[orchagent] Use mac address from config_db instead of from eth0 (sonic-net#4166)

* Use mac address from config_db instead of eth0

Author: prsunny

dockers/docker-orchagent/orchagent.sh

@@ -4,7 +4,11 @@
 # vendor specific code.
 export platform=`sonic-cfggen -y /etc/sonic/sonic_version.yml -v asic_type`
 
-MAC_ADDRESS=`ip link show eth0 | grep ether | awk '{print $2}'`
+MAC_ADDRESS=$(sonic-cfggen -d -v 'DEVICE_METADATA.localhost.mac')
+if [ "$MAC_ADDRESS" == "None" ] || [ -z "$MAC_ADDRESS" ]; then
+    MAC_ADDRESS=$(ip link show eth0 | grep ether | awk '{print $2}')
+    logger "Mac address not found in Device Metadata, Falling back to eth0"
+fi
 
 # Create a folder for SwSS record files
 mkdir -p /var/log/swss

platform/p4/docker-sonic-p4/orchagent.sh

@@ -1,6 +1,10 @@
 #!/usr/bin/env bash
 
-MAC_ADDRESS=`ip link show eth0 | grep ether | awk '{print $2}'`
+MAC_ADDRESS=$(sonic-cfggen -d -v 'DEVICE_METADATA.localhost.mac')
+if [ "$MAC_ADDRESS" == "None" ] || [ -z "$MAC_ADDRESS" ]; then
+    MAC_ADDRESS=$(ip link show eth0 | grep ether | awk '{print $2}')
+    logger "Mac address not found in Device Metadata, Falling back to eth0"
+fi
 
 # Create a folder for SsWW record files
 mkdir -p /var/log/swss

platform/vs/docker-sonic-vs/orchagent.sh

@@ -6,7 +6,11 @@ else
     export platform=$fake_platform
 fi
 
-MAC_ADDRESS=`ip link show eth0 | grep ether | awk '{print $2}'`
+MAC_ADDRESS=$(sonic-cfggen -d -v 'DEVICE_METADATA.localhost.mac')
+if [ "$MAC_ADDRESS" == "None" ] || [ -z "$MAC_ADDRESS" ]; then
+    MAC_ADDRESS=$(ip link show eth0 | grep ether | awk '{print $2}')
+    logger "Mac address not found in Device Metadata, Falling back to eth0"
+fi
 
 # Create a folder for SwSS record files
 mkdir -p /var/log/swss