github repository: https://github.com/azzinoths0...
和集群相关的对象
SWARM
$ docker swarm --help
Usage: docker swarm COMMAND
Manage Swarm
Commands:
ca Display and rotate the root CA
init Initialize a swarm
join Join a swarm as a node and/or manager
join-token Manage join tokens
leave Leave the swarm
unlock Unlock swarm
unlock-key Manage the unlock key
update Update the swarm
Run 'docker swarm COMMAND --help' for more information on a command.创建swarm集群并启动manager：
docker swarm init --listen-addr 192.168.99.200:2377 --advertise-addr 192.168.99.200此时会输出加入swarm集群的方式：
docker swarm join --token SWMTKN-1-0nbwp5l3wsrtvf1hhrzf7dxbabpvitzo2ssyjqhnymg7d2ypzr-b1v1t5lnabvr4ojw9xe7eugkk 192.168.99.200:2377如果没有记住的话：
docker swarm join-token worker依旧会输出：
docker swarm join --token SWMTKN-1-0nbwp5l3wsrtvf1hhrzf7dxbabpvitzo2ssyjqhnymg7d2ypzr-b1v1t5lnabvr4ojw9xe7eugkk 192.168.99.200:2377在另一台节点上执行
docker swarm join --token SWMTKN-1-0nbwp5l3wsrtvf1hhrzf7dxbabpvitzo2ssyjqhnymg7d2ypzr-b1v1t5lnabvr4ojw9xe7eugkk 192.168.99.200:2377NODE
运行Docker的主机可以主动初始化一个Swarm集群或者加入一个已存在的Swarm集群，这样这个运行Docker的主机就成为一个Swarm集群的节点 (node) 。
$ docker node --help
Usage: docker node COMMAND
Manage Swarm nodes
Commands:
demote Demote one or more nodes from manager in the swarm
inspect Display detailed information on one or more nodes
ls List nodes in the swarm
promote Promote one or more nodes to manager in the swarm
ps List tasks running on one or more nodes, defaults to current node
rm Remove one or more nodes from the swarm
update Update a node
Run 'docker node COMMAND --help' for more information on a command.使用ls命令查看节点信息：
$ docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
v1oo73vt40hnjivnhnw78po4u * dameng-00 Ready Active Leader 18.09.8-ce
yrz7drszt4hq5j8c8rbhoexqc dameng-01 Ready Active 18.09.8-ceSTACK
Stack可以说是升级版的Compose：
$ docker stack --help
Usage: docker stack [OPTIONS] COMMAND
Manage Docker stacks
Options:
--kubeconfig string Kubernetes config file
--orchestrator string Orchestrator to use (swarm|kubernetes|all)
Commands:
deploy Deploy a new stack or update an existing stack
ls List stacks
ps List the tasks in the stack
rm Remove one or more stacks
services List the services in the stack部署：
# compose:
$ docker-compose -f CONFIG-YAML up
# stack:
$ docker stack deploy -c CONFIG-YAML STACK-NAME查看：
# compose:
$ docker-compose ps
$ docker ps
# stack:
$ docker node ls
$ docker stack ls
$ docker service ls终止：
# compose:
$ docker-compose -f CONFIG-YAML down
# stack:
$ docker stack rm STACK-NAME网络：
单机 vs 跨节点
注意: docker stack 默认使用的是swarm，但也是可以对接k8s的
SERVICE
$ docker service --help
Usage: docker service COMMAND
Manage services
Commands:
create Create a new service
inspect Display detailed information on one or more services
logs Fetch the logs of a service or task
ls List services
ps List the tasks of one or more services
rm Remove one or more services
rollback Revert changes to a service's configuration
scale Scale one or multiple replicated services
update Update a service
Run 'docker service COMMAND --help' for more information on a command.查看：
$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
oyiesfc3biiq myapp_myapp replicated 1/1 friendlyhello:v3 *:5000->5000/tcp
xrk7kska1z76 myapp_redis replicated 1/1 redis:latest扩容：
$ docker service scale myapp_myapp=2
ID NAME MODE REPLICAS IMAGE PORTS
oyiesfc3biiq myapp_myapp replicated 2/2 friendlyhello:v3 *:5000->5000/tcp
xrk7kska1z76 myapp_redis replicated 1/1 redis:latestTRY IT OUT: 部署friendlyhello
我们可以用Docker Machine 很快地创建一个虚拟的Docker主机，接下来我们来创建2个新的Docker主机，并加入到集群中。
STEP 1: 创建Swarm集群——管理节点
首先是一个管理节点，创建并通过ssh连接：
$ docker-machine create -d virtualbox manager
$ docker-machine ssh manager我们可以看到：
然后，我们用docker swarm init从这个节点初始化一个Swarm集群，如果这个Docker主机有多个IP（多个网卡），就要用--advertise-addr指定一个:
$ docker swarm init --advertise-addr 192.168.99.107我们可以看到：
现在我们的Manager节点就是刚刚创建的集群的管理节点了，
记得复制一下它输出的添加工作节点的那句命令。
STEP 2: 添加项目文件
接下来我们Manager节点的~/try-it-out-4里添加几个文件:
- app.py
- Dockerfile
- docker-stack.yaml
$ mkdir try-it-out-4
$ cd try-it-out-4
$ vi app.py
$ vi Dockerfile
$ vi docker-stack.yaml
$ docker build -t friendlyhello .
