added user and group id mapping

Dockerfile

@@ -7,10 +7,8 @@ LABEL Description="This image is used to learn building dockerfiles" \
 
 # environment variables
 ENV JEKYLL_SITE=default
-
-# copy stuff into the image
-COPY jekyll.sh jekyll.sh
-RUN chmod +x jekyll.sh
+ENV USER_ID=1000
+ENV GROUP_ID=1000
 
 # expose port for `jekyll serve`
 EXPOSE 4000
@@ -18,9 +16,17 @@ EXPOSE 4000
 # volume definitions
 VOLUME ["/mnt"]
 
-# prepare the baseimage
+# prepare the baseimage and create 
 RUN apt-get update && apt-get install -y ruby ruby-dev gcc g++ make libssl-dev libreadline-dev && \
-    gem update && gem install jekyll bundler
+    gem update && gem install jekyll bundler && \
+    groupadd -g $GROUP_ID jekyll-dev && \
+    useradd -u $USER_ID -g $GROUP_ID -M -d /mnt -s /bin/false jekyll-dev
+
+USER jekyll-dev
+
+RUN cd /mnt && \
+    if [ ! -d "/mnt/$JEKYLL_SITE" ]; then jekyll new $JEKYLL_SITE; fi && \
+    cd $JEKYLL_SITE && bundle install
 
 # run command
-CMD ./jekyll.sh
+CMD bundle exec jekyll serve --host=0.0.0.0 --incremental

docker-compose.yml

@@ -10,4 +10,6 @@ services:
     ports: 
       - 127.0.0.1:4000:4000
     environment:
-      - JEKYLL_SITE=docs
+      - JEKYLL_SITE=docs
+      - USER_ID=1000
+      - GROUP_ID=1000

jekyll.sh

@@ -1,11 +0,0 @@
-#!/bin/bash
-
-# create new or serve existing jekyll page (/mnt/$JEKYLL_SITE)
-
-cd /mnt
-if [ ! -d "/mnt/$JEKYLL_SITE" ]; then
-  jekyll new $JEKYLL_SITE
-fi
-cd $JEKYLL_SITE
-bundle install
-bundle exec jekyll serve --host=0.0.0.0 --incremental