container
代码app，构建，运行，分享（推送）image
mkdir img1
cd img1
[root@cu-tmp-201 img1]# ls
app.py Dockerfile requirements.txt
--------------------------------------------------------
vi Dockerfile
# Use an official Python runtime as a parent image
FROM python:2.7-slim
# Set the working directory to /app
WORKDIR /app
# Copy the current directory contents into the container at /app
COPY . /app
# Install any needed packages specified in requirements.txt
RUN pip install --trusted-host pypi.python.org -r requirements.txt
# Make port 80 available to the world outside this container
EXPOSE 80
# Define environment variable
ENV NAME World
# Run app.py when the container launches
CMD ["python", "app.py"]
-------------------------------------------------------
vi requirements.txt
Flask
Redis
-------------------------------------------------------
vi 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 = "<i>cannot connect to Redis, counter disabled</i>"
html = "<h3>Hello {name}!</h3>"
"<b>Hostname:</b> {hostname}<br/>"
"<b>Visits:</b> {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=80)
==========================================
docker build -t=img1 .
docker build -t=img1:v0.01 .
docker build -t createyuan/my-first:a1 .
运行在前台
docker run -p 4000:80 img1
运行在后台
docker run -d -p 4000:80 img1
[root@cu-tmp-201 img1]# docker build -t=img1 .
Sending build context to Docker daemon 5.12kB
Step 1/7 : FROM python:2.7-slim
2.7-slim: Pulling from library/python
743f2d6c1f65: Pull complete
9bfbedfce8de: Pull complete
7f4da2474cef: Pull complete
ffc893575679: Pull complete
Digest: sha256:686bc67cbebf4c4fb0d96d55650d8704d00ccb6b9c6bdd0bee5fad48b827a6cb
Status: Downloaded newer image for python:2.7-slim
---> eb40dcfcbc42
Step 2/7 : WORKDIR /app
---> Running in bb3e3e32cc1f
Removing intermediate container bb3e3e32cc1f
---> bed29d83d8aa
Step 3/7 : COPY . /app
---> d189b5eac250
Step 4/7 : RUN pip install --trusted-host pypi.python.org -r requirements.txt
---> Running in 5e9d4ad3a252
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7.
Collecting Flask (from -r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/9a/74/670ae9737d14114753b8c8fdf2e8bd212a05d3b361ab15b44937dfd40985/Flask-1.0.3-py2.py3-none-any.whl (92kB)
Collecting Redis (from -r requirements.txt (line 2))
Downloading https://files.pythonhosted.org/packages/ac/a7/cff10cc5f1180834a3ed564d148fb4329c989cbb1f2e196fc9a10fa07072/redis-3.2.1-py2.py3-none-any.whl (65kB)
Collecting itsdangerous>=0.24 (from Flask->-r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/76/ae/44b03b253d6fade317f32c24d100b3b35c2239807046a4c953c7b89fa49e/itsdangerous-1.1.0-py2.py3-none-any.whl
Collecting Jinja2>=2.10 (from Flask->-r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/1d/e7/fd8b501e7a6dfe492a433deb7b9d833d39ca74916fa8bc63dd1a4947a671/Jinja2-2.10.1-py2.py3-none-any.whl (124kB)
Collecting Werkzeug>=0.14 (from Flask->-r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/9f/57/92a497e38161ce40606c27a86759c6b92dd34fcdb33f64171ec559257c02/Werkzeug-0.15.4-py2.py3-none-any.whl (327kB)
Collecting click>=5.1 (from Flask->-r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl (81kB)
Collecting MarkupSafe>=0.23 (from Jinja2>=2.10->Flask->-r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/fb/40/f3adb7cf24a8012813c5edb20329eb22d5d8e2a0ecf73d21d6b85865da11/MarkupSafe-1.1.1-cp27-cp27mu-manylinux1_x86_64.whl
Installing collected packages: itsdangerous, MarkupSafe, Jinja2, Werkzeug, click, Flask, Redis
Successfully installed Flask-1.0.3 Jinja2-2.10.1 MarkupSafe-1.1.1 Redis-3.2.1 Werkzeug-0.15.4 click-7.0 itsdangerous-1.1.0
