UOCIS322 - Project 2

A "getting started with Docker" project in testium for CIS 322, Introduction to Software Engineering, at the University of Oregon.

For my specific project, I:

• Built the simple flask app image using

  docker build -t kaetlyng-cis322-2 .
  

• Ran the container using

  docker run -d -p port:5000 kaetlyng-cis322-2
  

NOTE: Make sure to specify a free port here.

• Launched http://hostname:port using my web browser and to check the output. Knowing the IPv4 address for eno2: 128.223.8.30, I used this as hostname for testing in testium rather than at my local machine at 0.0.0.0

Completed Tasks

• Implemented the same "file checking" logic that was implemented in Project 1, but using Flask.

• Like Project 1, if a file (name.html) exists, transmit 200/OK header followed by that file html. If the file doesn't exist, transmit an error code in the header along with the appropriate page html in the body by creating error handlers. Created the following two html files with the error messages:

  • 404.html will display "File not found!"
  • 403.html will display "File is forbidden!"

• Updated name and email in the Dockerfile.

Basic Docker commands

• Get information about docker setup the machine

  docker info
  

• List running docker containers

  docker ps
  

• List all docker containers

  docker ps -a
  

• List images using

  docker images
  

• Build an image

  docker build -t <Tag name> path/
  

  or just do this if your Dockerfile is in the same directory:

  docker build -t <Tag Name> .
  

• Remove containers

  docker container rm <Container Name>
  

• Run containers

  docker run <Tag Name / Image ID>
  

  docker run -h CONTAINER1 -i -t debian /bin/bash
  docker run -h CONTAINER1 -i -t ubuntu /bin/bash
  

  Here, -h is used to specify a container name, -t to start with tty, and -i means interactive. Note: second times will be quick because of caching.

• Docker with networking

  docker run -h CONTAINER2 -i -t --net="bridge" debian /bin/bash
  

• When the containers are not running and when you're done, kill them using

  docker rm `docker ps --no-trunc -aq`
  

• Rename using

  docker rename name_v0 name_v1
  

• Start a container

  docker start <container name>
  

• Stop a container

  docker stop <container name>
  

Creating images

• Create a Dockerfile. The name is case sensitive and it has to be Dockerfile

  vim Dockerfile
  

• The FROM command specifies the base image you are going to use. It can be an existing image, like ubuntu, alpine, debian, etc.

   FROM debian
  

• CMD command specifies all the commands you need to run

   CMD echo hello world
  

• Build the image with folder name (. in this case)

   docker build .
  

• Final output

  Successfully built e2e741ea5f6f  
  

• Run the image using the image ID (e2e741ea5f6f in this case) and a test name of your choice

  docker run --name <test name> e2e741ea5f6f
  

• Remove images using

  docker rmi <Image ID>
  

For more info refer to: https://docs.docker.com/engine/reference/builder/.

Credits

Michal Young, Ram Durairajan, Steven Walton, Joe Istas.