From e979743226768c14aba3b366a7bd064013ff2dd7 Mon Sep 17 00:00:00 2001
From: Michael Wyraz <michael@wyraz.de>
Date: Thu, 9 Apr 2020 14:34:54 +0200
Subject: [PATCH] Rsyslog logging for postfix, optional logging to file, no
 logging of test requests

---
 core/postfix/Dockerfile        |  2 +-
 core/postfix/conf/main.cf      |  3 ---
 core/postfix/conf/rsyslog.conf | 40 ++++++++++++++++++++++++++++++++++
 core/postfix/start.py          |  6 +++++
 docs/configuration.rst         |  3 +++
 5 files changed, 50 insertions(+), 4 deletions(-)
 create mode 100644 core/postfix/conf/rsyslog.conf

diff --git a/core/postfix/Dockerfile b/core/postfix/Dockerfile
index af29bf91..0c7e136d 100644
--- a/core/postfix/Dockerfile
+++ b/core/postfix/Dockerfile
@@ -12,7 +12,7 @@ RUN pip3 install socrate==0.2.0
 RUN pip3 install "podop>0.2.5"
 
 # Image specific layers under this line
-RUN apk add --no-cache postfix postfix-pcre cyrus-sasl-plain cyrus-sasl-login
+RUN apk add --no-cache postfix postfix-pcre cyrus-sasl-plain rsyslog cyrus-sasl-login
 
 COPY conf /conf
 COPY start.py /start.py
diff --git a/core/postfix/conf/main.cf b/core/postfix/conf/main.cf
index 8f35f609..10143f29 100644
--- a/core/postfix/conf/main.cf
+++ b/core/postfix/conf/main.cf
@@ -2,9 +2,6 @@
 # General
 ###############
 
-# Logging configuration
-maillog_file = /dev/stdout
-
 # Main domain and hostname
 mydomain = {{ DOMAIN }}
 myhostname = {{ HOSTNAMES.split(",")[0] }}
diff --git a/core/postfix/conf/rsyslog.conf b/core/postfix/conf/rsyslog.conf
new file mode 100644
index 00000000..d8a7bdf4
--- /dev/null
+++ b/core/postfix/conf/rsyslog.conf
@@ -0,0 +1,40 @@
+# rsyslog configuration file
+#
+# For more information see /usr/share/doc/rsyslog-*/rsyslog_conf.html
+# or latest version online at http://www.rsyslog.com/doc/rsyslog_conf.html
+# If you experience problems, see http://www.rsyslog.com/doc/troubleshoot.html
+
+
+#### Global directives ####
+
+# Sets the directory that rsyslog uses for work files.
+$WorkDirectory /var/lib/rsyslog
+
+# Sets default permissions for all log files.
+$FileOwner root
+$FileGroup adm
+$FileCreateMode 0640
+$DirCreateMode 0755
+$Umask 0022
+
+# Reduce repeating messages (default off).
+$RepeatedMsgReduction on
+
+
+#### Modules ####
+
+# Provides support for local system logging (e.g. via logger command).
+module(load="imuxsock")
+
+#### Rules ####
+
+# Discard messages from local test requests
+:msg, contains, "connect from localhost[127.0.0.1]"  ~
+
+{% if POSTFIX_LOG_FILE %}
+# Log mail logs to file
+mail.*							-{{LOG_FILE}}
+{% endif %}
+
+# Log mail logs to stdout
+mail.*							-/dev/stdout
diff --git a/core/postfix/start.py b/core/postfix/start.py
index b68303e1..d942c8f1 100755
--- a/core/postfix/start.py
+++ b/core/postfix/start.py
@@ -37,6 +37,9 @@ os.environ["ADMIN_ADDRESS"] = system.get_host_address_from_environment("ADMIN",
 os.environ["ANTISPAM_MILTER_ADDRESS"] = system.get_host_address_from_environment("ANTISPAM_MILTER", "antispam:11332")
 os.environ["LMTP_ADDRESS"] = system.get_host_address_from_environment("LMTP", "imap:2525")
 
+conf.jinja("/conf/rsyslog.conf", os.environ, "/etc/rsyslog.conf")
+
+
 for postfix_file in glob.glob("/conf/*.cf"):
     conf.jinja(postfix_file, os.environ, os.path.join("/etc/postfix", os.path.basename(postfix_file)))
 
@@ -61,6 +64,9 @@ if "RELAYUSER" in os.environ:
     conf.jinja("/conf/sasl_passwd", os.environ, path)
     os.system("postmap {}".format(path))
 
+# Start rsyslog
+os.system("/usr/sbin/rsyslogd -n &")
+
 # Run Podop and Postfix
 multiprocessing.Process(target=start_podop).start()
 os.system("/usr/libexec/postfix/post-install meta_directory=/etc/postfix create-missing")
diff --git a/docs/configuration.rst b/docs/configuration.rst
index 5ff3546a..78d147fa 100644
--- a/docs/configuration.rst
+++ b/docs/configuration.rst
@@ -147,6 +147,9 @@ Log messages equal or higher than this priority will be printed.
 Can be one of: CRITICAL, ERROR, WARNING, INFO, DEBUG or NOTSET.
 See the `python docs`_ for more information.
 
+``POSTFIX_LOG_FILE`` enables postfix logging to the given file (in addition to log to stdout).
+Log rotation should be done externally.
+
 .. _`python docs`: https://docs.python.org/3.6/library/logging.html#logging-levels
 
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