fix: non-root user in Dockerfile (#496)

* fix: non-root user in Dockerfile

* fix: add user

* fix: change commands to work for alpine

Dockerfile

@@ -10,14 +10,18 @@ WORKDIR /opt/payid
 
 COPY . .
 
+# create a group and user
+RUN addgroup -S appgroup && adduser -S appuser -G appgroup
+
 # postgresql-client is needed if/when we run "wait-for-postgres.sh" (in ./scripts) to make sure Postgres is ready to execute SQL scripts.
 RUN apk --no-cache add postgresql-client~=12 &&\
     npm cache clean --force &&\
     npm install &&\
-    npm run build &&\
-    ls -al /opt/payid/build/ &&\
-    ls -al /opt/payid/build/src
+    npm run build 
 
 EXPOSE 8080 8081
 
-CMD ["node", "/opt/payid/build/src/index.js"]
+# run all future commands as this user
+USER appuser 
+
+CMD ["node", "/opt/payid/build/src/index.js"]