote worker01-node docker node promote worker02-node #降级可以用demote docker node demote worker01-node
7.1.3 在线的
http://labs.play-with-docker.com
7.2 Swarm基本操作 7.2.1 Service
(1)创建一个tomcat的service
1 docker service create --name my-tomcat tomcat
(2)查看当前swarm的service
(3)查看service的启动日志
1 docker service logs my-tomcat
(4)查看service的详情
1 docker service inspect my-tomcat
(5)查看my-tomcat运行在哪个node上
1 docker service ps my-tomcat
日志
1 2 ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS u6o4mz4tj396 my-tomcat.1 tomcat:latest worker01-node Running Running 3 minutes ago
(6)水平扩展service
1 2 3 docker service scale my-tomcat=3 docker service ls docker service ps my-tomcat
日志:可以发现,其他node上都运行了一个my-tomcat的service
1 2 3 4 5 [root@manager-node ~]# docker service ps my-tomcat ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS u6o4mz4tj396 my-tomcat.1 tomcat:latest worker01-node Running Running 8 minutes ago v505wdu3fxqo my-tomcat.2 tomcat:latest manager-node Running Running 46 seconds ago wpbsilp62sc0 my-tomcat.3 tomcat:latest worker02-node Running Running 49 seconds ago
此时到worker01-node上:docker ps,可以发现container的name和service名称不一样,这点要知道
1 2 CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES bc4b9bb097b8 tomcat:latest "catalina.sh run" 10 minutes ago Up 10 minutes 8080/tcp my-tomcat.1.u6o4mz4tj3969a1p3mquagxok
(7)如果某个node上的my-tomcat挂掉了,这时候会自动扩展
1 2 3 4 5 6 [worker01-node] docker rm -f containerid [manager-node] docker service ls docker service ps my-tomcat
(8)删除service
1 docker service rm my-tomcat
7.2.2 多机通信overlay网络[3.7的延续]
业务场景:workpress+mysql实现个人博客搭建
https://hub.docker.com/_/wordpress?tab=description
7.2.2.1 传统手动方式实现 7.2.2.1.1 一台centos上,分别创建容器 1 2 3 4 5 6 7 8 9 10 11 01-创建mysql容器[创建完成等待一会,注意mysql的版本] docker run -d --name mysql -v v1:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=examplepass -e MYSQL_DATABASE=db_wordpress mysql:5.6 02-创建wordpress容器[将wordpress的80端口映射到centos的8080端口] docker run -d --name wordpress --link mysql -e WORDPRESS_DB_HOST=mysql:3306 -e WORDPRESS_DB_USER=root -e WORDPRESS_DB_PASSWORD=examplepass -e WORDPRESS_DB_NAME=db_wordpress -p 8080:80 wordpress 03-查看默认bridge的网络,可以发现两个容器都在其中 docker network inspect bridge 04-访问测试 win浏览器中输入:ip[centos]:8080,一直下一步
7.2.2.1.2 使用docker compose创建
docker-compose的方式还是在一台机器中,网络这块很清晰
1 2 3 4 5 01-创建wordpress-mysql文件夹 mkdir -p /tmp/wordpress-mysql cd /tmp/wordpress-mysql 02-创建docker-compose.yml文件
文件内容
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 version: '3.1' services: wordpress: image: wordpress restart: always ports: - 8080 :80 environment: WORDPRESS_DB_HOST: db WORDPRESS_DB_USER: exampleuser WORDPRESS_DB_PASSWORD: examplepass WORDPRESS_DB_NAME: exampledb volumes: - wordpress:/var/www/html db: image: mysql:5.7 restart: always environment: MYSQL_DATABASE: exampledb MYSQL_USER: exampleuser MYSQL_PASSWORD: examplepass MYSQL_RANDOM_ROOT_PASSWORD: '1' volumes: - db:/var/lib/mysql volumes: wordpress: db:
1 2 3 4 5 6 7 8 9 03-根据docker-compose.yml文件创建service docker-compose up -d 04-访问测试 win10浏览器ip[centos]:8080,一直下一步 05-值得关注的点是网络 docker network ls docker network inspect wordpress-mysql_default
7.2.2.2 Swarm中实现
还是wordpress+mysql的案例,在docker swarm集群中怎么玩呢?
(1)创建一个overlay网络,用于docker swarm中多机通信
1 2 3 4 【manager-node】 docker network create -d overlay my-overlay-net docker network ls[此时worker node查看不到]
(2)创建mysql的service
1 2 3 4 5 6 7 【manager-node】 01-创建service docker service create --name mysql --mount type=volume,source=v1,destination=/var/lib/mysql --env MYSQL_ROOT_PASSWORD=examplepass --env MYSQL_DATABASE=db_wordpress --network my-overlay-net mysql:5.6 02-查看service docker service ls docker service ps mysql
(3)创建wordpress的service
1 2 3 4 5 6 7 8 01-创建service [注意之所以下面可以通过mysql名字访问,也是因为有DNS解析] docker service create --name wordpress --env WORDPRESS_DB_USER=root --env WORDPRESS_DB_PASSWORD=examplepass --env WORDPRESS_DB_HOST=mysql:3306 --env WORDPRESS_DB_NAME=db_wordpress -p 8080:80 --network my-overlay-net wordpress 02-查看service docker service ls docker service ps mysql 03-此时mysql和wordpress的service运行在哪个node上,这时候就能看到my-overlay-net的网络
(4)测试
1 win浏览器访问ip[manager/worker01/worker02]:8080都能访问成功
(5)查看my-overlay-net
1 docker network inspect my-overlay-net
(6)为什么没有用etcd?docker swarm中有自己的分布式存储机制
7.3 Routing Mesh 7.3.1 Ingress
通过前面的案例我们发现,部署一个wordpress的service,映射到主机的8080端口,这时候通过swarm集群中的任意主机ip: 8080都能成功访问,这是因为什么?