Removing intermediate container 5e9d4ad3a252
---> 69c2d8844363
Step 5/7 : EXPOSE 80
---> Running in 24367df46ae6
Removing intermediate container 24367df46ae6
---> f3c8ef356dbc
Step 6/7 : ENV NAME World
---> Running in 2a234b7f8f21
Removing intermediate container 2a234b7f8f21
---> 9619ded601a9
Step 7/7 : CMD ["python", "app.py"]
---> Running in 03cbc7a6be80
Removing intermediate container 03cbc7a6be80
---> 5ff25ce7dd38
Successfully built 5ff25ce7dd38
Successfully tagged img1:latest
[root@cu-tmp-201 img1]# docker run -p 4000:80 img1
* Serving Flask app "app" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://0.0.0.0:80/ (Press CTRL+C to quit)
192.168.4.171 - - [19/May/2019 07:18:25] "GET / HTTP/1.1" 200 -
192.168.4.171 - - [19/May/2019 07:18:25] "GET /favicon.ico HTTP/1.1" 404 -
用浏览器或命令行来访问
[root@cu-tmp-201 ~]# curl http://localhost:4000
<h3>Hello World!</h3><b>Hostname:</b> ddafad51e416<br/><b>Visits:</b> <i>cannot connect to Redis, counter disabled</i>
ctrl+c之后，再次连接就报错
[root@cu-tmp-201 ~]# curl http://localhost:4000
curl: (7) Failed connect to localhost:4000; Connection refused
运行在后台
[root@cu-tmp-201 img1]# docker run -d -p 4000:80 img1
22cfe0d0d33bad99c403a785c5972cda33a9f422ca341568ce7320d79892ebef
[root@cu-tmp-201 img1]# docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
22cfe0d0d33b img1 "python app.py" 4 seconds ago Up 2 seconds 0.0.0.0:4000->80/tcp condescending_haibt
[root@cu-tmp-201 img1]# docker container stop 22cfe0d0d33b
22cfe0d0d33b
docker tag img1 createyuan/my-first:devapp
docker push createyuan/my-first:devapp
然后在任意机器上运行
docker run -d -p 4000:80 username/repository:tag
docker run -d -p 4000:80 createyuan/my-first:devapp
[root@cu-tmp-201 img1]# docker push createyuan/my-first:devapp
The push refers to repository [docker.io/createyuan/my-first]
6611f8494790: Pushed
f8b091cbf2de: Pushed
d570601a4e8e: Pushed
0ec0d723449a: Mounted from library/python
5c78e81a8fd9: Mounted from library/python
7b6b548a54d0: Mounted from library/python
6270adb5794c: Pushed
devapp: digest: sha256:85d48d62c2507a38bd5f2b63e069dac76ccf8fbea00c78f025b881d202cb0f5d size: 1788
scale application
services
single-host mode
分布式应用更上一层
server与service什么关系
scale application
在一个分布式应用中，不同的应用片（软件片）叫做服务
一个服务只运行一个镜像
Scaling a service changes the number of container instances running that piece of software, assigning more computing resources to the service in the process.
伸缩一个服务改变了软件片运行容器实例的数量，在进程中给服务分配更多的计算资源
Luckily it’s very easy to define, run, and scale services with the Docker platform -- just write a docker-compose.yml file.
幸运的是它非常简单来定义，运行，伸缩服务，用docker平台，只需编写compose.yml文件。
A single container running in a service is called a task.
----------------------------------------
vi docker-compose.yml
version: "3"
services:
web:
# replace username/repo:tag with your name and image details
image: createyuan/my-first:devapp
deploy:
replicas: 3
resources:
limits:
cpus: "0.1"
memory: 50M
restart_policy:
condition: on-failure
ports:
- "4000:80"
networks:
- webnet
networks:
webnet:
----------------------------------------
docker swarm init
docker stack deploy -c docker-compose.yml services-dist
docker service ls
[root@cu-tmp-201 img1]# docker swarm init
Swarm initialized: current node (bbc6waopcxs6pof5dr8zo568j) is now a manager.
To add a worker to this swarm, run the following command:
docker swarm join --token SWMTKN-1-3g4ucshflo3wz2hs9lrhuzcyl05gwyb1wocs86sc57p9k52f9k-664wc65rkdb2xat7utn21h5on 192.168.7.201:2377
To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.
