change znc to alpine

Signed-off-by: Jess Frazelle <acidburn@google.com>

znc/Dockerfile

@@ -6,44 +6,51 @@
 #	-v /volumes/znc:/home/user/.znc \
 #	jess/znc
 #
-FROM debian:stretch
+FROM alpine:latest
 MAINTAINER Jessie Frazelle <jess@linux.com>
 
-RUN apt-get update && apt-get install -y \
+RUN apk add --no-cache \
 	ca-certificates \
-	curl \
-	libdatetime-perl \
-	libglib2.0-0 \
-	libwww-perl \
+	glib \
 	perl \
-	&& rm -rf /var/lib/apt/lists/*
+	perl-datetime \
+	perl-libwww
 
 ENV HOME /home/user
-RUN useradd --create-home --home-dir $HOME user \
+RUN adduser -u 1001 -D user \
 	&& chown -R user:user $HOME
 
 ENV LANG C.UTF-8
 
 ENV ZNC_VERSION 1.6.4
 
-RUN buildDeps=' \
-		build-essential \
-		libssl-dev \
-		libperl-dev \
-	' \
-	&& set -x \
-	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends \
-	&& rm -rf /var/lib/apt/lists/* \
+RUN set -x \
+	&& apk add --no-cache --virtual .build-deps \
+		build-base \
+		curl \
+		libressl-dev \
+		perl-dev \
+		tar \
 	&& curl -sSL "http://znc.in/releases/znc-${ZNC_VERSION}.tar.gz" -o /tmp/znc.tar.gz \
 	&& mkdir -p /usr/src/znc \
 	&& tar -xzf /tmp/znc.tar.gz -C /usr/src/znc --strip-components 1 \
 	&& rm /tmp/znc.tar.gz* \
-	&& cd /usr/src/znc \
+	&& ( \
+		cd /usr/src/znc \
 		&& ./configure \
 		&& make -j8 \
 		&& make install \
+	) \
 	&& rm -rf /usr/src/znc \
-	&& apt-get purge -y --auto-remove $buildDeps
+	&& runDeps="$( \
+		scanelf --needed --nobanner --recursive /usr \
+			| awk '{ gsub(/,/, "\nso:", $2); print "so:" $2 }' \
+			| sort -u \
+			| xargs -r apk info --installed \
+			| sort -u \
+	)" \
+	&& apk add --no-cache --virtual .irssi-rundeps $runDeps \
+	&& apk del .build-deps
 
 WORKDIR $HOME
 USER user