Reduce image size with some tricks

Author: fabiang

Dockerfile

@@ -1,27 +1,22 @@
 FROM ubuntu:16.04
 
-MAINTAINER Fabian Grutschus "f.grutschus@lubyte"
+MAINTAINER Fabian Grutschus "docker@lubyte.de"
 
-RUN apt-get update
-
-RUN apt-get install -y curl apt-transport-https locales
-
-ENV ACCEPT_EULA=Y
-
-RUN locale-gen "en_US.UTF-8"
+ENV MSSQLTOOLS_VERSION=17.1.0.1-1
+ENV PATH /opt/mssql-tools/bin:$PATH
 
-RUN curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - \
+RUN apt-get update \
+    && apt-get install -y curl apt-transport-https locales \
+    && locale-gen "en_US.UTF-8" \
+    && curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - \
     && curl https://packages.microsoft.com/config/ubuntu/16.04/prod.list | tee /etc/apt/sources.list.d/msprod.list \
     && apt-get update \
-    && apt-get install -y mssql-tools unixodbc-dev
-
-ENV PATH /opt/mssql-tools/bin:$PATH
-
-RUN apt-get remove -y curl apt-transport-https \
-    && apt-get autoremove -y \
-    && apt-get clean \
-    && apt-get autoclean
+    && ACCEPT_EULA=Y apt-get install -y mssql-tools=$MSSQLTOOLS_VERSION unixodbc-dev \
+    && apt-get remove -y curl apt-transport-https \
+    && rm -f /etc/apt/sources.list.d/msprod.list \
+    && rm -rf /var/lib/apt/lists/*
 
-ENV LANG="en_US.UTC-8"
+## should be set after locale was generate, overwise triggers warnings
+ENV LANG="en_US.UTF-8" LANGUAGE="en_US.UTF-8" LC_ALL="en_US.UTF-8"
 
 ENTRYPOINT ["sqlcmd"]