[202311][dhcp_server] Add rsyslog support for dhcp_server (#19303)

dockers/docker-dhcp-server/Dockerfile.j2

@@ -3,7 +3,6 @@ FROM docker-config-engine-bullseye-{{DOCKER_USERNAME}}:{{DOCKER_USERTAG}}
 
 ARG docker_container_name
 ARG image_version
-RUN [ -f /etc/rsyslog.conf ] && sed -ri "s/%syslogtag%/$docker_container_name#%syslogtag%/;" /etc/rsyslog.conf
 
 ## Make apt-get non-interactive
 ENV DEBIAN_FRONTEND=noninteractive
@@ -50,8 +49,6 @@ RUN cd /usr/local/sbin && rm -f kea-admin kea-ctrl-agent kea-dhcp-ddns kea-dhcp6
 # Remove hook lib we don't need
 RUN cd /usr/local/lib/kea/hooks && rm -f libdhcp_bootp.so libdhcp_flex_option.so libdhcp_stat_cmds.so
 RUN pip3 install psutil
-# TODO issue on remote rsyslog server in non-host container
-RUN rm -f /etc/supervisor/conf.d/containercfgd.conf
 
 {% if docker_dhcp_server_debs.strip() -%}
 # Copy locally-built Debian package dependencies
@@ -86,11 +83,10 @@ RUN apt-get clean -y        && \
 COPY ["docker_init.sh", "start.sh", "/usr/bin/"]
 COPY ["supervisord.conf", "/etc/supervisor/conf.d/"]
 COPY ["files/supervisor-proc-exit-listener", "/usr/bin"]
-COPY ["rsyslog/rsyslog.conf.j2", "kea-dhcp4.conf.j2", "/usr/share/sonic/templates/"]
+COPY ["kea-dhcp4.conf.j2", "/usr/share/sonic/templates/"]
 COPY ["critical_processes", "/etc/supervisor/"]
 COPY ["lease_update.sh", "/etc/kea/"]
 COPY ["kea-dhcp4-init.conf", "/etc/kea/kea-dhcp4.conf"]
 COPY ["cli", "/cli/"]
-COPY ["rsyslog/default.conf", "/etc/rsyslog.d"]
 
 ENTRYPOINT ["/usr/bin/docker_init.sh"]

dockers/docker-dhcp-server/docker_init.sh

@@ -7,11 +7,6 @@ mkdir -p /etc/supervisor/conf.d/
 mkdir -p /etc/kea/
 udp_server_ip=$(ip -j -4 addr list lo scope host | jq -r -M '.[0].addr_info[0].local')
 hostname=$(hostname)
-# Generate the following files from templates:
-# port-to-alias name map
-sonic-cfggen -d -t /usr/share/sonic/templates/rsyslog.conf.j2 \
-    -a "{\"udp_server_ip\": \"$udp_server_ip\", \"hostname\": \"$hostname\"}" \
-    > /etc/rsyslog.conf
 
 # Make the script that waits for all interfaces to come up executable
 chmod +x /etc/kea/lease_update.sh /usr/bin/start.sh

files/build_templates/docker_image_ctl.j2

@@ -331,7 +331,11 @@ start() {
     fi
 
     # Default rsyslog target IP for single ASIC platform
+{%- if docker_container_name == "dhcp_server" %}
+    SYSLOG_TARGET_IP=$(docker network inspect bridge --format={{ "'{{(index .IPAM.Config 0).Gateway}}'" }})
+{%- else %}
     SYSLOG_TARGET_IP=127.0.0.1
+{%- endif %}
     if [[ ($NUM_ASIC -gt 1) ]]; then
         SYSLOG_TARGET_IP=$(docker network inspect bridge --format={{ "'{{(index .IPAM.Config 0).Gateway}}'" }})
     fi

files/image_config/rsyslog/rsyslog-config.sh

@@ -17,10 +17,16 @@ if [[ ($NUM_ASIC -gt 1) ]]; then
 else
     udp_server_ip=$(ip -j -4 addr list lo scope host | jq -r -M '.[0].addr_info[0].local')
 fi
+
+contain_dhcp_server=$(sonic-db-cli CONFIG_DB keys "FEATURE|dhcp_server")
+if [ $contain_dhcp_server ]; then
+    docker0_ip=$(ip -o -4 addr list docker0 | awk '{print $4}' | cut -d/ -f1)
+fi
+
 hostname=$(hostname)
 
 sonic-cfggen -d -t /usr/share/sonic/templates/rsyslog.conf.j2 \
-    -a "{\"udp_server_ip\": \"$udp_server_ip\", \"hostname\": \"$hostname\"}" \
+    -a "{\"udp_server_ip\": \"$udp_server_ip\", \"hostname\": \"$hostname\", \"docker0_ip\": \"$docker0_ip\"}" \
     > /etc/rsyslog.conf
 
 systemctl restart rsyslog

files/image_config/rsyslog/rsyslog.conf.j2

@@ -33,6 +33,10 @@ $ModLoad imklog   # provides kernel logging support
 $ModLoad imudp
 $UDPServerAddress {{udp_server_ip}}  #bind to localhost before udp server run
 $UDPServerRun 514
+{% if docker0_ip and docker0_ip != "" %}
+$UDPServerAddress {{docker0_ip}}
+$UDPServerRun 514
+{% endif%}
 
 # provides TCP syslog reception
 #$ModLoad imtcp