Merge pull request #13 from bryanlatten/feature-alpine-3.5

Dockerfile: updated Alpine to 3.5

Dockerfile-alpine

@@ -1,4 +1,4 @@
-FROM alpine:3.4
+FROM alpine:3.5
 LABEL Maintainer="Bryan Latten <[email protected]>"
 
 # Use in multi-phase builds, when an init process requests for the container to gracefully exit, so that it may be committed
@@ -13,7 +13,12 @@ ENV SIGNAL_BUILD_STOP=99 \
 # Ensure scripts are available for use in next command
 COPY ./container/root/scripts/* /scripts/
 
-RUN echo '@edge http://dl-cdn.alpinelinux.org/alpine/edge/testing' >> /etc/apk/repositories && \
+# - Symlink variant-specific scripts to default location
+# - Add additional repositories to pull packages from
+# - Add S6 for zombie reaping, boot-time coordination, signal transformation/distribution: @see https://github.com/just-containers/s6-overlay#known-issues-and-workarounds
+# - Add goss for local, serverspec-like testing
+RUN ln -s /scripts/clean_alpine.sh /clean.sh && \
+    echo '@edge http://dl-cdn.alpinelinux.org/alpine/edge/testing' >> /etc/apk/repositories && \
     apk update && \
     apk add --no-cache \
         sed \
@@ -29,7 +34,7 @@ RUN echo '@edge http://dl-cdn.alpinelinux.org/alpine/edge/testing' >> /etc/apk/r
     curl -L https://github.com/aelsabbahy/goss/releases/download/${GOSS_VERSION}/goss-linux-amd64 -o /usr/local/bin/goss && \
     chmod +x /usr/local/bin/goss && \
     apk del curl && \
-    rm -rf /var/cache/apk/*
+    /bin/bash -e /clean.sh
 
 # Overlay the root filesystem from this repo
 COPY ./container/root /

README.md

@@ -35,11 +35,13 @@ On Ubuntu and CentOS-based variants, run:
 
 This file is actually a symlink to the variant-specific script contained in the `/scripts` folder
 
+NOTE: for Alpine variant, which is security-conscious, but does not have a mechanism to isolate security-specific updates, use `apk update && apk upgrade` as a generic alternative.
+
 ### Packaging
 
 A convenience script is provided for post-package installation cleanup
 
-On Ubuntu and CentOS-based variants, run: 
+On all variants, run: 
 ```/bin/bash -e /clean.sh```
 
 This file, like security_updates (above) is actually a symlink to the variant-specific script contained in the `/scripts` folder

container/root/scripts/clean_alpine.sh

@@ -0,0 +1,10 @@
+#!/bin/bash -e
+
+# --- Alpine variant only, for other variants, see /scripts folder
+
+#-------------------------------------------------------------------
+# Performs cleanup, ensure unnecessary packages and package lists
+# are safely removed, without triggering Docker AUFS permission bug
+#-------------------------------------------------------------------
+
+rm -rf /var/cache/apk/*