前言
接上篇，我们已经把docker的环境搭建完毕。下面将按官网的教程进行相关的入门操手。官网的教程地址：Get Started, Part 2: Containers
Dockerfilew配置容器
- 在宿主机上建立一个目录 如demo-docker
- cd demo-docker
- vi Dockerfile
- 在文件中录入如下内容：
# Use an official Python runtime as a parent image
# 我们使用官方提供的Python运行库作为父镜像
FROM python:2.7-slim
# Set the working directory to /app
# 设置工程目录路径 /app
WORKDIR /app
# Copy the current directory contents into the container at /app
# 复制当前文件夹下的文件到工程路径 /app下
ADD . /app
# Install any needed packages specified in requirements.txt
# 安装在requirements.txt中列出的依赖包
RUN pip install --trusted-host pypi.python.org -r requirements.txt
# Make port 80 available to the world outside this container
# 对外暴露本容器80端口
EXPOSE 80
# Define environment variable
# 定义环境变量
ENV NAME World
# Run app.py when the container launches
# 当容器运行时，执行的命令
CMD ["python", "app.py"]
- vi requirements.txt，并录入如下内容
Flask
Redis
- vi app.py 并录入如下内容
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)
- 最后在demo-docker中将有如下文件
app.py Dockerfile requirements.txt
- 创建docker镜像
docker build -t demo-docker .
- 运行完毕后，我们查看一下系统存在的docker镜像
docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
demo-docker latest 321a0064dbe2 About an hour ago 148MB
python 2.7-slim b0259cf63993 7 days ago 138MB
hello-world latest 725dcfab7d63 8 days ago 1.84kB
- 运行我们的镜像
# 将本机的4000端口映射到容器的80端口
docker run -p 4000:80 demo-docker
- 在后台运行
docker run -d -p 4000:80 demo-docker
- 启动后我们将得到容器的ID信息，停止的时候，我们将会使用到此ID.另外我们还可以通过命令来查看相关的ID
docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
83dd2473dc19 demo-docker "python app.py" 7 seconds ago Up 6 seconds 0.0.0.0:4000->80/tcp pensive_yalow
- 停止在后台运行的容器
docker container stop 83dd2473dc19
- docker的一些常用命令
docker build -t friendlyname . # Create image using this directory's Dockerfile
docker run -p 4000:80 friendlyname # Run "friendlyname" mapping port 4000 to 80
docker run -d -p 4000:80 friendlyname # Same thing, but in detached mode
docker container ls # List all running containers
docker container ls -a # List all containers, even those not running
docker container stop <hash> # Gracefully stop the specified container
docker container kill <hash> # Force shutdown of the specified container
docker container rm <hash> # Remove specified container from this machine
docker container rm $(docker container ls -a -q) # Remove all containers
docker image ls -a # List all images on this machine
docker image rm <image id> # Remove specified image from this machine
docker image rm $(docker image ls -a -q) # Remove all images from this machine
docker login # Log in this CLI session using your Docker credentials
docker tag <image> username/repository:tag # Tag <image> for upload to registry
docker push username/repository:tag # Upload tagged image to registry
docker run username/repository:tag # Run image from a registry
一些常见问题
# 当因网络问题，安装一些依赖失败的时候，会发现Docker的镜像并没有构建完成，而且在
docker image ls
中可看到相关的信息。
此时，我们先运行
docker ps -a
如果存在容器，则先把容器给删除掉
docker rm <cotainerID>
再执行
docker rmi <imageID>
