How do I run composer with caddy-docker php?

```
FROM abiosoft/caddy:php-no-stats
RUN apk add --no-cache bash
WORKDIR /srv
RUN composer require aws/aws-sdk-php
RUN touch /srv/testing123
ADD Dockerfile /srv/just-testing
ENTRYPOINT ["bash"]
(ins)[hendry@t14s docker-sanity-test]$ make start
docker run --rm -it --name sanitytest $(whoami)/sanitytest
bash-5.0# ls /srv
index.php just-testing
```

For some reason I don't understand `/srv` files that composer creates are not set in the above case.