Dockerfiles optimized

Dockerfile

@@ -1,19 +1,20 @@
 FROM debian:stretch-slim
 
 ARG DEBIAN_FRONTEND=noninteractive
-
 RUN apt-get update \
-    && apt-get install -y --no-install-recommends apt-utils \
     && apt-get install -y --no-install-recommends \
         curl \
+        ca-certificates \
         gnupg2 \
     && curl -sL https://deb.nodesource.com/setup_8.x | bash - \
-    && apt-get install -y \
+    && apt-get install -y --no-install-recommends \
         nodejs \
+    && apt-get purge -y --auto-remove \
+        curl \
+        gnupg2 \
     && rm -rf /var/lib/apt/lists/* \
     && npm -g install pm2
 
-
 WORKDIR /salix
 COPY package.json package-lock.json ./
 COPY loopback/package.json loopback/

services/nginx/Dockerfile

@@ -2,12 +2,10 @@ FROM debian:stretch-slim
 EXPOSE 80
 
 ARG DEBIAN_FRONTEND=noninteractive
-
 RUN apt-get update \
     && apt-get install -y --no-install-recommends nginx \
-    && rm -rf /var/lib/apt/lists/* 
-
-RUN ln -sf /dev/stdout /var/log/nginx/access.log \
+    && rm -rf /var/lib/apt/lists/* \
+    && ln -sf /dev/stdout /var/log/nginx/access.log \
     && ln -sf /dev/stderr /var/log/nginx/error.log
 
 WORKDIR /etc/nginx