add userid variable

Add a variable for the userid and use 1000 as default.

Dockerfile

@@ -18,7 +18,8 @@ RUN chmod +x docker-entrypoint.sh
 RUN mkdir -p /home/srm/tmp
 #COPY Gemfile.lock /home/srm/tmp/Gemfile.lock
 
-RUN groupadd -r srm && useradd -r -g srm srm
+ARG USER_ID=1000
+RUN groupadd srm && useradd -D --uid $USER_ID -g srm srm
 RUN chown -R srm:srm /home/srm
 USER srm
 

docker-compose.yml

@@ -2,7 +2,10 @@ version: "3.7"
 services:
   web:
     user: srm
-    build: .
+    build:
+      context: .
+      args: 
+        - USER_ID=1000
     volumes:
       - .:/app
     ports: