Dockerfile

FROM alpine:3.16

# Mailcatcher version
ARG MAILCATCHER_VERSION=0.8.2

# Label
LABEL maintainer="spaquet74@gmail.com" \
    version="1.7.8" \
    description="Debug emails with style using mailcatcher a super simple SMTP server which catches messages sent to it and displays them in a web interface" \
    org.label-schema.name="mailcatcher" \
    org.label-schema.version="${MAILCATCHER_VERSION}" \
    org.label-schema.license="MIT"

# Setting the environment defaults to en_US.UTF-8
# --message-limit default value is 50
ENV LANG="en_US.UTF-8" \
    LC_ALL="en_US.UTF-8" \
    LANGUAGE="en_US.UTF-8" \
    TIMEZONE="UTC" \
    MAIL_LIMIT=50

RUN apk add --no-cache ruby \
    ruby-json sqlite-libs libstdc++ \
    ruby-dev make g++ sqlite-dev \
    && gem install --no-document --no-user-install net-smtp \
    && gem install -v $MAILCATCHER_VERSION mailcatcher --no-document \
    && apk del --rdepends --purge ruby-dev make g++ sqlite-dev \
    # && apk update && apk upgrade \
    && rm -rf /var/cache/apk/* /tmp/* /var/tmp/*

# expose smtp port & web port
EXPOSE 1025 1080

# launch mailcatcher as a foreground process
# Using sh to enable string interpolation
CMD ["sh", "-c", "mailcatcher --foreground --smtp-port=1025 --http-port=1080 --ip=0.0.0.0 --messages-limit=$MAIL_LIMIT"]