Add Dockerfile for building docker images

Author: cmouse

Dockerfile

@@ -0,0 +1,8 @@
+FROM debian:13-slim AS base
+RUN apt update && apt install -y curl
+RUN curl -o /usr/local/bin/imaptest https://github.com/dovecot/imaptest/releases/download/latest/imaptest-$(uname -m)-debian-13
+RUN chmod +x /usr/local/bin/imaptest
+FROM debian:13-slim AS final
+COPY --link --from=base /usr/local/bin/imaptest /usr/local/bin/imaptest
+USER mail
+ENTRYPOINT ["/usr/local/bin/imaptest"]