Add stretch variant for 1.13

.travis.yml

@@ -8,6 +8,8 @@ matrix:
       env: VERSION=1.13 VARIANT=windows/windowsservercore-1803
     - os: linux
       env: VERSION=1.13 VARIANT=buster
+    - os: linux
+      env: VERSION=1.13 VARIANT=stretch
     - os: linux
       env: VERSION=1.13 VARIANT=alpine3.10
     - os: windows

1.13/stretch/Dockerfile

@@ -0,0 +1,50 @@
+FROM buildpack-deps:stretch-scm
+
+# gcc for cgo
+RUN apt-get update && apt-get install -y --no-install-recommends \
+		g++ \
+		gcc \
+		libc6-dev \
+		make \
+		pkg-config \
+	&& rm -rf /var/lib/apt/lists/*
+
+ENV GOLANG_VERSION 1.13
+
+RUN set -eux; \
+	\
+# this "case" statement is generated via "update.sh"
+	dpkgArch="$(dpkg --print-architecture)"; \
+	case "${dpkgArch##*-}" in \
+		amd64) goRelArch='linux-amd64'; goRelSha256='68a2297eb099d1a76097905a2ce334e3155004ec08cdea85f24527be3c48e856' ;; \
+		armhf) goRelArch='linux-armv6l'; goRelSha256='931906d67cae1222f501e7be26e0ee73ba89420be0c4591925901cb9a4e156f0' ;; \
+		arm64) goRelArch='linux-arm64'; goRelSha256='e2a61328101eff3b9c1ba47ecfec5eb2fdc3eb35d8c27d505737ba98bfcb197b' ;; \
+		i386) goRelArch='linux-386'; goRelSha256='519b3e6ae4db011b93b60e6fabb055773ae6448355b6909a6befef87e02d98f5' ;; \
+		ppc64el) goRelArch='linux-ppc64le'; goRelSha256='807b036bb058061b6090635e2a8612aaf301895dce70a773bbcd67fa1e57337c' ;; \
+		s390x) goRelArch='linux-s390x'; goRelSha256='b7122795910b70b68e4118d0d34685a30925f4dd861c065cf20b699a7783807a' ;; \
+		*) goRelArch='src'; goRelSha256='3fc0b8b6101d42efd7da1da3029c0a13f22079c0c37ef9730209d8ec665bf122'; \
+			echo >&2; echo >&2 "warning: current architecture ($dpkgArch) does not have a corresponding Go binary release; will be building from source"; echo >&2 ;; \
+	esac; \
+	\
+	url="https://golang.org/dl/go${GOLANG_VERSION}.${goRelArch}.tar.gz"; \
+	wget -O go.tgz "$url"; \
+	echo "${goRelSha256} *go.tgz" | sha256sum -c -; \
+	tar -C /usr/local -xzf go.tgz; \
+	rm go.tgz; \
+	\
+	if [ "$goRelArch" = 'src' ]; then \
+		echo >&2; \
+		echo >&2 'error: UNIMPLEMENTED'; \
+		echo >&2 'TODO install golang-any from jessie-backports for GOROOT_BOOTSTRAP (and uninstall after build)'; \
+		echo >&2; \
+		exit 1; \
+	fi; \
+	\
+	export PATH="/usr/local/go/bin:$PATH"; \
+	go version
+
+ENV GOPATH /go
+ENV PATH $GOPATH/bin:/usr/local/go/bin:$PATH
+
+RUN mkdir -p "$GOPATH/src" "$GOPATH/bin" && chmod -R 777 "$GOPATH"
+WORKDIR $GOPATH