creating slim image

.docker/dockerfiles/develop/Dockerfile

-FROM node:0.10-slim
+FROM node:0.10
 
 # IMPORTANT - FOR TESTING ONLY - DO NOT USE THIS FOR DEVELOPMENT OR PRODUCTION!
 MAINTAINER buildmaster@rocket.chat

.docker/dockerfiles/slim/Dockerfile

+FROM debian:jessie
+
+# IMPORTANT - FOR TESTING ONLY - DO NOT USE THIS FOR DEVELOPMENT OR PRODUCTION!
+MAINTAINER buildmaster@rocket.chat
+
+# gpg: key 4FD08014: public key "Rocket.Chat Buildmaster <buildmaster@rocket.chat>" imported
+RUN gpg --keyserver ha.pool.sks-keyservers.net --recv-keys 0E163286C20D07B9787EBE9FD7F9D0414FD08104
+
+# gpg keys listed at https://github.com/nodejs/node
+RUN set -ex \
+ && for key in \
+      9554F04D7259F04124DE6B476D5A82AC7E37093B \
+      94AE36675C464D64BAFA68DD7434390BDBE9B9C5 \
+      0034A06D9D9B0064CE8ADF6BF1747F4AD2306D93 \
+      FD3A5288F042B6850C66B31F09FE44734EB7990E \
+      71DCFD284A79C3B38668286BC97EC7A07EDE3FC1 \
+      DD8F2338BAE7501E3DD5AC78C273792F7D83545D \
+      B9AE9905FFD7803F25714661B63B535A4C206CA9 \
+      C4F0DFFF4E8C1A8236409D08E73BC641CC11F4C8 \
+    ; do \
+    gpg --keyserver ha.pool.sks-keyservers.net --recv-keys "$key"; \
+    done
+
+ENV NODE_VERSION 0.10.42
+ENV NPM_VERSION 2.14.1
+ENV RC_VERSION develop
+
+VOLUME /app/uploads
+
+RUN buildDeps='curl ca-certificates imagemagick' \
+ && set -x \
+ && apt-get update && apt-get install -y $buildDeps --no-install-recommends \
+
+ && curl -SLO "https://nodejs.org/dist/v$NODE_VERSION/node-v$NODE_VERSION-linux-x64.tar.gz" \
+ && curl -SLO "https://nodejs.org/dist/v$NODE_VERSION/SHASUMS256.txt.asc" \
+ && gpg --verify SHASUMS256.txt.asc \
+ && grep " node-v$NODE_VERSION-linux-x64.tar.gz\$" SHASUMS256.txt.asc | sha256sum -c - \
+ && tar -xzf "node-v$NODE_VERSION-linux-x64.tar.gz" -C /usr/local --strip-components=1 \
+ && rm "node-v$NODE_VERSION-linux-x64.tar.gz" SHASUMS256.txt.asc \
+ && npm install -g npm@"$NPM_VERSION" \
+
+ && groupadd -r rocketchat \
+ && useradd -r -g rocketchat rocketchat
+ && curl -SLf "https://rocket.chat/releases/${RC_VERSION}/download" -o rocket.chat.tgz \
+ && curl -SLf "https://rocket.chat/releases/${RC_VERSION}/asc" -o rocket.chat.tgz.asc \
+ && gpg --verify rocket.chat.tgz.asc \
+ && tar -zxf rocket.chat.tgz -C /app \
+ && rm rocket.chat.tgz rocket.chat.tgz.asc \
+ && cd /app/bundle/programs/server \
+ && npm install
+
+ && rm -rf /var/lib/apt/lists/* \
+ && npm cache clear
+# && apt-get purge -y --auto-remove $buildDeps \
+
+USER rocketchat
+
+WORKDIR /app/bundle
+
+# needs a mongoinstance - defaults to container linking with alias 'mongo'
+ENV MONGO_URL=mongodb://mongo:27017/rocketchat \
+    PORT=3000 \
+    ROOT_URL=http://localhost:3000 \
+    Accounts_AvatarStorePath=/app/uploads
+
+EXPOSE 3000
+
+CMD ["node", "main.js"]