♻️ Re-create the Dockerfile with cache layers in mind

Dockerfile

@@ -1,14 +1,22 @@
-FROM node:12-alpine
+FROM node:12.18-alpine3.12
 
 EXPOSE 8061
 
-COPY . /iframely
-
 WORKDIR /iframely
 
-ENV NODE_ENV=production
+# Create new non-root user
+RUN addgroup -S iframelygroup && adduser -S iframely -G iframelygroup
+
+# This will change the config to `config.<VALUE>.js` and the express server to change its behaviour.
+# You should overwrite this on the CLI with `-e NODE_ENV=production`.
+ENV NODE_ENV=local
+
+## Utilize docker layer cache
+COPY package.json yarn.lock /iframely/
+RUN yarn install --pure-lockfile --production
+
+COPY . /iframely
 
-RUN apk add --no-cache git && \
-    yarn install --frozen-lockfile --production
+USER iframely
 
 ENTRYPOINT [ "/iframely/docker/entrypoint.sh" ]