Docker for beginners
docker pull [image name or url]
Pulls the docker image from the docker registry. The docker registry is similar to Github in that it hosts a bunch of docker images.
docker images to list all of the images on the local machine.
docker run [image name]
-ddetaches the terminal window from the running docker container.
-Ppublishes all exposed ports to random ports so that the application inside the container can be accessed. You can also specify which port to use with
docker run -p 8888:80 ....
--namegives the container a human readable name.
Runs a docker container based on the image that is passed in.
docker run -it [image name] attaches you to an interactive shell in the container itself.
docker stop [container ID or name]
Stops the running container when running in detached mode.
-ashows all containers that have been run.
Shows all of the containers that are currently running. Docker creates a new container everytime the command is run. That way the environment is always as you expect.
docker rm [container ID]
Container stick around on the disk even after they are no longer running and have a STATUS of
docker ps -a to get the container ID then run
docker rm [container ID], i.e.
docker rm 605982f999a1.
You can also pass in the
--rm flag during the
docker run command to delete the container after it’s been ran. i.e.
docker run --rm busybox echo "Hello".
docker container prune will delete all exited containers at once. This way you don’t need to copy and paste each container ID in the
docker rm command.
To get a list of containers use
docker ps for active containers or
docker ps -a for all containers that are currently running, exited, ect.
docker rmi [image name]
Deletes the docker image you no longer need.
To get the list of images use
Dockerfile reference: https://docs.docker.com/engine/reference/builder/
A Dockerfile is a text file that outlines what a docker image should look like. It contains a list of commands that docker uses to build and create an image which can later be used to create a container.
Creating a Dockerfile by just creating a new file named
Example Dockerfile I used from Docker for beginners
# Specify the base image first. FROM python:3 # Set a working directory for our app WORKDIR /usr/src/app # Copy all the files to the container COPY . . # Install Python dependencies using the requirements.txt file RUN pip install --no-cache-dir -r requirements.txt # Expose the port that the app will run on EXPOSE 5000 # Run the command for running the application CMD ["python", "./app.py"]
docker build [dockerhubUsername/image name] [location of Dockerfile]
-tto give the image a specific tag. Generally a version number.
docker build creates a docker image out of the Dockerfile. To add a tag the docker image use
:[tag name] after the image name,
docker build [dockerhubUsername/image name]:[tag name] [location of Dockerfile]
docker push [dockerhubUsername/image name]
Pushes the docker image to DockerHub.