Support for connecting to DB in namespace via TCP port in multi-asic …

…platform. (sonic-net#4779)

* Support for connecting to DB in namespace via IP:port ( using docker bridge network ) for applications in multi-asic platform.

* Added the default IP as 127.0.0.1 if the IPaddress derivation from interface fails.
Moved the localhost loopback IP binding logic into the supervisor.j2 file.

dockers/docker-database/database_config.json.j2

@@ -1,7 +1,7 @@
 {
     "INSTANCES": {
         "redis":{
-            "hostname" : "127.0.0.1",
+            "hostname" : "{{HOST_IP}}",
             "port" : 6379,
             "unix_socket_path" : "/var/run/redis{{NAMESPACE_ID}}/redis.sock",
             "persistence_for_warm_boot" : "yes"

dockers/docker-database/docker-database-init.sh

@@ -1,12 +1,29 @@
 #!/usr/bin/env bash
 
+# For linux host namespace, in both single and multi ASIC platform use the loopback interface
+# For other namespaces, use eth0 interface which is connected to the docker0 bridge in the host.
+if [[ $NAMESPACE_ID == "" ]]
+then
+    INTFC=lo
+else
+    INTFC=eth0
+fi
+
+# Get the ip address of the interface
+# if the ip address was not retrieved correctly, put localhost(127.0.0.1) as the default.
+host_ip=$(ip -4 -o addr show $INTFC | awk '{print $4}' | cut -d'/' -f1 | head -1)
+if [[ $host_ip == "" ]]
+then
+    host_ip=127.0.0.1
+fi
+
 REDIS_DIR=/var/run/redis$NAMESPACE_ID
 mkdir -p $REDIS_DIR/sonic-db
 
 if [ -f /etc/sonic/database_config$NAMESPACE_ID.json ]; then
     cp /etc/sonic/database_config$NAMESPACE_ID.json $REDIS_DIR/sonic-db/database_config.json
 else
-    j2 /usr/share/sonic/templates/database_config.json.j2 > $REDIS_DIR/sonic-db/database_config.json
+    HOST_IP=$host_ip j2 /usr/share/sonic/templates/database_config.json.j2 > $REDIS_DIR/sonic-db/database_config.json
 fi
 
 mkdir -p /etc/supervisor/conf.d/

dockers/docker-database/supervisord.conf.j2

@@ -20,7 +20,12 @@ stderr_logfile=syslog
 {% if INSTANCES %}
 {%     for redis_inst, redis_items in INSTANCES.iteritems() %}
 [program: {{ redis_inst }}]
-command=/bin/bash -c "{ [[ -s /var/lib/{{ redis_inst }}/dump.rdb ]] || rm -f /var/lib/{{ redis_inst }}/dump.rdb; } && mkdir -p /var/lib/{{ redis_inst }} && exec /usr/bin/redis-server /etc/redis/redis.conf --port {{ redis_items['port'] }} --unixsocket {{ redis_items['unix_socket_path'] }} --pidfile /var/run/redis/{{ redis_inst }}.pid --dir /var/lib/{{ redis_inst }}"
+{% if redis_items['hostname'] != '127.0.0.1' %}
+{%- set LOOPBACK_IP = '127.0.0.1' -%}
+{%- else -%}
+{%- set LOOPBACK_IP = '' -%}
+{%- endif -%}
+command=/bin/bash -c "{ [[ -s /var/lib/{{ redis_inst }}/dump.rdb ]] || rm -f /var/lib/{{ redis_inst }}/dump.rdb; } && mkdir -p /var/lib/{{ redis_inst }} && exec /usr/bin/redis-server /etc/redis/redis.conf --bind {{ LOOPBACK_IP }} {{ redis_items['hostname'] }} --port {{ redis_items['port'] }} --unixsocket {{ redis_items['unix_socket_path'] }} --pidfile /var/run/redis/{{ redis_inst }}.pid --dir /var/lib/{{ redis_inst }}"
 priority=2
 autostart=true
 autorestart=false