How to build a hello world docker image by docker file

First, create a `hello-world.js’ file

console.log("Hello World")

Then, create a Dockerfile in the same directory, the Dockerfile should look like that:

FROM ubuntu

RUN apt update && apt install nodejs -y

WORKDIR /app

COPY . .

CMD ["node", "/app/hello-would.js"]

FROM ubuntu means we ubuntu the ubuntu image as the base

RUN apt update && apt install nodejs -y means install nodejs into the ubuntu image

WORKDIR is used to define the working directory of a Docker container.

COPY . . is to copy the current directory(the hello-world.js) to the WORKDIR

CMD ["node", "/app/hello-would.js"] is the command to run after the image load.

Finally, Build the image

docker build -t {image name and version} .

-t is the tag for the image name and version, for example, etklam/hello_app:0.1

. is the Dockerfile directory