Build relevant binaries with coverage.

hack/lib/golang.sh

@@ -211,6 +211,15 @@ readonly KUBE_STATIC_LIBRARIES=(
   kubectl
 )
 
+# Fully-qualified package names that we want to instrument for coverage information.
+readonly KUBE_COVERAGE_INSTRUMENTED_PACKAGES=(
+  k8s.io/kubernetes/cmd/kube-apiserver
+  k8s.io/kubernetes/cmd/kube-controller-manager
+  k8s.io/kubernetes/cmd/kube-scheduler
+  k8s.io/kubernetes/cmd/kube-proxy
+  k8s.io/kubernetes/cmd/kubelet
+)
+
 # KUBE_CGO_OVERRIDES is a space-separated list of binaries which should be built
 # with CGO enabled, assuming CGO is supported on the target platform.
 # This overrides any entry in KUBE_STATIC_LIBRARIES.
@@ -441,6 +450,104 @@ kube::golang::outfile_for_binary() {
   echo "${output_path}/${bin}"
 }
 
+# Argument: the name of a Kubernetes package.
+# Returns 0 if the binary can be built with coverage, 0 otherwise.
+# NB: this ignores whether coverage is globally enabled or not.
+kube::golang::is_covered_binary() {
+  return $(kube::util::array_contains "$1" "${KUBE_COVERAGE_INSTRUMENTED_PACKAGES[@]}")
+}
+
+# Argument: the name of a Kubernetes package (e.g. k8s.io/kubernetes/cmd/kube-scheduler)
+# Echos the path to a dummy test used for coverage information.
+kube::golang::path_for_coverage_dummy_test() {
+	local package=$1
+  local path="${KUBE_GOPATH}/src/$package"
+  local name=$(basename "$package")
+  echo "$path/zz_autogenerated_${name}_test.go"
+}
+
+# Argument: the name of a Kubernetes package (e.g. k8s.io/kubernetes/cmd/kube-scheduler).
+# Creates a dummy unit test on disk in the source directory for the given package.
+# This unit test will invoke the package's standard entry point when run.
+kube::golang::create_coverage_dummy_test() {
+  local package="$1"
+  local name="$(basename "$package")"
+  cat <<EOF > $(kube::golang::path_for_coverage_dummy_test "$package")
+package main
+ import (
+  "flag"
+	"os"
+	"strconv"
+	"testing"
+	"time"
+)
+ func TestMain(m *testing.M) {
+  // We need to pass coverage instructions to the unittest framework, so we hijack os.Args
+  original_args := os.Args
+  now := time.Now().UnixNano()
+  test_args := []string{os.Args[0], "-test.coverprofile=/tmp/k8s-${name}-" + strconv.FormatInt(now, 10) + ".cov"}
+  os.Args = test_args
+
+  // This is sufficient for the unit tests to be set up.
+  flag.Parse()
+
+   // Restore the original args for use by the program.
+	os.Args = original_args
+ 	// Go!
+  main()
+
+   // Make sure we actually write the profiling information to disk, if we make it here.
+  // On long-running services, or anything that calls os.Exit(), this is insufficient,
+  // so be sure to call this from inside the binary too.
+  // TODO: actually have some code here.
+}
+EOF
+}
+
+# Argument: the name of a Kubernetes package (e.g. k8s.io/kubernetes/cmd/kube-scheduler).
+# Deletes a test generated by kube::golang::create_coverage_dumy_test.
+kube::golang::delete_coverage_dummy_test() {
+  local package=$1
+  rm $(kube::golang::path_for_coverage_dummy_test "$package")
+}
+
+# Arguments: a list of kubernetes packages to build.
+# Expected variables: build_args should be set to an array of Go build arguments.
+# In addition, the standard build globals are assumed.
+#
+# Invokes Go to actually build some packages. If coverage is disabled, simply invokes
+# go install. If coverage is enabled, builds covered binaries using go test, temporarily
+# producing the required unit test files and then cleaning up after itself.
+# Non-covered binaries are then built using go install as usual.
+kube::golang::build_some_binaries() {
+  if [[ -n "${build_with_coverage:-}" ]]; then
+    local -a uncovered=()
+    for package in "$@"; do
+      if kube::golang::is_covered_binary "$package"; then
+        V=2 kube::log::info "Building $package with coverage..."
+        kube::golang::create_coverage_dummy_test "$package"
+        go test -c -o "$(kube::golang::outfile_for_binary "$package" "$platform")" \
+          -covermode count \
+          -coverpkg k8s.io/... \
+          "${build_args[@]}" \
+          "$package"
+        kube::golang::delete_coverage_dummy_test "$package"
+      else
+        uncovered+=("$package")
+      fi
+    done
+    if [[ "${#uncovered[@]}" != 0 ]]; then
+      V=2 kube::log::info "Building ${uncovered[@]} without coverage..."
+      go install "${build_args[@]}" "${uncovered[@]}"
+    else
+      V=2 kube::log::info "Nothing to build without coverage."
+     fi
+   else
+    V=2 kube::log::info "Coverage is disabled."
+    go install "${build_args[@]}" "$@"
+   fi
+}
+
 kube::golang::build_binaries_for_platform() {
   local platform=$1
 
