Redirect syslog to 'docker logs' and fix cron

Closes GH-123. Closes GH-115.

image/config/logrotate_syslogng

@@ -0,0 +1,38 @@
+/var/log/syslog
+{
+	rotate 7
+	daily
+	missingok
+	notifempty
+	delaycompress
+	compress
+	postrotate
+		sv reload syslog-ng > /dev/null
+	endscript
+}
+
+/var/log/mail.info
+/var/log/mail.warn
+/var/log/mail.err
+/var/log/mail.log
+/var/log/daemon.log
+/var/log/kern.log
+/var/log/auth.log
+/var/log/user.log
+/var/log/lpr.log
+/var/log/cron.log
+/var/log/debug
+/var/log/messages
+{
+	rotate 4
+	weekly
+	missingok
+	notifempty
+	compress
+	delaycompress
+	sharedscripts
+	postrotate
+		sv reload syslog-ng > /dev/null
+		sv restart cron-log-forwarder > /dev/null
+	endscript
+}

image/prepare.sh

@@ -45,3 +45,5 @@ apt-get dist-upgrade -y --no-install-recommends
 $minimal_apt_get_install language-pack-en
 locale-gen en_US
 update-locale LANG=en_US.UTF-8 LC_CTYPE=en_US.UTF-8
+echo -n en_US.UTF-8 > /etc/container_environment/LANG
+echo -n en_US.UTF-8 > /etc/container_environment/LC_CTYPE

image/runit/syslog-forwarder

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec tail -f -n 0 /var/log/syslog

image/system_services.sh

@@ -25,13 +25,19 @@ mkdir /etc/service/syslog-ng
 cp /build/runit/syslog-ng /etc/service/syslog-ng/run
 mkdir -p /var/lib/syslog-ng
 cp /build/config/syslog_ng_default /etc/default/syslog-ng
+touch /var/log/syslog
+chmod u=rw,g=r,o= /var/log/syslog
 # Replace the system() source because inside Docker we
 # can't access /proc/kmsg.
 sed -i -E 's/^(\s*)system\(\);/\1unix-stream("\/dev\/log");/' /etc/syslog-ng/syslog-ng.conf
 
+## Install syslog to "docker logs" forwarder.
+mkdir /etc/service/syslog-forwarder
+cp /build/runit/syslog-forwarder /etc/service/syslog-forwarder/run
+
 ## Install logrotate.
 $minimal_apt_get_install logrotate
-sed -i 's|invoke-rc.d syslog-ng reload|sv reload syslog-ng|g' /etc/logrotate.d/syslog-ng
+cp /build/config/logrotate_syslogng /etc/logrotate.d/syslog-ng
 
 ## Install the SSH server.
 $minimal_apt_get_install openssh-server
@@ -55,6 +61,7 @@ cp /build/bin/enable_insecure_key /usr/sbin/
 ## Install cron daemon.
 $minimal_apt_get_install cron
 mkdir /etc/service/cron
+chmod 600 /etc/crontab
 cp /build/runit/cron /etc/service/cron/run
 
 ## Remove useless cron entries.