💝 Vendorless codegen via shell scripting (#386)

* Vendorless codegen in a hacky way

* Support for Go 1.22 go work vendor command

* Fix codegen cleanup

* Remove the go work vendor dir for now, by switch back to go 1.21

* Add the auto-generated code

* Working tests

* Better clean up of codegen

* Adding verify-codegen script

* Fix the unit tests

* Fixing the fluke test

by relaxing the stderr checks

* Relaxing checks for stderr to not fail on download lines

* Mock truncate of go.work.sum to avoid removing it after tests

* Restore the original GOPATH if a custom one was set

* Shorter way of redirecting all output to /dev/null

boilerplate.go.txt

@@ -0,0 +1,15 @@
+/*
+Copyright #{YEAR} The Knative 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.
+*/

codegen-library.sh

@@ -16,21 +16,156 @@
 
 # Setup the env for doing Knative style codegen.
 
-kn_hack_library=${kn_hack_library:-"$(dirname $0)/../vendor/knative.dev/hack/library.sh"}
+# Store Bash options
+oldstate="$(set +o)"
+
+set -Eeuo pipefail
+
+export repodir kn_hack_dir kn_hack_library \
+  MODULE_NAME CODEGEN_TMP_GOPATH CODEGEN_ORIGINAL_GOPATH GOPATH GOBIN \
+  CODEGEN_PKG KNATIVE_CODEGEN_PKG
+
+kn_hack_dir="$(realpath "$(dirname "${BASH_SOURCE[0]:-$0}")")"
+kn_hack_library=${kn_hack_library:-"${kn_hack_dir}/library.sh"}
 
 if [[ -f "$kn_hack_library" ]]; then
-  source $kn_hack_library
+  # shellcheck disable=SC1090
+  source "$kn_hack_library"
 else
-  echo "this file is intended to be imported from a golang project that vendors knative.dev/hack"
-  exit
+  echo "The \$kn_hack_library points to a non-existent file: $kn_hack_library" >&2
+  exit 42
 fi
 
