Install docker-ce on Centos 7

Uninstall old versions

$ sudo yum remove docker \                  docker-common \                  docker-selinux \                  docker-engine

Install using repository

sudo yum install -y yum-utils device-mapper-persistent-data lvm2sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.reposudo yum install docker-cesudo systemctl start dockersudo docker run hello-world

sudo systemctl status docker.service

sudo systemctl stop docker

sudo yum remove docker-ce

sudo rm -rf /var/lib/docker

Build/Run a simple python+flask docker web app

Create the Dockerfile

FROM python:2.7# Creating Application Source Code DirectoryRUN mkdir -p /usr/src/app# Setting Home Directory for containersWORKDIR /usr/src/app# Installing python dependenciesCOPY requirements.txt /usr/src/app/RUN pip install --no-cache-dir -r requirements.txt# Copying src code to ContainerCOPY . /usr/src/app# Application Environment variables#ENV APP_ENV developmentENV PORT 8080# Exposing PortsEXPOSE $PORT# Setting Persistent dataVOLUME ["/app-data"]# Running Python ApplicationCMD gunicorn -b :$PORT -c gunicorn.conf.py main:app

Build your image

sudo docker build -t my-python-app:1.0.1 .

check all docker images

$ sudo docker imagesREPOSITORY              TAG                 IMAGE ID            CREATED             SIZEmy-python-app           1.0.1               2b628d11ba3a        22 minutes ago      701.6 MBdocker.io/python        2.7                 b1d5c2d7dda8        13 days ago         679.3 MBdocker.io/hello-world   latest              05a3bd381fc2        5 weeks ago         1.84 kB

sudo docker tag 2b628d11ba3a my-python-app:1.0.1sudo docker tag 2b628d11ba3a my-python-app:latest

$ sudo docker rmi --force 2b628d11ba3a

Run your image

$ sudo docker run -d -p 8080:8080 my-python-app:1.0.1

$ sudo docker psCONTAINER ID        IMAGE                 COMMAND                  CREATED             STATUS              PORTS                    NAMES4de6041072b7        my-python-app:1.0.1   "/bin/sh -c 'gunicorn"   20 minutes ago      Up 20 minutes       0.0.0.0:8080->8080/tcp   elegant_kowalevski

$ sudo docker logs 4de6041072b7[2017-10-23 20:29:49 +0000] [7] [INFO] Starting gunicorn 19.6.0[2017-10-23 20:29:49 +0000] [7] [INFO] Listening at: http://0.0.0.0:8080 (7)[2017-10-23 20:29:49 +0000] [7] [INFO] Using worker: gthread[2017-10-23 20:29:49 +0000] [11] [INFO] Booting worker with pid: 11[2017-10-23 20:29:49 +0000] [12] [INFO] Booting worker with pid: 12

$ sudo docker stop 4de6041072b7

$ sudo docker exec -it 4de6041072b7 /bin/sh# ls /usr/src/appDockerfile  README.md  gunicorn.conf.py  gunicorn_pid.txt  main.py  main.pyc  requirements.txt# exit

Test your application

$ curl http://localhost:8080Hello World