把问题简化:docker service create –name tomcat -p 8080:8080 –network my-overlay-net tomcat
(1)记得使用一个自定义的overlay类型的网络
1 --network my-overlay-net
(2)查看service情况
1 2 docker service ls docker service ps tomcat
(3)访问3台机器的ip:8080测试
7.4.2 Internal
之前在实战wordpress+mysql的时候,发现wordpress中可以直接通过mysql名称访问
这样可以说明两点,第一是其中一定有dns解析,第二是两个service的ip是能够ping通的
思考:不妨再创建一个service,也同样使用上述tomcat的overlay网络,然后来实验
docker service create –name whoami -p 8000:8000 –network my-overlay-net -d jwilder/whoami
(1)查看whoami的情况
1 docker service ps whoami
(2)在各自容器中互相ping一下彼此,也就是容器间的通信
1 2 3 4 5 6 7 8 9 10 #tomcat容器中ping whoami docker exec -it 9d7d4c2b1b80 ping whoami 64 bytes from bogon (10.0.0.8): icmp_seq=1 ttl=64 time=0.050 ms 64 bytes from bogon (10.0.0.8): icmp_seq=2 ttl=64 time=0.080 ms #whoami容器中ping tomcat docker exec -it 5c4fe39e7f60 ping tomcat 64 bytes from bogon (10.0.0.18): icmp_seq=1 ttl=64 time=0.050 ms 64 bytes from bogon (10.0.0.18): icmp_seq=2 ttl=64 time=0.080 ms
(3)将whoami进行扩容
1 2 docker service scale whoami=3 docker service ps whoami #manager,worker01,worker02
(4)此时再ping whoami service,并且访问whoami服务
1 2 3 4 5 6 7 8 9 10 #ping docker exec -it 9d7d4c2b1b80 ping whoami 64 bytes from bogon (10.0.0.8): icmp_seq=1 ttl=64 time=0.055 ms 64 bytes from bogon (10.0.0.8): icmp_seq=2 ttl=64 time=0.084 ms #访问 docker exec -it 9d7d4c2b1b80 curl whoami:8000 [多访问几次] I'm 09f4158c81ae I'm aebc574dc990 I'm 7755bc7da921
小结:通过上述的实验可以发现什么?whoami服务对其他服务暴露的ip是不变的,但是通过whoami名称访问8000端口,确实访问到的是不同的service,就说明访问其实是像下面这张图。
也就是说whoami service对其他服务提供了一个统一的VIP入口,别的服务访问时会做负载均衡。
7.5 Stack
docker stack deploy:https://docs.docker.com/engine/reference/commandline/stack_deploy/
compose-file:https://docs.docker.com/compose/compose-file/
有没有发现上述部署service很麻烦?要是能够类似于docker-compose.yml文件那种方式一起管理该多少?这就要涉及到docker swarm中的Stack,我们直接通过前面的wordpress+mysql案例看看怎么使用咯。
(1)新建service.yml文件
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 version: '3' services: wordpress: image: wordpress ports: - 8080 :80 environment: WORDPRESS_DB_HOST: db WORDPRESS_DB_USER: exampleuser WORDPRESS_DB_PASSWORD: examplepass WORDPRESS_DB_NAME: exampledb networks: - ol-net volumes: - wordpress:/var/www/html deploy: mode: replicated replicas: 3 restart_policy: condition: on-failure delay: 5s max_attempts: 3 update_config: parallelism: 1 delay: 10s db: image: mysql:5.7 environment: MYSQL_DATABASE: exampledb MYSQL_USER: exampleuser MYSQL_PASSWORD: examplepass MYSQL_RANDOM_ROOT_PASSWORD: '1' volumes: - db:/var/lib/mysql networks: - ol-net deploy: mode: global placement: constraints: - node.role == manager volumes: wordpress: db: networks: ol-net: driver: overlay
(2)根据service.yml创建service
1 docker statck deploy -c service.yml my-service
(3)常见操作
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 01-查看stack具体信息 docker stack ls NAME SERVICES ORCHESTRATOR my-service 2 Swarm 02-查看具体的service docker stack services my-service ID NAME MODE REPLICAS IMAGE PORTS icraimlesu61 my-service_db global 1/1 mysql:5.7 iud2g140za5c my-service_wordpress replicated 3/3 wordpress:latest *:8080->80/tcp 03-查看某个service docker service inspect my-service-db "Endpoint": { "Spec": { "Mode": "vip" }, "VirtualIPs": [ { "NetworkID": "kz1reu3yxxpwp1lvnrraw0uq6", "Addr": "10.0.1.5/24" } ] }
(4)访问测试
win浏览器ip[manager,worker01,worker02]:8080