Adding the configuration change for multiple provider, Making the service run in foreground and adding test

Dockerfile

@@ -1,67 +1,58 @@
-#Postfix relay
-FROM docker.io/library/alpine:latest
+FROM docker.io/library/alpine:3.19
 
-#     Variables for Labels:
-ARG VENDOR="k2patel"
+# Variables for Labels
+ARG VENDOR="your-org"
 ARG COMPONENT="postfix-relay"
 ARG BUILD_DATE
-ARG GIT_REPO
+ARG GIT_REPO="https://github.com/your-org/docker-postfix"
 ARG VCS_REF
-ARG VERSION="1"
+ARG VERSION="2.0"
 ARG NAME="dockerized-${COMPONENT}"
-ARG DESCRIPTION="dockerized environment."
-ARG DOCUMENTATION="https://git.k2patel.in"
-ARG AUTHOR="k2patel<k2patel@live.com>"
+ARG DESCRIPTION="Postfix SMTP relay supporting multiple providers (Maileroo, Mailtrap, SendGrid)"
+ARG DOCUMENTATION="https://github.com/your-org/docker-postfix"
+ARG AUTHOR="Your Name <your-email@example.com>"
 ARG LICENSE="MIT"
-#     END Variables
 
-#########################################
+# Labels
 LABEL org.label-schema.build-date="${BUILD_DATE}" \
-        org.label-schema.name="${NAME}" \
-        org.label-schema.description="${DESCRIPTION}" \
-        org.label-schema.vcs-ref="${VCS_REF}" \
-        org.label-schema.vcs-url="${GIT_REPO}" \
-        org.label-schema.url="${GIT_REPO}" \
-        org.label-schema.vendor="${VENDOR}" \
-        org.label-schema.version="${VERSION}" \
-        org.label-schema.usage="${DOCUMENTATION}"
+    org.label-schema.name="${NAME}" \
+    org.label-schema.description="${DESCRIPTION}" \
+    org.label-schema.vcs-ref="${VCS_REF}" \
+    org.label-schema.vcs-url="${GIT_REPO}" \
+    org.label-schema.vendor="${VENDOR}" \
+    org.label-schema.version="${VERSION}"
 
-LABEL   org.opencontainers.image.created="${BUILD_DATE}" \
-        org.opencontainers.image.url="${GIT_REPO}" \
-        org.opencontainers.image.source="${GIT_REPO}" \
-        org.opencontainers.image.version="${VERSION}" \
-        org.opencontainers.image.revision="${VCS_REF}" \
-        org.opencontainers.image.vendor="${VENDOR}" \
-        org.opencontainers.image.title="${NAME}" \
-        org.opencontainers.image.description="${DESCRIPTION}" \
-        org.opencontainers.image.documentation="${DOCUMENTATION}" \
-        org.opencontainers.image.authors="${AUTHOR}" \
-        org.opencontainers.image.licenses="${LICENSE}"
-#########################################
+# Install required packages
+RUN apk add --no-cache \
+    postfix \
+    postfix-pcre \
+    cyrus-sasl \
+    cyrus-sasl-login \
+    libsasl \
+    ca-certificates \
+    bash \
+    tzdata \
+    mailx
 
-ENV TIMEZONE=${TIMEZONE}
-ENV SMTP_SERVER=${SMTP_SERVER}
-ENV SERVER_HOSTNAME=${SERVER_HOSTNAME}
-ENV SMTP_PORT=${SMTP_PORT}
-ENV DOMAIN=${DOMAIN}
-ENV SMTP_USERNAME=${SMTP_USERNAME}
-ENV SMTP_PASSWORD=${SMTP_PASSWORD}
+# Create necessary directories
+RUN mkdir -p /var/spool/postfix /etc/postfix/sasl
 
-# Intall Needed Package
-RUN apk add --no-cache postfix libsasl supervisor ca-certificates bash rsyslog cyrus-sasl
-
-#Configure nodaemon mode for supervisord
-RUN sed -i -e "s/^nodaemon=false/nodaemon=true/" /etc/supervisord.conf
-#Change postfix to listen on all the interface
-RUN sed -i -e 's/inet_interfaces = localhost/inet_interfaces = all/g' /etc/postfix/main.cf
-
-COPY etc/ /etc/
-VOLUME ["/var/log", "/var/mail", "/var/spool/postfix"]
-COPY run.sh /
+# Copy entrypoint script
+COPY run.sh /run.sh
 RUN chmod +x /run.sh
+
+# Initialize postfix
 RUN newaliases
 
+# Expose SMTP port
 EXPOSE 25
 
-ENTRYPOINT /usr/bin/supervisord -c /etc/supervisor/supervisord.conf
+# Volumes for persistence
+VOLUME ["/var/spool/postfix"]
 
+# Health check
+HEALTHCHECK --interval=30s --timeout=10s --retries=3 --start-period=40s \
+    CMD postfix status || exit 1
+
+# Run postfix in foreground
+ENTRYPOINT ["/run.sh"]