app.py
from flask import Flask
from redis import Redis, RedisError
import os
import socket
# Connect to Redis
redis = Redis(host="redis", db=0, socket_connect_timeout=2, socket_timeout=2)
app = Flask(__name__)
@app.route("/")
def hello():
try:
visits = redis.incr("counter")
except RedisError:
visits = "cannot connect to Redis, counter disabled"
html = "Hello {name}!
" \
"Hostname: {hostname}
" \
"Visits: {visits}"
return html.format(name=os.getenv("NAME", "world"), hostname=socket.gethostname(), visits=visits)
if __name__ == "__main__":
app.run(host='0.0.0.0', port=5000)Dockerfile
FROM python:3.7-slim
WORKDIR /app
COPY . /app
RUN pip install flask redis -i https://mirrors.aliyun.com/pypi/simple --trusted-host mirrors.aliyun.com
EXPOSE 5000
ENV NAME World
CMD ["python", "app.py"]docker-stack.yaml
version: "3"
services:
myapp:
image: friendlyhello
container_name: myapp
ports:
- 5000:5000
environment:
NAME: World
redis:
image: redis
container_name: webSTEP 3: 创建Swarm集群——工作节点
继续，我们来创建一个工作节点：
首先回到主机：
$ exit 接着创建一个新的虚拟机worker，并通过上面复制的那句命令加入到集群里:
$ docker-machine create -d virtualbox worker
$ docker-machine ssh worker
$ docker swarm join --token SWMTKN-1-3wd0vdozskitmpw5vofkjc9ie6251wuno21dmbugqk56pd97iv-eu9w5gkkmy7chvgcwt7j71iu4 192.168.99.107:2377我们可以看到：
STEP 4: 使用Stack部署服务
我们先回到manager节点：
$ exit
$ docker-machine ssh manager然后使用docker stack deploy部署服务，其中-c参数指定docker-stack.yaml文件：
$ docker stack deploy -c ~/try-it-out/docker-stack.yaml friendlyhello
部署完毕。
STEP 5: 访问friendlyhello
现在就可以通过集群中的任意一个节点的IP访问到这个flask项目了：
TRY IT OUT: 部署postgresql
我们继续用前一个Case的集群。
进入manager节点，在try-it-out-5里新建一个docker-stack.yaml：
$ docker-machine ssh manager
$ mkdir try-it-out-5
$ vi docker-stack.yamldocker-stack.yaml
version: '3.1'
services:
db:
image: postgres
command: postgres -c 'shared_buffers=512MB' -c 'max_connections=2000'
restart: always
environment:
POSTGRES_USER: dameng
POSTGRES_PASSWORD: pythonic
ports:
- 5432:5432
volumes:
- pgdata:/var/lib/postgresql/data
adminer:
image: adminer
restart: always
ports:
- 8998:8080
volumes:
pgdata:然后部署：
$ docker stack deploy -c docker-stack.yaml postgresql接着就可以从8998端口访问GUI了：
