add a script to move all logs to host

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

alpine/Dockerfile

@@ -40,6 +40,7 @@ COPY packages/dnsfix/etc /etc/
 COPY packages/database/etc /etc/
 COPY packages/hupper/hupper /bin/
 COPY packages/hupper/etc /etc/
+COPY packages/hostlog/etc /etc/
 
 RUN \
   rc-update add swap boot && \
@@ -75,6 +76,7 @@ RUN \
   rc-update add dnsfix boot && \
   rc-update add database boot && \
   rc-update add hupper default && \
+  rc-update add hostlog default && \
   ln -s /bin/busybox /init
 
 CMD ["/bin/sh"]

alpine/packages/docker/etc/init.d/docker

@@ -6,12 +6,6 @@ command="${DOCKER_BINARY:-/usr/bin/docker}"
 
 pidfile="/run/docker.pid"
 
-if cat /proc/cmdline | grep -q 'com.docker.groupDir'
-then
-	GROUPDIR="/Mac$(cat /proc/cmdline | sed -e 's/.*com.docker.groupDir="//' -e 's/".*//')"
-	[ -d "${GROUPDIR}" ] && DOCKER_LOGFILE="${GROUPDIR}/docker.log"
-fi
-
 if cat /proc/cmdline | grep -q 'com.docker.database'
 then
 	DATABASE="$(cat /proc/cmdline | sed -e 's/.*com.docker.database="//' -e 's/".*//')"
@@ -21,7 +15,8 @@ fi
 
 command_args="daemon -p \"${pidfile}\" ${DOCKER_OPTS}"
 
-DOCKER_LOGFILE="${DOCKER_LOGFILE:-/var/log/${RC_SVCNAME}.log}"
+DOCKER_LOGFILE="/var/log/docker.log}"
+
 start_stop_daemon_args="--background \
         --stderr \"${DOCKER_LOGFILE}\" --stdout \"${DOCKER_LOGFILE}\""
 

alpine/packages/hostlog/etc/init.d/hostlog

@@ -0,0 +1,19 @@
+#!/sbin/openrc-run
+
+depends()
+{
+	before acpid docker syslog chronyd
+	after 9pinit 9pudfuse
+}
+
+start()
+{
+	cat /proc/cmdline | grep -q 'com.docker.groupDir' || exit 0
+
+	ebegin "Redirecting logs to host"
+
+	GROUPDIR="/Mac$(cat /proc/cmdline | sed -e 's/.*com.docker.groupDir="//' -e 's/".*//')"
+
+	mount --bind "${GROUPDIR}" /var/log
+ 
+	eend $? "Failed to redirect logs to host"