What is Dockerfile, Docker Image and container ?
When I started reading about Docker, I was confused about the relationship between Docker file vs docker image vs docker container !
Short answer to my question is:
- Docker file is where I need to script my steps on what actions to be done before I make a docker image.
- A sample docker file as below:
- here below in the code, I am pulling JDK environment in line 1.
- copying a java class to app directory in line 2,
- setting app as working directory in line 3 for my docker container after i convert image to container.
- Then finally running my app in line 4.
COPY HelloWorl.class /app/
- Docker image is created using the above docker file by building it. (command : docker build -t myhelloworldapp . )
- then spin up the container by using command : docker run myhelloworldapp