Unbound mysql port to host; made project name an env variable

.env.example

@@ -1,3 +1,11 @@
+#Project Name
+#Critical when running multiple Zeppelin instances on the same computer.
+#Must be unique across all project names/folders.
+#Use a meaningful name so that you remember what it's for 1 year down the line.
+#If runnning only one Zeppelin instance, or this is your first one, you may leave this blank.
+#Defaults to "zeppelin_prod" if left blank.
+PROJECT_NAME=
+
 # 32 character encryption key
 KEY=
 
@@ -60,7 +68,9 @@ DOCKER_PROD_DOMAIN=
 DOCKER_PROD_WEB_PORT=443
 # The MySQL database running in the container is exposed to the host on this port,
 # allowing access with database tools such as DBeaver
-DOCKER_PROD_MYSQL_PORT=3001
+# Defaults to 3306 if left blank.
+# If you need to access your database from host/outside, follow the instructions in docker-compose.production.yml as well.
+DOCKER_PROD_MYSQL_PORT=
 # Password for the Zeppelin database user
 DOCKER_PROD_MYSQL_PASSWORD=
 # Password for the MySQL root user
@@ -75,4 +85,4 @@ DOCKER_PROD_MYSQL_ROOT_PASSWORD=
 
 #nginx-proxy related
 LETSENCRYPT_EMAIL=
-DEBUG=
+DEBUG=

docker-compose.production.yml

@@ -1,5 +1,5 @@
 version: '3'
-name: zeppelin-prod
+name: ${PROJECT_NAME:-zeppelin-prod}
 services:
   nginx:
     build:
@@ -30,8 +30,11 @@ services:
       MYSQL_DATABASE: zeppelin
       MYSQL_USER: zeppelin
       MYSQL_PASSWORD: ${DOCKER_PROD_MYSQL_PASSWORD?:Missing DOCKER_PROD_MYSQL_PASSWORD}
-    ports:
+    expose:
-      - ${DOCKER_PROD_MYSQL_PORT:?Missing DOCKER_PROD_MYSQL_PORT}:3306
+      - 3306
+    #Comment the expose section above AND uncomment the ports section below if the database needs to be accessible from host computer or from outside.
+    #ports:
+    #  - ${DOCKER_PROD_MYSQL_PORT:-3306}:3306
     volumes:
       - ./docker/production/data/mysql:/var/lib/mysql
     command: --authentication-policy=mysql_native_password