TOOLS-2315 document how to add to /Joyent_Dev/public/releng/go/adhoc …

…for new go versions (#278)

Reviewed by: Trent Mick <trentm@gmail.com>

tools/releng/go-prebuilt/go-build.sh

@@ -0,0 +1,199 @@
+#!/bin/bash
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Copyright 2020 Joyent, Inc.
+#
+
+#
+# This script expects that you have downloaded and extracted a Go bootstrap
+# release from $GO_MANTA_URL and are running on a 'min_platform' SmartOS box.
+# It then expects to have a *.src.tar.gz release from $GO_SOURCE_URL and
+# have extracted it to a versioned directory at the top of your build dir.
+#
+# Then invoke using something like:
+#
+# $ ~/projects/triton.git/tools/releng/go-prebuilt/go-build.sh \
+#      -N 1.14 -b 1.13rc1 -d /ws/gobuild
+#
+#
+
+if [[ -n "$TRACE" ]]; then
+    export PS4='${BASH_SOURCE}:${LINENO}: '
+    set -o xtrace
+fi
+set -o errexit
+
+#
+# This URL is hardcoded in eng.git:tools/download_go. If it changes, be sure
+# to modify there too.
+#
+GO_MANTA_URL=https://us-east.manta.joyent.com/Joyent_Dev/public/releng/go/adhoc/
+
+#
+# The Golang source distribution download page
+#
+GO_SOURCE_URL=https://golang.org/dl/
+
+function usage {
+    echo ""
+    echo "Usage: go-build.sh [options]"
+    echo ""
+    echo "OPTIONS"
+    echo "  -b <version>        the bootstrap version to use"
+    echo "  -d <dir>            the top-level build directory"
+    echo "  -f                  force a build, ignoring min_platform and any existing output archive"
+    echo "  -N <version>        the new Golang version to build"
+    echo "  -C                  skip post-build cleanup and archive steps"
+    exit 2
+}
+
+function verify_min_platform {
+    MIN_PLATFORM=20181206T011455Z
+    CURRENT_PLATFORM=$(uname -v | sed -e 's/^joyent_//g')
+
+    if [[ "$CURRENT_PLATFORM" != "$MIN_PLATFORM" ]]; then
+        echo "The current platform $CURRENT_PLATFORM is not $MIN_PLATFORM"
+        echo "Golang builds for use in Triton/Manta should be done on the"
+        echo "oldest supported platform to ensure we're able to build with"
+        echo "it on any current build machine."
+        exit 1
+    fi
+}
+
+function build {
+    export GOROOT_BOOTSTRAP="$BUILD_DIR/$BOOTSTRAP_VER"
+    export GOROOT="$BUILD_DIR/$NEW_VER/proto"
+    export GOROOT_FINAL="/opt/go/$NEW_VER"
+    export GOOS='illumos'
+    export GOARCH='amd64'
+
+    cd "$BUILD_DIR/$NEW_VER/src"
+    echo "Building in dir: $(pwd)"
+    ./all.bash
+}
+
+function cleanup {
+    #
+    # Attempt to remove superfluous files to reduce the size
+    # of the Golang toolchain archive. This is based on code
+    # and comments in:
+    #     https://github.com/golang/build/blob/master/cmd/release/release.go
+    #
+    cd $BUILD_DIR/$NEW_VER
+
+    if [[ ! -f VERSION ]] || ! v=$(<VERSION) || [[ "$v" != "go${NEW_VER}" ]]; then
+        printf 'Are you in a go release directory?\n' >&2
+        exit 1
+    fi
+
+    # Remove the bootstrap compiler files.
+    rm -rf "pkg/bootstrap"
+
+    # Remove the obj build cache, which is _huge_.
+    rm -rf "pkg/obj"
+
+    # Remove the libraries used to build the toolchain commands.
+    rm -rf "pkg/illumos_amd64/cmd"
+}
+
+function compress {
+    cd $BUILD_DIR/$NEW_VER
+    gtar --owner=root --group=root -cvjf \
+        $BUILD_DIR/go${NEW_VER}.illumos-amd64.tar.bz2 \
+        *
+}
+
+#
+# Main
+#
+while getopts "Cb:d:fN:" opt; do
+    case "${opt}" in
+        d)
+            BUILD_DIR=$OPTARG
+            ;;
+        f)
+            FORCE=true
+            ;;
+        b)
+            BOOTSTRAP_VER=$OPTARG
+            ;;
+        C)
+            SKIP_CLEANUP=true
+            ;;
+        N)
+            NEW_VER=$OPTARG
+            ;;
+        *)
+            echo "Error: Unknown argument ${opt}"
+            usage
+    esac
+done
+shift $((OPTIND - 1))
+
+if [[ -z "${BUILD_DIR}" ]]; then
+    echo "Missing -d argument <build directory>"
+    usage
+fi
+
+if [[ -z "${BOOTSTRAP_VER}" ]]; then
+    echo "Missing -b argument <bootstrap version>"
+    usage
+fi
+
+if [[ -z "${NEW_VER}" ]]; then
+    echo "Missing -N argument <new version>"
+    usage
+fi
+
+if [[ ! -d ${BUILD_DIR}/${BOOTSTRAP_DIR} ]]; then
+    echo ""
+    echo "Missing bootstrap directory ${BUILD_DIR}/${BOOTSTRAP_DIR}"
+    echo "You should download and extract an appropriate bootstrap go build"
+    echo "from $GO_MANTA_URL"
+    exit 1
+fi
+
+mkdir -p $BUILD_DIR/$NEW_VER
+
+if [[ ! -f ${BUILD_DIR}/${NEW_VER}/VERSION ]]; then
+    #
+    # This message assumes that golang source releases
+    # are always packaged with ./go/ at the top level of
+    # the archive, which has always been the case so far.
+    #
+    echo ""
+    echo "Missing Golang sources in ${BUILD_DIR}/${NEW_VER}"
+    echo "You should download a go${NEW_VER}.src.tar.gz archive from"
+    echo "$GO_SOURCE_URL"
+    echo "verify its SHA256 checksum, then extract it with:"
+    echo ""
+    echo "    tar -C $BUILD_DIR/$NEW_VER -x --strip-components=1 -f $BUILD_DIR/go${NEW_VER}.src.tar.gz"
+    echo ""
+    exit 1
+fi
+
+if [[ -f $BUILD_DIR/go${NEW_VER}.illumos-amd64.tar.bz2 ]]; then
+    if [[ -z "$FORCE" ]]; then
+        echo "Use -f flag to remove existing archive at $BUILD_DIR/go${NEW_VER}.illumos-amd64.tar.bz2"
+        echo "Note that this also ignores the min_platform check, so should not be set for production builds."
+        exit 1
+    fi
+fi
+
+verify_min_platform
+build
+RES=$?
+if [[ -n "$SKIP_CLEANUP" ]]; then
+    echo "Skipping cleanup and archive stages."
+    exit $RES
+fi
+cleanup
+compress
+
+echo ""
+echo "All done. You should now test $BUILD_DIR/go${NEW_VER}.illumos-amd64.tar.bz2"
+echo "and then post it to $GO_MANTA_URL"
+echo ""