@@ -460,18 +567,24 @@ kube::golang::build_binaries_for_platform() {
     fi
   done
 
+  local -a build_args
   if [[ "${#statics[@]}" != 0 ]]; then
-    CGO_ENABLED=0 go install -installsuffix static "${goflags[@]:+${goflags[@]}}" \
-      -gcflags "${gogcflags}" \
-      -ldflags "${goldflags}" \
-      "${statics[@]:+${statics[@]}}"
+    build_args=(
+      -installsuffix static
+      ${goflags:+"${goflags[@]}"}
+      -gcflags "${gogcflags:-}"
+      -ldflags "${goldflags:-}"
+    )
+    CGO_ENABLED=0 kube::golang::build_some_binaries "${statics[@]}"
   fi
 
   if [[ "${#nonstatics[@]}" != 0 ]]; then
-    go install "${goflags[@]:+${goflags[@]}}" \
-      -gcflags "${gogcflags}" \
-      -ldflags "${goldflags}" \
-      "${nonstatics[@]:+${nonstatics[@]}}"
+    build_args=(
+      ${goflags:+"${goflags[@]}"}
+      -gcflags "${gogcflags:-}"
+      -ldflags "${goldflags:-}"
+    )
+    kube::golang::build_some_binaries "${nonstatics[@]}"
   fi
 
   for test in "${tests[@]:+${tests[@]}}"; do
@@ -480,9 +593,9 @@ kube::golang::build_binaries_for_platform() {
 
     mkdir -p "$(dirname ${outfile})"
     go test -c \
-      "${goflags[@]:+${goflags[@]}}" \
-      -gcflags "${gogcflags}" \
-      -ldflags "${goldflags}" \
+      ${goflags:+"${goflags[@]}"} \
+      -gcflags "${gogcflags:-}" \
+      -ldflags "${goldflags:-}" \
       -o "${outfile}" \
       "${testpkg}"
   done
@@ -535,10 +648,11 @@ kube::golang::build_binaries() {
     host_platform=$(kube::golang::host_platform)
 
     # Use eval to preserve embedded quoted strings.
-    local goflags goldflags gogcflags
+    local goflags goldflags gogcflags build_with_coverage
     eval "goflags=(${GOFLAGS:-})"
     goldflags="${GOLDFLAGS:-} $(kube::version::ldflags)"
     gogcflags="${GOGCFLAGS:-}"
+    build_with_coverage="${KUBE_BUILD_WITH_COVERAGE:-}"
 
     local -a targets=()
     local arg

hack/lib/util.sh

@@ -18,6 +18,20 @@ kube::util::sortable_date() {
   date "+%Y%m%d-%H%M%S"
 }
 
+# arguments: target, item1, item2, item3, ...
+# returns 0 if target is in the given items, 1 otherwise.
+kube::util::array_contains() {
+  local search="$1"
+  local element
+  shift
+  for element; do
+    if [[ "$element" == "$search" ]]; then
+      return 0
+     fi
+  done
+  return 1
+}
+
 kube::util::wait_for_url() {
   local url=$1
   local prefix=${2:-}