[root@cu-tmp-201 img1]# docker stack deploy -c docker-compose.yml services-dist
Creating network services-dist_webnet
Creating service services-dist_web
[root@cu-tmp-201 img1]# docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
t7lnmbq9ktud services-dist_web replicated 3/3 createyuan/my-first:devapp *:4000->80/tcp
这两个是等效的
[root@cu-tmp-201 img1]# docker stack services services-dist
ID NAME MODE REPLICAS IMAGE PORTS
t7lnmbq9ktud services-dist_web replicated 3/3 createyuan/my-first:devapp *:4000->80/tcp
[root@cu-tmp-201 img1]# docker service ps t7lnmbq9ktud
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
zyabpseko53b services-dist_web.1 createyuan/my-first:devapp cu-tmp-201 Running Running 6 minutes ago
kgjp4l2bvz31 services-dist_web.2 createyuan/my-first:devapp cu-tmp-201 Running Running 6 minutes ago
re5a39l2fkdx services-dist_web.3 createyuan/my-first:devapp cu-tmp-201 Running Running 6 minutes ago
[root@cu-tmp-201 img1]# docker service ps services-dist_web
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
zyabpseko53b services-dist_web.1 createyuan/my-first:devapp cu-tmp-201 Running Running 6 minutes ago
kgjp4l2bvz31 services-dist_web.2 createyuan/my-first:devapp cu-tmp-201 Running Running 6 minutes ago
re5a39l2fkdx services-dist_web.3 createyuan/my-first:devapp cu-tmp-201 Running Running 6 minutes ago
[root@cu-tmp-201 img1]# docker stack ps services-dist
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
zyabpseko53b services-dist_web.1 createyuan/my-first:devapp cu-tmp-201 Running Running 12 minutes ago
kgjp4l2bvz31 services-dist_web.2 createyuan/my-first:devapp cu-tmp-201 Running Running 12 minutes ago
re5a39l2fkdx services-dist_web.3 createyuan/my-first:devapp cu-tmp-201 Running Running 12 minutes ago
curl -4 http://localhost:4000
可以看到id在变化，每次都不一样，在这三个当中轮流切换
也可以在浏览器中不停地刷新
vi docker-compose.yml
修改数量为2，保存，然后重新运行部署，就变成2个了，这样就达到的伸缩，扩大或缩小
docker stack deploy -c docker-compose.yml services-dist
docker container ls -q
[root@cu-tmp-201 img1]# docker stack deploy -c docker-compose.yml services-dist
Updating service services-dist_web (id: t7lnmbq9ktudyc47z9nv0q6u5)
image createyuan/my-first:devapp could not be accessed on a registry to record
its digest. Each node will access createyuan/my-first:devapp independently,
possibly leading to different nodes running different
versions of the image.
[root@cu-tmp-201 img1]# docker container ls -q
351caa4550f3
f109c78a62ab
=======================================
docker stack rm services-dist
docker swarm leave --force
[root@cu-tmp-201 img1]# docker stack rm services-dist
Removing service services-dist_web
Removing network services-dist_webnet
[root@cu-tmp-201 img1]# docker swarm leave --force
Node left the swarm.
swarm mode
一个服务多个容器，单机上 a single-host mode 多机，多容器，多个服务 swarm mode Swarm managers 使用一些策略来运行容器， 如空节点，用容器填充最少利用的机器 或global，简单说就是均分 在compose文件中指示manager来使用这些策略 https://docs.docker.com/engine/reference/commandline/service_ls/ The mode filter matches on the mode (either replicated or global) of a service. The following filter matches only global services. docker service ls --filter mode=global ingress n. 进入；入口；准许进入；入境
docker network create --help
--ingress Create swarm routing-mesh network
the app is deployed on a swarm cluster! You can access your app from the IP address of either 201 or 202. ========================================== base=https://github.com/docker/machine/releases/download/v0.16.0 && curl -L $base/docker-machine-$(uname -s)-$(uname -m) >/tmp/docker-machine && install /tmp/docker-machine /usr/local/bin/docker-machine ========================================== docker swarm init docker swarm join 在另外一台机器上运行下面的命令（由上面命令的输出结果而知） docker swarm join --token SWMTKN-1-0jj8wwym73oy4p99akpnqym51no7qff94ldv8zh392bs60gkhm-9x3p3dai7lity5c6iiu9lusrq 192.168.7.201:2377 docker node ls [root@cu-tmp-201 img1]# docker stack deploy -c docker-compose.yml services-dist Updating service services-dist_web (id: p8d20li46xa8pva4akdixlt6k) image createyuan/my-first:devapp could not be accessed on a registry to record its digest. Each node will access createyuan/my-first:devapp independently, possibly leading to different nodes running different versions of the image. 