Replace "stretch" with "buster" for Ruby 2.7-rc given the imminent Debian release

(and ditch Alpine 3.9 in 2.7-rc)

.travis.yml

@@ -2,10 +2,9 @@ language: bash
 services: docker
 
 env:
-  - VERSION=2.7-rc VARIANT=stretch
-  - VERSION=2.7-rc VARIANT=stretch/slim
+  - VERSION=2.7-rc VARIANT=buster
+  - VERSION=2.7-rc VARIANT=buster/slim
   - VERSION=2.7-rc VARIANT=alpine3.10
-  - VERSION=2.7-rc VARIANT=alpine3.9
   - VERSION=2.6 VARIANT=stretch
   - VERSION=2.6 VARIANT=stretch/slim
   - VERSION=2.6 VARIANT=alpine3.10

2.7-rc/alpine3.9/Dockerfile

@@ -1,118 +0,0 @@
-FROM alpine:3.9
-
-RUN apk add --no-cache \
-		gmp-dev
-
-# skip installing gem documentation
-RUN mkdir -p /usr/local/etc \
-	&& { \
-		echo 'install: --no-document'; \
-		echo 'update: --no-document'; \
-	} >> /usr/local/etc/gemrc
-
-ENV RUBY_MAJOR 2.7-rc
-ENV RUBY_VERSION 2.7.0-preview1
-ENV RUBY_DOWNLOAD_SHA256 8c546df3345398b3edc9d0ab097846f033783d33762889fd0f3dc8bb465c3354
-
-# some of ruby's build scripts are written in ruby
-#   we purge system ruby later to make sure our final image uses what we just built
-# readline-dev vs libedit-dev: https://bugs.ruby-lang.org/issues/11869 and https://github.com/docker-library/ruby/issues/75
-RUN set -ex \
-	\
-	&& apk add --no-cache --virtual .ruby-builddeps \
-		autoconf \
-		bison \
-		bzip2 \
-		bzip2-dev \
-		ca-certificates \
-		coreutils \
-		dpkg-dev dpkg \
-		gcc \
-		gdbm-dev \
-		glib-dev \
-		libc-dev \
-		libffi-dev \
-		libxml2-dev \
-		libxslt-dev \
-		linux-headers \
-		make \
-		ncurses-dev \
-		openssl \
-		openssl-dev \
-		procps \
-		readline-dev \
-		ruby \
-		tar \
-		xz \
-		yaml-dev \
-		zlib-dev \
-	\
-	&& wget -O ruby.tar.xz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR%-rc}/ruby-$RUBY_VERSION.tar.xz" \
-	&& echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.xz" | sha256sum -c - \
-	\
-	&& mkdir -p /usr/src/ruby \
-	&& tar -xJf ruby.tar.xz -C /usr/src/ruby --strip-components=1 \
-	&& rm ruby.tar.xz \
-	\
-	&& cd /usr/src/ruby \
-	\
-# https://github.com/docker-library/ruby/issues/196
-# https://bugs.ruby-lang.org/issues/14387#note-13 (patch source)
-# https://bugs.ruby-lang.org/issues/14387#note-16 ("Therefore ncopa's patch looks good for me in general." -- only breaks glibc which doesn't matter here)
-	&& wget -O 'thread-stack-fix.patch' 'https://bugs.ruby-lang.org/attachments/download/7081/0001-thread_pthread.c-make-get_main_stack-portable-on-lin.patch' \
-	&& echo '3ab628a51d92fdf0d2b5835e93564857aea73e0c1de00313864a94a6255cb645 *thread-stack-fix.patch' | sha256sum -c - \
-	&& patch -p1 -i thread-stack-fix.patch \
-	&& rm thread-stack-fix.patch \
-	\
-# hack in "ENABLE_PATH_CHECK" disabling to suppress:
-#   warning: Insecure world writable dir
-	&& { \
-		echo '#define ENABLE_PATH_CHECK 0'; \
-		echo; \
-		cat file.c; \
-	} > file.c.new \
-	&& mv file.c.new file.c \
-	\
-	&& autoconf \
-	&& gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
-# the configure script does not detect isnan/isinf as macros
-	&& export ac_cv_func_isnan=yes ac_cv_func_isinf=yes \
-	&& ./configure \
-		--build="$gnuArch" \
-		--disable-install-doc \
-		--enable-shared \
-	&& make -j "$(nproc)" \
-	&& make install \
-	\
-	&& runDeps="$( \
-		scanelf --needed --nobanner --format '%n#p' --recursive /usr/local \
-			| tr ',' '\n' \
-			| sort -u \
-			| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
-	)" \
-	&& apk add --no-network --virtual .ruby-rundeps $runDeps \
-		bzip2 \
-		ca-certificates \
-		libffi-dev \
-		procps \
-		yaml-dev \
-		zlib-dev \
-	&& apk del --no-network .ruby-builddeps \
-	&& cd / \
-	&& rm -r /usr/src/ruby \
-# rough smoke test
-	&& ruby --version && gem --version && bundle --version
-
-# install things globally, for great justice
-# and don't create ".bundle" in all our apps
-ENV GEM_HOME /usr/local/bundle
-ENV BUNDLE_PATH="$GEM_HOME" \
-	BUNDLE_SILENCE_ROOT_WARNING=1 \
-	BUNDLE_APP_CONFIG="$GEM_HOME"
-# path recommendation: https://github.com/bundler/bundler/pull/6469#issuecomment-383235438
-ENV PATH $GEM_HOME/bin:$BUNDLE_PATH/gems/bin:$PATH
-# adjust permissions of a few directories for running "gem install" as an arbitrary user
-RUN mkdir -p "$GEM_HOME" && chmod 777 "$GEM_HOME"
-# (BUNDLE_PATH = GEM_HOME, no need to mkdir/chown both)
-
-CMD [ "irb" ]

