What is the WORKDIR keyword in the Dockerfile

The WORKDIR is directory where you’ll do your RUN command or CMD command.

to find out, create the image with the simple Dockerfile below

FROM nginx:latest

WORKDIR /some/path/to/some/file/and/if/not/exists/it/will/create/it/
RUN touch create_a_file.md

when you do

docker container run -it mynginx bash

youl’ll find yourself in the directory /some/path/to/some/file/and/if/not/exists/it/will/create/it. and if you do ls, you’ll find there’s a file called create_a_file.md in the directory.

You can change the WORKDIR many times to preform different tasks in the Dockerfile.