This image is based on Alpine Linux image, which is only a 5MB image, and contains glibc to enable proprietary projects compiled against glibc (e.g. OracleJDK, Anaconda) work on Alpine.
This image includes some quirks to make glibc work side by side with musl libc (default in Alpine Linux). glibc packages for Alpine Linux are prepared by Sasha Gerrand and the releases are published in sgerrand/alpine-pkg-glibc github repo.
This image is intended to be a base image for your projects, so you may use it like this:
FROM 4ops/alpine-glibc:3.9
COPY ./my_app /usr/local/bin/my_app$ docker build -t my_app .