Passing folder as argument to a Docker container with the help of volumes-CodePudding

I have a python script that takes two arguments -input and -output and they are both directory paths. I would like to know first if this is a recommended use case of docker, and I would like to know also how to run the docker container by specifying custom input and output folders with the help of docker volume. My post is similar to this : Passing file as argument to Docker container. Still I was not able to solve the problem.

CodePudding user response：

Its common practice to use volumes to persist data or mount some input data. See the postgres image for example.

docker run -d \
  --name some-postgres \
  -e PGDATA=/var/lib/postgresql/data/pgdata \
  -v /custom/mount:/var/lib/postgresql/data \
  postgres

You can see how the path to the data dir is set via env var and then a volume is mounted at this path. So the produced data will end up in the volume.

You can also see in the docs that there is a directory /docker-entrypoint-initdb.d/ where you can mount input scripts, that run on first DB setup.

In your case it might look something like this.

docker run  \
  -v "$PWD/input:/app/input" \
  -v "$PWD/output:/app/output"  \
  myapp --input /app/input --output /app/output

Or you use the same volume for both.

docker run  \
  -v "$PWD/data:/app/data" \
  myapp --input /app/data/input --output /app/data/output