From f70fb0720d2a643905ba8263253b16b973f6bc36 Mon Sep 17 00:00:00 2001
From: Malfurious <m@lfurio.us>
Date: Sat, 8 Jun 2024 14:55:47 -0400
Subject: Create docker image and services

As hinted by the previous commit, the mailnode system is built in a
single docker image for simplicity.  Defining multiple Dockerfiles would
lead to many redundant tasks and be harder to maintain.  So a common
image for all services is built.

However, the compose file spawns a unique container for each service,
and communication occurs via the filesystem, through volumes.  Note also
that some fields in docker-compose.yml are required to be set by the
end-user.

The mail system is oriented around virtual users, so that nobody needs
their own unix system account.  However, best security practice is to
create a dedicated user to own the mails - this user shouldn't be used
for any other purpose.  For this, the Dockerfile creates the user
"vmailbox".

The reason for declaring port exposure for TCP/80 is to enable automated
TLS encryption with nginx-proxy-acme.  This port is not actually opened
by the compose file.

Signed-off-by: Malfurious <m@lfurio.us>
---
 Dockerfile | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Dockerfile

(limited to 'Dockerfile')

diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..7eafaf1
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,42 @@
+FROM debian
+
+ARG HOSTNAME
+ARG VIRTUAL_DOMAINS
+ENV DEBIAN_FRONTEND=noninteractive
+
+# Create system users with fixed, well-known UID/GIDs
+RUN useradd \
+    --uid 2000 --system \
+    --shell /usr/sbin/nologin \
+    --home-dir /var/mail/vhost \
+    --skel /dev/null --create-home \
+    vmailbox
+
+RUN useradd \
+    --uid 2001 --system \
+    --shell /usr/sbin/nologin \
+    --home-dir /var/spool/postfix \
+    postfix
+
+# Install packages
+RUN apt update \
+ && apt full-upgrade --yes \
+ && apt install --yes \
+    dovecot-core \
+    dovecot-imapd \
+    postfix \
+ && apt clean
+
+# Install files
+COPY dovecot /etc/dovecot/
+COPY postfix /etc/postfix/
+COPY userconfig /etc/userconfig/
+
+RUN find /etc/dovecot /etc/postfix -type f | xargs sed -i \
+    "s/ENV_HOSTNAME/${HOSTNAME}/g; s/ENV_VIRTUAL_DOMAINS/${VIRTUAL_DOMAINS}/g"
+
+EXPOSE 25
+EXPOSE 80
+EXPOSE 465
+EXPOSE 993
+# CMD set by docker-compose.yml
-- 
cgit v1.2.3