-export MODULE_NAME=$(go_mod_module_name)
-export GOPATH=$(go_mod_gopath_hack)
-export GOBIN=${GOPATH}/bin # Set GOBIN explicitly as deepcopy-gen is installed by go install.
-export CODEGEN_PKG=${CODEGEN_PKG:-$(cd ${REPO_ROOT_DIR}; ls -d -1 ./vendor/k8s.io/code-generator 2>/dev/null || echo ../code-generator)}
-export KNATIVE_CODEGEN_PKG=${KNATIVE_CODEGEN_PKG:-$(cd ${REPO_ROOT_DIR}; ls -d -1 ./vendor/knative.dev/pkg 2>/dev/null || echo "${REPO_ROOT_DIR}")}
+repodir="$(go_run knative.dev/toolbox/modscope@latest current --path)"
+
+function go-resolve-pkg-dir() {
+  local pkg="${1:?Pass the package name}"
+  local pkgdir
+  if [ -d "${repodir}/vendor" ]; then
+    pkgdir="${repodir}/vendor/${pkg}"
+    if [ -d "${pkgdir}" ]; then
+      echo "${pkgdir}"
+      return 0
+    else
+      return 1
+    fi
+  else
+    go mod download -x > /dev/stderr
+    go list -m -f '{{.Dir}}' "${pkg}" 2>/dev/null
+    return $?
+  fi
+}
+
+# Change dir to the original executing script's directory, not the current source!
+pushd "$(dirname "$(realpath "$0")")" > /dev/null
+
+if ! CODEGEN_PKG="${CODEGEN_PKG:-"$(go-resolve-pkg-dir k8s.io/code-generator)"}"; then
+  warning "Failed to determine the k8s.io/code-generator package"
+fi
+if ! KNATIVE_CODEGEN_PKG="${KNATIVE_CODEGEN_PKG:-"$(go-resolve-pkg-dir knative.dev/pkg)"}"; then
+  warning "Failed to determine the knative.dev/pkg package"
+fi
+
+popd > /dev/null
+
+CODEGEN_ORIGINAL_GOPATH="$(go env GOPATH)"
+CODEGEN_TMP_GOPATH=$(go_mod_gopath_hack)
+GOPATH="${CODEGEN_TMP_GOPATH}"
+GOBIN="${GOPATH}/bin" # Set GOBIN explicitly as k8s-gen' are installed by go install.
+
+if [[ -n "${CODEGEN_PKG}" ]] && ! [ -x "${CODEGEN_PKG}/generate-groups.sh" ]; then
+  chmod +x "${CODEGEN_PKG}/generate-groups.sh"
+  chmod +x "${CODEGEN_PKG}/generate-internal-groups.sh"
+fi
+if [[ -n "${KNATIVE_CODEGEN_PKG}" ]] && ! [ -x "${KNATIVE_CODEGEN_PKG}/hack/generate-knative.sh" ]; then
+  chmod +x "${KNATIVE_CODEGEN_PKG}/hack/generate-knative.sh"
+fi
+
+# Generate boilerplate file with the current year
+function boilerplate() {
+  local go_header_file="${kn_hack_dir}/boilerplate.go.txt"
+  local current_boilerplate_file="${TMPDIR}/boilerplate.go.txt"
+  # Replace #{YEAR} with the current year
+  sed "s/#{YEAR}/$(date +%Y)/" \
+    < "${go_header_file}" \
+    > "${current_boilerplate_file}"
+  echo "${current_boilerplate_file}"
+}
+
+# Generate K8s' groups codegen
+function generate-groups() {
+  if [[ -z "${CODEGEN_PKG}" ]]; then
+    abort "CODEGEN_PKG is not set"
+  fi
+  "${CODEGEN_PKG}"/generate-groups.sh \
+    "$@" \
+    --go-header-file "$(boilerplate)"
+}
+
+# Generate K8s' internal groups codegen
+function generate-internal-groups() {
+  if [[ -z "${CODEGEN_PKG}" ]]; then
+    abort "CODEGEN_PKG is not set"
+  fi
+  "${CODEGEN_PKG}"/generate-internal-groups.sh \
+    "$@" \
+    --go-header-file "$(boilerplate)"
+}
+
+# Generate Knative style codegen
+function generate-knative() {
+  if [[ -z "${KNATIVE_CODEGEN_PKG}" ]]; then
+    abort "KNATIVE_CODEGEN_PKG is not set"
+  fi
+  "${KNATIVE_CODEGEN_PKG}/hack/generate-knative.sh" \
+    "$@" \
+    --go-header-file "$(boilerplate)"
+}
+
+# Cleanup after generating code
+function cleanup-codegen() {
+  restore-changes-if-its-copyright-year-only
+  restore-gopath
+}
+
+# Restore changes if the file contains only the change in the copyright year
+function restore-changes-if-its-copyright-year-only() {
+  local difflist
+  log "Cleaning up generated code"
+  difflist="$(mktemp)"
+  git diff --exit-code --name-only > "$difflist"
+  # list git changes and skip those which differ only in the boilerplate year
+  while read -r file; do
+    # check if the file contains just the change in the boilerplate year
+    if [ "$(LANG=C git diff --exit-code --shortstat -- "$file")" = ' 1 file changed, 1 insertion(+), 1 deletion(-)' ] && \
+        [[ "$(git diff --exit-code -U1 -- "$file" | grep -Ec '^[+-]\s*[*#]?\s*Copyright 2[0-9]{3}')" -eq 2 ]]; then
+      # restore changes to that file
+      git checkout -- "$file"
+    fi
+  done < "$difflist"
+  rm -f "$difflist"
+}
+
+# Restore the GOPATH and clean up the temporary directory
+function restore-gopath() {
+  # Skip this if the directory is already checked out onto the GOPATH.
+  if __is_checkout_onto_gopath; then
+    return
+  fi
+  if [ -d "$CODEGEN_TMP_GOPATH" ]; then
+    chmod -R u+w "${CODEGEN_TMP_GOPATH}"
+    rm -rf "${CODEGEN_TMP_GOPATH}"
+    unset CODEGEN_TMP_GOPATH
+  fi
+  unset GOPATH GOBIN
+  # Restore the original GOPATH, if it was different from the default one.
+  if [ "$CODEGEN_ORIGINAL_GOPATH" != "$(go env GOPATH)" ]; then
+    export GOPATH="$CODEGEN_ORIGINAL_GOPATH"
+  fi
+  unset CODEGEN_ORIGINAL_GOPATH
+}
+
+add_trap cleanup-codegen EXIT
 
-[ -x ${CODEGEN_PKG}/generate-groups.sh ] || chmod +x ${CODEGEN_PKG}/generate-groups.sh
-[ -x ${CODEGEN_PKG}/generate-internal-groups.sh ] || chmod +x ${CODEGEN_PKG}/generate-internal-groups.sh
-[ -x ${KNATIVE_CODEGEN_PKG}/hack/generate-knative.sh ] || chmod +x ${KNATIVE_CODEGEN_PKG}/hack/generate-knative.sh
+# Restore Bash options
+eval "$oldstate"

embed.go

@@ -20,5 +20,5 @@ import (
 	"embed"
 )
 
-//go:embed *.sh
+//go:embed *.sh *.go.txt
 var Scripts embed.FS

go.mod

@@ -1,3 +1,3 @@
 module knative.dev/hack
 
-go 1.18
+go 1.21

go.work

@@ -1,4 +1,4 @@
-go 1.18
+go 1.21
 
 use (
 	.