improve repo tooling

Makefile

@@ -36,7 +36,7 @@ all: build
 
 # builds kind in a container, outputs to $(OUT_DIR)
 kind:
-	hack/build/go_container.sh go build -v -o /out/$(KIND_BINARY_NAME)
+	hack/go_container.sh go build -v -o /out/$(KIND_BINARY_NAME)
 
 # alias for building kind
 build: kind

hack/go_container.sh

@@ -0,0 +1,93 @@
+#!/bin/sh
+# Copyright 2019 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Simple posix sh reproducible go build container script with caching.
+#
+# Usage:
+#  hack/go_container.sh go version
+#  hack/go_container.sh go build -o /out/kind .
+set -o nounset -o errexit
+
+# ============================ SCRIPT SETTINGS =================================
+# get the repo root for defaulting OUT_DIR and SOURCE_DIR
+REPO_ROOT="${REPO_ROOT:-$(cd "$(dirname "$0")/.." && pwd)}"
+# output directory, will be mounted to /out, defaults to /bin in REPO_ROOT
+OUT_DIR="${OUT_DIR:-${REPO_ROOT}/bin}"
+# source directory, will be mounted to /src, defaults to current directory
+SOURCE_DIR="${SOURCE_DIR:-$(pwd -P)}"
+# default to disabling CGO for easier reproducible builds and cross compilation
+export CGO_ENABLED="${CGO_ENABLED:-0}"
+# the container image, by default a recent official golang image
+GOIMAGE="${GOIMAGE:-golang:1.13rc1}"
+# docker volume name, used as a go module / build cache
+CACHE_VOLUME="${CACHE_VOLUME:-kind-build-cache}"
+# ========================== END SCRIPT SETTINGS ===============================
+
+# autodetects host GOOS and GOARCH and exports them if not set
+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)
+  fi
+
+  # detect GOOS equivalent if unset
+  if [ -z "${GOOS:-}" ]; then
+    case "$(uname -s)" in
+      Darwin) export GOOS="darwin" ;;
+      Linux) export GOOS="linux" ;;
+      *) echo "Unknown host OS! '$(uname -s)'" exit 2 ;;
+    esac
+  fi
+
+  # detect GOARCH equivalent if unset
+  if [ -z "${GOARCH:-}" ]; then
+    case "$(uname -m)" in
+      x86_64) export GOARCH="amd64" ;;
+      arm*)
+        export GOARCH="arm"
+        if [ "$(getconf LONG_BIT)" = "64" ]; then
+          export GOARCH="arm64"
+        fi
+      ;;
+      *) echo "Unknown host architecture! '$(uname -m)'" exit 2 ;;
+    esac
+  fi
+
+  export GOOS GOARCH
+}
+
+# runs $@ in a go container with caching etc.
+run_in_go_container() {
+  # run in the container
+  docker run \
+    `# docker options: remove container on exit, run as the host user / group` \
+      --rm --user "$(id -u):$(id -g)" \
+    `# golang caching: mount and use the cache volume` \
+      -v "${CACHE_VOLUME}:/go" -e GOCACHE=/go/cache \
+    `# mount the output & source dir, set working directory to the source dir` \
+      -v "${OUT_DIR}:/out" -v "${SOURCE_DIR}:/src" -w "/src" \
+    `# pass through go settings: modules, proxy, cgo, OS / Arch` \
+      -e GO111MODULE -e GOPROXY -e CGO_ENABLED -e GOOS -e GOARCH \
+    `# pass through proxy settings` \
+      -e HTTP_PROXY -e HTTPS_PROXY -e NO_PROXY \
+    `# run the image with the args passed to this script` \
+      "${GOIMAGE}" "$@"
+}
+
+mkdir -p "${OUT_DIR}"
+docker volume create "${CACHE_VOLUME}" >/dev/null
+detect_and_set_goos_goarch
+run_in_go_container "$@"

images/kindnetd/build.sh

@@ -27,7 +27,7 @@ export GOOS="linux"
 export SOURCE_DIR="${REPO_ROOT}/cmd/kindnetd"
 # NOTE: use a per-arch OUT_DIR so we send less in the docker build context
 export OUT_DIR="${REPO_ROOT}/bin/kindnetd/${GOARCH}"
-hack/build/go_container.sh go build -v -o /out/kindnetd
+hack/go_container.sh go build -v -o /out/kindnetd
 
 # TODO: verisoning
 # build image