2.7-rc/buster/Dockerfile

@@ -1,4 +1,4 @@
-FROM buildpack-deps:stretch
+FROM buildpack-deps:buster
 
 # skip installing gem documentation
 RUN mkdir -p /usr/local/etc \

2.7-rc/buster/slim/Dockerfile

@@ -1,4 +1,4 @@
-FROM debian:stretch-slim
+FROM debian:buster-slim
 
 RUN apt-get update \
 	&& apt-get install -y --no-install-recommends \

generate-stackbrew-library.sh

@@ -6,7 +6,10 @@ declare -A aliases=(
 	[2.7-rc]='rc'
 )
 
-defaultDebianSuite='stretch'
+defaultDebianSuite='stretch' # TODO buster
+declare -A debianSuites=(
+	[2.7-rc]='buster'
+)
 defaultAlpineVersion='3.10'
 declare -A alpineVersion=(
 	#[2.3]='3.8'
@@ -76,7 +79,7 @@ join() {
 
 for version in "${versions[@]}"; do
 	for v in \
-		{stretch,jessie}{,/slim} \
+		{buster,stretch,jessie}{,/slim} \
 		alpine{3.10,3.9} \
 	; do
 		dir="$version/$v"
@@ -101,12 +104,13 @@ for version in "${versions[@]}"; do
 		)
 
 		variantAliases=( "${versionAliases[@]/%/-$variant}" )
+		debianSuite="${debianSuites[$version]:-$defaultDebianSuite}"
 		case "$variant" in
-			"$defaultDebianSuite")
+			"$debianSuite")
 				variantAliases+=( "${versionAliases[@]}" )
 				;;
-			*-"$defaultDebianSuite")
-				variantAliases+=( "${versionAliases[@]/%/-${variant%-$defaultDebianSuite}}" )
+			*-"$debianSuite")
+				variantAliases+=( "${versionAliases[@]/%/-${variant%-$debianSuite}}" )
 				;;
 			"alpine${alpineVersion[$version]:-$defaultAlpineVersion}")
 				variantAliases+=( "${versionAliases[@]/%/-alpine}" )

update.sh

@@ -72,7 +72,7 @@ for version in "${versions[@]}"; do
 
 	for v in \
 		alpine{3.9,3.10} \
-		{jessie,stretch}{/slim,} \
+		{jessie,stretch,buster}{/slim,} \
 	; do
 		dir="$version/$v"
 		variant="$(basename "$v")"