update dockerfile to generate rabbitmq config settings when necessary

docker/main.sh

@@ -25,6 +25,32 @@ if [ -z "$ZT_DB_PASSWORD" ]; then
     exit 1
 fi
 
+RMQ=""
+if [ "$ZT_USE_RABBITMQ" == "true" ]; then
+    if [ -z "$RABBITMQ_HOST" ]; then
+        echo '*** FAILED: RABBITMQ_HOST environment variable not defined'
+        exit 1
+    fi
+    if [ -z "$RABBITMQ_PORT" ]; then
+        echo '*** FAILED: RABBITMQ_PORT environment variable not defined'
+        exit 1
+    fi
+    if [ -z "$RABBITMQ_USERNAME" ]; then
+        echo '*** FAILED: RABBITMQ_USERNAME environment variable not defined'
+        exit 1
+    fi
+    if [ -z "$RABBITMQ_PASSWORD" ]; then
+        echo '*** FAILED: RABBITMQ_PASSWORD environment variable not defined'
+        exit 1
+    fi
+    RMQ=", \"rabbitmq\": {
+        \"host\": \"${RABBITMQ_HOST}\",
+        \"port\": ${RABBITMQ_PORT},
+        \"username\": \"${RABBITMQ_USERNAME}\",
+        \"password\": \"${RABBITMQ_PASSWORD}\"
+    }"
+fi
+
 mkdir -p /var/lib/zerotier-one
 
 pushd /var/lib/zerotier-one
@@ -43,6 +69,7 @@ echo "{
             \"nat64\"
         ],
         \"controllerDbPath\": \"postgres:host=${ZT_DB_HOST} port=${ZT_DB_PORT} dbname=${ZT_DB_NAME} user=${ZT_DB_USER} password=${ZT_DB_PASSWORD} sslmode=prefer sslcert=${DB_CLIENT_CERT} sslkey=${DB_CLIENT_KEY} sslrootcert=${DB_SERVER_CA}\"
+        ${RMQ}
     }
 }    
 " > /var/lib/zerotier-one/local.conf