How to pass arguments to an external file in Docker?

Question

linux

I have an executable program in Docker that needs to be passed arguments to parse a file (read-only). Similar to the file program.
Started with this Dockerfile

FROM alpine:3.7
ADD ./trid /usr/local/bin

How to do it?

Answer 1

If /usr/local/bin/trid is defined as ENTRYPOINT then CMD will be provided as options for ENTRYPOINT.
When starting the container, you can override CMD, in our case, specify the path to the file for analysis inside the container.
Therefore, you need to mount the external folder with files into the container.
# dockerfile

---
FROM alpine:3.7
ADD ./trid /usr/local/bin
ENTRYPOINT ["/usr/local/bin/trid"]
---

docker build -t trid:v1 .

# Files for analysis on host system

/var/lib/docker_data/files/file1.txt
/var/lib/docker_data/files/file2.txt
/var/lib/docker_data/files/file3.txt

# Running container for analysis file1.txt

docker run --rm -v /var/lib/docker_data/files:/data:ro --name analysis trid:v1 "/data/file1.txt"

Answer 2

You need to use ENTRYPOINT
https://riptutorial.com/en/docker/example/2700/%D1...