docker-容器完整構建過程

時間 2019-12-07

原文原文鏈接

containerhtml

代碼app，構建，運行，分享（推送）imagenode

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 .

運行在前臺
docker run -p 4000:80 img1
運行在後臺
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 -

用瀏覽器或命令行來訪問
[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以後，再次鏈接就報錯

[root@cu-tmp-201 ~]# curl http://localhost:4000
curl: (7) Failed connect to localhost:4000; Connection refused

運行在後臺
[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

而後在任意機器上運行
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 applicationpython

serviceslinux

single-host modegit

分佈式應用更上一層

server與service什麼關係
scale application

在一個分佈式應用中，不一樣的應用片（軟件片）叫作服務
一個服務只運行一個鏡像

Scaling a service changes the number of container instances running that piece of software, assigning more computing resources to the service in the process.
伸縮一個服務改變了軟件片運行容器實例的數量，在進程中給服務分配更多的計算資源
Luckily it’s very easy to define, run, and scale services with the Docker platform -- just write a docker-compose.yml file.
幸運的是它很是簡單來定義，運行，伸縮服務，用docker平臺，只需編寫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
這兩個是等效的
[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
能夠看到id在變化，每次都不同，在這三個當中輪流切換
也能夠在瀏覽器中不停地刷新


vi docker-compose.yml
修改數量爲2，保存，而後從新運行部署，就變成2個了，這樣就達到的伸縮，擴大或縮小
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 modegithub

一個服務多個容器，單機上
a single-host mode 

多機，多容器，多個服務
swarm mode

Swarm managers 使用一些策略來運行容器，
如空節點，用容器填充最少利用的機器
或global，簡單說就是均分
在compose文件中指示manager來使用這些策略

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. 進入；入口；准許進入；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
在另一臺機器上運行下面的命令（由上面命令的輸出結果而知）
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.

致使所有運行在一個節點

[root@cu-tmp-201 img1]# docker stack deploy --with-registry-auth -c docker-compose.yml services-dist
Updating service services-dist_web (id: p8d20li46xa8pva4akdixlt6k)

這樣就行了，加--with-registry-auth這個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,其實從part3（即container部分），就開始使用stack了，添加多個服務到stack，依次爲visualizer,redisweb

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這個文件中，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
修改以後，再次運行
[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

可能要過一會，由於要下載visualizer image
也可獨立部署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

瀏覽器地址欄訪問正常
http://192.168.7.202:8080/

再次加入新的服務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
這是在host上建的目錄，能夠任意。  
 
[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


完畢，以前也一直存在這個問題，但沒有解決，此次解決了
但存在一個問題，是有兩個web，但始終只訪問一個，不輪詢。執行下面這個語句就能夠了

[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]#