Set umask instead of creating a new user

Dockerfile

@@ -1,15 +1,8 @@
 FROM ruby:2.3
 RUN apt-get update -qq && apt-get install -y nodejs
 
-# We need the spring socket file to be readable by the local user on the host,
-# so we need to set up a user account with the same UID. Change this if your
-# UID is not 1000. Obviously there are ways to make this more flexible (build
-# args etc).
-RUN useradd --create-home --user-group --uid 1000 app
-
 RUN mkdir /app && chown -R app:app /app
 WORKDIR /app
-USER app
 
 ADD Gemfile /app/Gemfile
 ADD Gemfile.lock /app/Gemfile.lock

docker-compose.yml

@@ -12,7 +12,7 @@ services:
     build: .
     volumes:
       - .:/app
-    command: spring server
+    command: sh -c "umask a+rw; exec spring server"
 
     # This ensures that the pid namespace is shared between the host
     # and the container. It's not necessary to be able to run spring