syslog changes Multi ASIC platforms (#4738)

Add changes for syslog support for containers running in namespaces on multi ASIC platforms.
On Multi ASIC platforms

Rsyslog service is only running on the host. There is no rsyslog service running in each namespace.
On multi ASIC platforms the rsyslog service on the host will be listening on the docker0 ip address instead of loopback address.
The rsyslog.conf on the containers is modified to have omfwd target ip to be docker0 ipaddress instead of loopback ip

Signed-off-by: Arvindsrinivasan Lakshmi Narasimhan <arlakshm@microsoft.com>

files/build_templates/docker_image_ctl.j2

@@ -27,6 +27,22 @@ link_namespace() {
 }
 {%- endif %}
 
+function updateSyslogConf()
+{
+    # On multiNPU platforms, change the syslog target ip to docker0 ip to allow logs from containers
+    # running on the namespace to reach the rsyslog service running on the host
+    # Also update the container name  
+    if [[ ($NUM_ASIC -gt 1) ]]; then
+        TARGET_IP=$(docker network inspect bridge --format={{ "'{{(index .IPAM.Config 0).Gateway}}'" }})
+        CONTAINER_NAME="{{docker_container_name}}$DEV"
+        TMP_FILE="/tmp/rsyslog.$CONTAINER_NAME.conf"
+
+        sonic-cfggen -t /usr/share/sonic/templates/rsyslog-container.conf.j2 -a "{\"target_ip\": \"$TARGET_IP\", \"container_name\": \"$CONTAINER_NAME\" }"  > $TMP_FILE
+        docker cp $TMP_FILE {{docker_container_name}}$DEV:/etc/rsyslog.conf
+        rm -rf $TMP_FILE
+    fi
+}
+
 function getMountPoint()
 {
     echo $1 | python -c "import sys, json, os; mnts = [x for x in json.load(sys.stdin)[0]['Mounts'] if x['Destination'] == '/usr/share/sonic/hwsku']; print '' if len(mnts) == 0 else os.path.basename(mnts[0]['Source'])" 2>/dev/null
@@ -68,6 +84,7 @@ function preStartAction()
 {%- else %}
     : # nothing
 {%- endif %}
+    updateSyslogConf
 }
 
 function postStartAction()

files/build_templates/sonic_debian_extension.j2

@@ -209,6 +209,7 @@ echo "warmboot-finalizer.service" | sudo tee -a $GENERATED_SERVICE_FILE
 sudo cp $IMAGE_CONFIGS/rsyslog/rsyslog-config.service $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_SYSTEM
 sudo cp $IMAGE_CONFIGS/rsyslog/rsyslog-config.sh $FILESYSTEM_ROOT/usr/bin/
 sudo cp $IMAGE_CONFIGS/rsyslog/rsyslog.conf.j2 $FILESYSTEM_ROOT_USR_SHARE_SONIC_TEMPLATES/
+sudo cp $IMAGE_CONFIGS/rsyslog/rsyslog-container.conf.j2 $FILESYSTEM_ROOT_USR_SHARE_SONIC_TEMPLATES/
 sudo cp $IMAGE_CONFIGS/rsyslog/rsyslog.d/* $FILESYSTEM_ROOT/etc/rsyslog.d/
 echo "rsyslog-config.service" | sudo tee -a $GENERATED_SERVICE_FILE
 

files/image_config/rsyslog/rsyslog-config.sh

@@ -1,4 +1,23 @@
 #!/bin/bash
 
-sonic-cfggen -d -t /usr/share/sonic/templates/rsyslog.conf.j2 >/etc/rsyslog.conf
+PLATFORM=`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`
+
+# Parse the device specific asic conf file, if it exists
+ASIC_CONF=/usr/share/sonic/device/$PLATFORM/asic.conf
+if [ -f "$ASIC_CONF" ]; then
+    source $ASIC_CONF
+fi
+
+# On Multi NPU platforms we need to start  the rsyslog server on the docker0 ip address
+# for the syslogs from the containers in the namespaces to work.
+# on Single NPU platforms we continue to use loopback adddres
+
+if [[ ($NUM_ASIC -gt 1) ]]; then
+    udp_server_ip=$(ip -o -4 addr list docker0 | awk '{print $4}' | cut -d/ -f1)
+else
+    udp_server_ip=$(ip -o -4 addr list lo scope host | awk '{print $4}' | cut -d/ -f1)
+fi
+
+sonic-cfggen -d -t /usr/share/sonic/templates/rsyslog.conf.j2 -a "{\"udp_server_ip\": \"$udp_server_ip\"}"  >/etc/rsyslog.conf
+
 systemctl restart rsyslog

files/image_config/rsyslog/rsyslog-container.conf.j2

@@ -0,0 +1,76 @@
+#
+#  /etc/rsyslog.conf    Configuration file for rsyslog.
+#
+#                       For more information see
+#                       /usr/share/doc/rsyslog-doc/html/rsyslog_conf.html
+
+
+#################
+#### MODULES ####
+#################
+
+$ModLoad imuxsock # provides support for local system logging
+
+#
+# Set a rate limit on messages from the container
+#
+$SystemLogRateLimitInterval 300
+$SystemLogRateLimitBurst 20000
+
+#$ModLoad imklog  # provides kernel logging support
+#$ModLoad immark  # provides --MARK-- message capability
+
+# provides UDP syslog reception
+#$ModLoad imudp
+#$UDPServerRun 514
+
+# provides TCP syslog reception
+#$ModLoad imtcp
+#$InputTCPServerRun 514
+
+
+###########################
+#### GLOBAL DIRECTIVES ####
+###########################
+
+# Set remote syslog server
+template (name="ForwardFormatInContainer" type="string" string="<%PRI%>%TIMESTAMP:::date-rfc3339% %HOSTNAME% {{container_name}}#%syslogtag%%msg:::sp-if-no-1st-sp%%msg%")
+*.* action(type="omfwd" target="{{target_ip}}" port="514" protocol="udp" Template="ForwardFormatInContainer")
+
+#
+# Use traditional timestamp format.
+# To enable high precision timestamps, comment out the following line.
+#
+#$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
+
+# Define a custom template
+$template SONiCFileFormat,"%TIMESTAMP%.%timestamp:::date-subseconds% %HOSTNAME% %syslogseverity-text:::uppercase% {{container_name}}#%syslogtag%%msg:::sp-if-no-1st-sp%%msg:::drop-last-lf%\n"
+$ActionFileDefaultTemplate SONiCFileFormat
+
+#
+# Set the default permissions for all log files.
+#
+$FileOwner root
+$FileGroup adm
+$FileCreateMode 0640
+$DirCreateMode 0755
+$Umask 0022
+
+#
+# Where to place spool and state files
+#
+$WorkDirectory /var/spool/rsyslog
+
+#
+# Include all config files in /etc/rsyslog.d/
+#
+$IncludeConfig /etc/rsyslog.d/*.conf
+
+#
+# Suppress duplicate messages and report "message repeated n times"
+#
+$RepeatedMsgReduction on
+
+###############
+#### RULES ####
+###############

files/image_config/rsyslog/rsyslog.conf.j2

@@ -19,7 +19,7 @@ $ModLoad imklog   # provides kernel logging support
 
 # provides UDP syslog reception
 $ModLoad imudp
-$UDPServerAddress 127.0.0.1 # bind to localhost before udp server run
+$UDPServerAddress {{udp_server_ip}}  #bind to localhost before udp server run
 $UDPServerRun 514
 
 # provides TCP syslog reception