导致全部运行在一个节点 [root@cu-tmp-201 img1]# docker stack deploy --with-registry-auth -c docker-compose.yml services-dist Updating service services-dist_web (id: p8d20li46xa8pva4akdixlt6k) 这样就好了，加--with-registry-auth这个flag 或者 [root@cu-tmp-201 img1]# docker service update services-dist_web --with-registry-auth [root@cu-tmp-202 img2]# docker stack ps services-dist ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS mt1ma16gemko services-dist_web.1 createyuan/my-first:devapp cu-tmp-202 Running Running 15 minutes ago i2bo9odkuo1c services-dist_web.2 createyuan/my-first:devapp cu-tmp-201 Running Running 21 minutes ago j03od8elgw1o services-dist_web.3 createyuan/my-first:devapp cu-tmp-202 Running Running 15 minutes ago jwz23z137ewq services-dist_web.4 createyuan/my-first:devapp cu-tmp-201 Running Running 21 minutes ago
stack,其实从part3（即container部分），就开始使用stack了，添加多个服务到stack，依次为visualizer,redis
version: "3"
services:
web:
# replace username/repo:tag with your name and image details
image: createyuan/my-first:devapp
deploy:
replicas: 6
restart_policy:
condition: on-failure
resources:
limits:
cpus: "0.1"
memory: 50M
ports:
- "80:80"
networks:
- webnet
visualizer:
image: dockersamples/visualizer:stable
ports:
- "8080:8080"
volumes:
- "/var/run/docker.sock:/var/run/docker.sock"
deploy:
placement:
constraints: [node.role == manager]
networks:
- webnet
networks:
webnet:
docker-compose.yml这个文件中，不能有tab,而是用空格代替
[root@cu-tmp-202 img2]# docker stack deploy --with-registry-auth -c docker-compose.yml services-dist
yaml: line 19: found character that cannot start any token
修改之后，再次运行
[root@cu-tmp-202 img2]# docker stack deploy --with-registry-auth -c docker-compose.yml services-dist
Creating service services-dist_visualizer
Updating service services-dist_web (id: 93clo7n0xvg9op3i19qfej2xb)
[root@cu-tmp-202 img2]# docker stack ls
NAME SERVICES ORCHESTRATOR
services-dist 2 Swarm
[root@cu-tmp-202 img2]# docker stack ps services-dist
[root@cu-tmp-202 img2]# docker stack services services-dist
ID NAME MODE REPLICAS IMAGE PORTS
93clo7n0xvg9 services-dist_web replicated 6/6 createyuan/my-first:devapp *:80->80/tcp
mr26lixzk4wp services-dist_visualizer replicated 0/1 dockersamples/visualizer:stable *:8080->8080/tcp
可能要过一会，因为要下载visualizer image
也可独立部署visualizer
https://hub.docker.com/r/dockersamples/visualizer/
[root@cu-tmp-202 log]# docker stack services services-dist
ID NAME MODE REPLICAS IMAGE PORTS
93clo7n0xvg9 services-dist_web replicated 6/6 createyuan/my-first:devapp *:80->80/tcp
mr26lixzk4wp services-dist_visualizer replicated 1/1 dockersamples/visualizer:stable *:8080->8080/tcp
浏览器地址栏访问正常
http://192.168.7.202:8080/
再次加入新的服务redis
redis:
image: redis
ports:
- "6379:6379"
volumes:
- "/home/docker/data:/data"
deploy:
placement:
constraints: [node.role == manager]
command: redis-server --appendonly yes
networks:
- webnet
/home/docker/data
这是在host上建的目录，可以任意。
[root@cu-tmp-202 img2]# docker stack deploy --with-registry-auth -c docker-compose.yml services-dist
Creating service services-dist_redis
Updating service services-dist_web (id: 93clo7n0xvg9op3i19qfej2xb)
Updating service services-dist_visualizer (id: mr26lixzk4wpdmq5fu5ns6efa)
[root@cu-tmp-202 data]# docker stack services services-dist
ID NAME MODE REPLICAS IMAGE PORTS
93clo7n0xvg9 services-dist_web replicated 2/2 createyuan/my-first:devapp *:80->80/tcp
bv19yhv26y23 services-dist_redis replicated 1/1 redis:latest *:6379->6379/tcp
mr26lixzk4wp services-dist_visualizer replicated 1/1 dockersamples/visualizer:stable *:8080->8080/tcp
完毕，之前也一直存在这个问题，但没有解决，这次解决了
但存在一个问题，是有两个web，但始终只访问一个，不轮询。执行下面这个语句就可以了
[root@cu-tmp-202 data]# docker service update --with-registry-auth services-dist_web
services-dist_web
overall progress: 2 out of 2 tasks
1/2: running [==================================================>]
2/2: running [==================================================>]
verify: Service converged
[root@cu-tmp-202 data]#