feat: accept third octet as an environment

build.sh

@@ -45,9 +45,11 @@ fi
 
 source .env
 export DOCKER_NETWORK_NAME="snapshotter-lite-v2-${SLOT_ID}"
-# remove any existing network with this name
-SUBNET_THIRD_OCTET=$((SLOT_ID % 256))
-# Use 172.18 as the first two octets
+# Use 172.18.0.0/16 as the base, which is within Docker's default pool
+if [ -z "$SUBNET_THIRD_OCTET" ]; then
+    SUBNET_THIRD_OCTET=$((SLOT_ID % 256))
+    echo "SUBNET_THIRD_OCTET not found in .env, setting to default value ${SUBNET_THIRD_OCTET}"
+fi
 export DOCKER_NETWORK_SUBNET="172.18.${SUBNET_THIRD_OCTET}.0/24"
 
 echo "Selected DOCKER_NETWORK_NAME: ${DOCKER_NETWORK_NAME}"