Managing Docker containers

Tested Infrastructure

Platform	Number of Instance	Reading Time
Play with Docker	1	5 min

Pre-requisite

• Create an account with DockerHub
• Open PWD Platform on your browser
• Click on Add New Instance on the left side of the screen to bring up Alpine OS instance on the right side

Preparations

• Clean your docker host using the commands (in bash):

$ docker rm -f $(docker ps -a -q)

Instructions

• Run the following containers from the dockerhub:

  $ docker run -d -p 5000:5000 --name app1 selaworkshops/python-app:1.0
  

  $ docker run -d -p 5001:5001 -e "port=5001" --name app2 selaworkshops/python-app:2.0
  

• Ensure the containers are running:

  $ docker ps
  

• Stop the first container:

  $ docker stop app1
  

• Kill the second container:

  $ docker kill app2
  

• Display running containers:

  $ docker ps
  

• Show all the containers (includind non running containers):

  $ docker ps -a
  

• Let’s start both containers again:

  $ docker start app1 app2
  

• Restart the second container:

  $ docker restart app2
  

• Display the docker host information with:

  $ docker info
  

• Show the running processes in the first container using:

  $ docker top app1
  

• Retrieve the history of the second container:

  $ docker history selaworkshops/python-app:2.0
  

• Inspect the second container image:

  $ docker inspect selaworkshops/python-app:2.0
  

• Inspect the first container and look for the internal ip:

  $ docker inspect app1
  

  "Networks": {
               "bridge": {
                   "IPAMConfig": null,
                   "Links": null,
                   "Aliases": null,
                   "NetworkID": "822cb66790c6358d9decab874916120f3bdeff7193a4375c94ca54d50832303d",
                   "EndpointID": "9aa96dc29be08eddc6d8f429ebecd2285c064fda288681a3611812413cbdfc1f",
                   "Gateway": "172.17.0.1",
                   "IPAddress": "172.17.0.3",
                   "IPPrefixLen": 16,
                   "IPv6Gateway": "",
                   "GlobalIPv6Address": "",
                   "GlobalIPv6PrefixLen": 0,
                   "MacAddress": "02:42:ac:11:00:03",
                   "DriverOpts": null
               }
           }
  

• Show the logs of the second container using the flag –follow:

  $ docker logs --follow app2
  

• Browse to the application and see the containers logs from the terminal:

  http://localhost:5001
  

• Stop to tracking logs:

  $ CTRL + C
  

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