Merge pull request #700 from BenTheElder/go1127

upgrade to go 1.12.7, cleanup build scripts a bit

README.md

@@ -27,7 +27,7 @@ kind bootstraps each "node" with [kubeadm][kubeadm]. For more details see [the d
 
 You can install kind with `GO111MODULE="on" go get sigs.k8s.io/kind@v0.4.0`.
 
-**NOTE**: please use the latest go to do this, ideally go 1.12.6 or greater.
+**NOTE**: please use the latest go to do this, ideally go 1.12.7 or greater.
 
 This will put `kind` in `$(go env GOPATH)/bin`. If you encounter the error
 `kind: command not found` after installation then you may need to either add that directory to your `$PATH` as

hack/build/go_container.sh

@@ -18,49 +18,81 @@
 set -o nounset
 set -o errexit
 
-# get and go to the repo root
-REPO_ROOT="${REPO_ROOT:-$(git rev-parse --show-toplevel)}"
+# get the repo root for defaulting OUT_DIR and SOURCE_DIR
+# we assume the repo root is two levels up from this script
+REPO_ROOT="${REPO_ROOT:-$(cd "$(dirname "$0")/../.." && pwd)}"
 
-# autodetect host GOOS and GOARCH if not set, even if go is not installed
-GOOS="${GOOS:-$("${REPO_ROOT}/hack/build/goos.sh")}"
-GOARCH="${GOARCH:-$("${REPO_ROOT}/hack/build/goarch.sh")}"
-
-# use the official module proxy by default
+# ============================ SCRIPT SETTINGS =================================
+# output directory, will be mounted to /out, defaults to /bin in REPO_ROOT
+OUT_DIR="${OUT_DIR:-${REPO_ROOT}/bin}"
+# source directory, will be mounted to /src, defaults to REPO_ROOT
+SOURCE_DIR="${SOURCE_DIR:-${REPO_ROOT}}"
+# GOPROXY is respected by go, use the official module proxy by default
+# this helps make our build more reproducible and reliable
 GOPROXY="${GOPROXY:-https://proxy.golang.org}"
+# the container image, by default a recent official golang image
+GOIMAGE="${GOIMAGE:-golang:1.12.7}"
+# ========================== END SCRIPT SETTINGS ===============================
 
-# default build image
-GO_VERSION="1.12.6"
-GO_IMAGE="golang:${GO_VERSION}"
+# autodetects and host GOOS and GOARCH and sets them if not set
+# works even if go is not installed on the host
+detect_and_set_goos_goarch() {
+  # if we have go, just ask go! NOTE: this respects explicitly set GOARCH / GOOS
+  if which go >/dev/null 2>&1; then
+    GOARCH=$(go env GOARCH)
+    GOOS=$(go env GOOS)
+    return
+  fi
 
-# docker volume name, used as a go module / build cache
-CACHE_VOLUME="kind-build-cache"
+  # detect GOOS equivalent if unset
+  if [ -z "${GOOS:-}" ]; then
+    case "$(uname -s)" in
+      Darwin) GOOS="darwin" ;;
+      Linux) GOOS="linux" ;;
+      *) echo "Unknown host OS! '$(uname -s)'" exit 2 ;;
+    esac
+  fi
 
-# output directory
-OUT_DIR="${OUT_DIR:-${REPO_ROOT}/bin}"
-# source directory
-SOURCE_DIR="${SOURCE_DIR:-${REPO_ROOT}}"
+  # detect GOARCH equivalent if unset
+  if [ -z "${GOARCH:-}" ]; then
+    case "$(uname -m)" in
+      x86_64) GOARCH="amd64" ;;
+      arm*)
+        GOARCH="arm"
+        if [ "$(getconf LONG_BIT)" = "64" ]; then
+          GOARCH="arm64"
+        fi
+      ;;
+      *) echo "Unknown host architecture! '$(uname -m)'" exit 2 ;;
+    esac
+  fi
+}
 
 # creates the output directory
 make_out_dir() {
   mkdir -p "${OUT_DIR}"
 }
 
+# docker volume name, used as a go module / build cache
+__CACHE_VOLUME__="kind-build-cache"
+
 # creates the cache volume
 make_cache_volume() {
-  docker volume create "${CACHE_VOLUME}" >/dev/null
+  docker volume create "${__CACHE_VOLUME__}" >/dev/null
 }
 
 # runs $@ in a go container with caching etc. and the repo mount to /src
 run_in_go_container() {
-  # get user id and group id so we can run the container
+  # get host user id and group id so we can run the container as them
+  # this ensures sane file ownership for build outputs
   _UID=$(id -u)
   _GID=$(id -g)
   # run in the container
   docker run \
     `# ensure the container is removed on exit` \
       --rm \
     `# use the cache volume for go` \
-      -v "${CACHE_VOLUME}:/go" \
+      -v "${__CACHE_VOLUME__}:/go" \
       -e GOCACHE=/go/cache \
     `# mount the output & repo dir, set working directory to the repo` \
       -v "${OUT_DIR}:/out" \
@@ -79,11 +111,12 @@ run_in_go_container() {
     `# run as if the host user for consistent file permissions` \
       --user "${_UID}:${_GID}" \
     `# use the golang image for the container` \
-      "${GO_IMAGE}" \
+      "${GOIMAGE}" \
     `# and finally, pass through args` \
       "$@"
 }
 
 make_out_dir
 make_cache_volume
+detect_and_set_goos_goarch
 run_in_go_container "$@"

hack/build/goinstalldir.sh

@@ -14,6 +14,8 @@
 # limitations under the License.
 
 # this utility prints out the golang install dir, even if go is not installed
+# IE it prints the directory where `go install ...` would theoretically place
+# binaries
 
 # if we have go, just ask go!
 if which go >/dev/null 2>&1; then

site/content/docs/contributing/getting-started.md

@@ -51,7 +51,7 @@ You can check if Go is in your system with the following command:
 go version
 ```
 
-Preferably Go `1.12.6` or greater should be installed. 
+Preferably Go `1.12.7` or greater should be installed. 
 
 Correct automatic formatting of the source with `gofmt` requires at least
 `1.11.0`.

site/content/docs/user/quick-start.md

@@ -17,7 +17,7 @@ This guide covers getting started with the `kind` command.
 You can either install kind with `GO111MODULE="on" go get sigs.k8s.io/kind@v0.4.0` or clone this repo 
 and run `make build` from the repository.
 
-**NOTE**: please use the latest go to do this, ideally go 1.12.6 or greater.
+**NOTE**: please use the latest go to do this, ideally go 1.12.7 or greater.
 
 This will put `kind` in `$(go env GOPATH)/bin`. You may need to add that directory to your `$PATH` as
 shown [here](https://golang.org/doc/code.html#GOPATH) if you encounter the error