Allow build with specific Go version

Dockerfile

@@ -12,14 +12,6 @@ RUN apt-get update &&\
 RUN curl -L --fail https://get.docker.com/builds/Linux/x86_64/docker-1.10.3 -o /usr/local/bin/docker &&\
     chmod +x /usr/local/bin/docker
 
-# Installing from official packages makes it easier to bump Go version when distro lags
-# behind. For instance Debian is taking too long to upgrade to 1.5.3 which includes an
-# important security fix.
-RUN curl https://storage.googleapis.com/golang/go1.5.3.linux-amd64.tar.gz -o go.tar.gz &&\
-    tar -C /usr/local -xzf go.tar.gz &&\
-    rm -rf go.tar.gz &&\
-    mkdir /gopath
-
 ENV GOPATH /gopath
 
 ENV PATH $PATH:/usr/local/go/bin:/gopath/bin

README.md

@@ -84,8 +84,10 @@ dependencies from github and other public repositories supported by default,
 however, vendored dependencies should be preferred as they ensure repeatable
 build.
 
-gockerize uses Go 1.5.3 and enables [GOVENDOREXPERIMENT](https://docs.google.com/document/d/1Bz5-UB7g2uPBdOx-rw5t9MxJwkfpx90cqG9AFL0JAYo).
-
+By default, gockerize uses Go 1.5.3 and enables [GOVENDOREXPERIMENT](https://docs.google.com/document/d/1Bz5-UB7g2uPBdOx-rw5t9MxJwkfpx90cqG9AFL0JAYo).
+However, it is possible to use any desired version of Go by setting the `GOVERSION`
+environment variable appropriately, for instance `GOVERSION=1.9.2` to build with
+Go 1.9.2
 
 Patching standard lib
 ---------------------

gockerize

@@ -1,6 +1,6 @@
 #!/bin/bash
 #
-# Copyright (c) 2015, Air Computing Inc. <oss@aerofs.com>
+# Copyright (c) 2015-2017, Air Computing Inc. <oss@aerofs.com>
 # All rights reserved.
 
 set -e
@@ -33,7 +33,12 @@ else
 fi
 DOCKERFILE=${5:-/dev/null}
 
-BUILDER=aerofs/gockerize
+# TODO: auto-detect latest stable golang release
+# NB: stick to 1.5.3 by default for backwards compatibility
+GOVERSION=${GOVERSION:-1.5.3}
+BUILDER_PREFIX=aerofs/gockerize
+BUILDER_BASE=${BUILDER_PREFIX}.base
+BUILDER=${BUILDER_PREFIX}-${GOVERSION}
 THIS_DIR="$( cd "$(dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 source "$THIS_DIR/img_fresh.sh"
@@ -45,7 +50,16 @@ fi
 
 echo "Building $BUILDER ..."
 # build base builder container
-docker build -t $BUILDER "$THIS_DIR"
+docker build -t ${BUILDER_BASE} "$THIS_DIR"
+
+# build builder with specific go version
+docker build -t ${BUILDER} - <<EOF
+FROM ${BUILDER_BASE}
+RUN curl https://storage.googleapis.com/golang/go${GOVERSION}.linux-amd64.tar.gz -o go.tar.gz &&\
+    tar -C /usr/local -xzf go.tar.gz &&\
+    rm -rf go.tar.gz &&\
+    mkdir /gopath
+EOF
 
 tmpimg="${BUILDER}-$(echo "$IMAGE" | sed 's/\//./g')"
 echo "Building $tmpimg ..."
@@ -54,7 +68,7 @@ echo "Building $tmpimg ..."
 tmpfile="${SRC_DIR}/.gockerize.dockerfile"
 
 cat - > "$tmpfile" <<EOF
-FROM $BUILDER
+FROM ${BUILDER}
 COPY . /gopath/src/$DST_DIR
 EOF
 

root/run.sh

@@ -1,5 +1,4 @@
 #!/bin/bash
-
 set -e
 
 IMAGE=$1
@@ -15,13 +14,12 @@ fi
 
 # apply optional stdlib patches
 if [ -d "${GOPATH}/src/${SERVICE}/patches" ] ; then
-    pushd /usr/local/go/
+    pushd /usr/local/go/ >>/dev/null
     for p in ${GOPATH}/src/${SERVICE}/patches/*.patch ; do
         patch -p1 < $p
     done
-    popd
+    popd >>/dev/null
 fi
 
-CGO_ENABLED=0 GO15VENDOREXPERIMENT=1 go get $GOARGS -a -x -installsuffix cgo -ldflags '-d -s -w' ${SERVICE}
-docker build --no-cache -t ${IMAGE} -f ${DOCKERFILE} ${GOPATH}
-
+CGO_ENABLED=0 GO15VENDOREXPERIMENT=1 go get $GOARGS -a -installsuffix cgo -ldflags '-d -s -w' ${SERVICE}
+docker build -t ${IMAGE} -f ${DOCKERFILE} ${GOPATH}