Instructions and script for go-yaml fork

kyaml/Makefile

@@ -40,10 +40,7 @@ lint: $(MYGOBIN)/golangci-lint
 
 
 license: $(MYGOBIN)/addlicense
-	$(MYGOBIN)/addlicense \
-	  -y 2021 \
-	  -c "The Kubernetes Authors." \
-	  -f LICENSE_TEMPLATE .
+	( find . -type f -not -path "*/internal/forked/github.com/go-yaml*" -exec bash -c "$(MYGOBIN)/addlicense -y 2021 -c 'The Kubernetes Authors.' -f LICENSE_TEMPLATE {}" ";" )
 
 test:
 	go test -cover ./...
@@ -52,10 +49,10 @@ fix:
 	go fix ./...
 
 fmt:
-	go fmt ./...
+	go fmt $(shell go list ./... | grep -v "/kyaml/internal/forked/github.com/go-yaml/yaml")
 
 tidy:
 	go mod tidy
 
 vet:
-	go vet ./...
+	go vet $(shell go list ./... | grep -v "/kyaml/internal/forked/github.com/go-yaml/yaml")

kyaml/internal/forked/README.md

@@ -0,0 +1,11 @@
+# kyaml internal forks
+
+## qri-io/starlib
+
+This code is used by the starlark runtime. We copied it in to reduce the dependencies being brought over to kubectl by the kustomize integration. Should it need updating, do so via manual copy-paste.
+
+## go-yaml/yaml
+
+This code is used extensively by kyaml. It is a copy of upstream at a particular revision that kubectl is using, with [a change we need](https://github.com/go-yaml/yaml/pull/753) cherry-picked on top. For background information on this problem, see https://github.com/kubernetes-sigs/kustomize/issues/3946.
+
+This copy was created using the [git subtree technique](https://medium.com/@porteneuve/mastering-git-subtrees-943d29a798ec) and can be recreated on top of a new version of go-yaml v3 using the [update-go-yaml.sh](update-go-yaml.sh) script. Please note that there is nothing special about the fork directory, so copy-paste with manual edits will work just fine if you prefer.

kyaml/internal/forked/update-go-yaml.sh

@@ -0,0 +1,106 @@
+#!/bin/bash
+# Copyright 2021 The Kubernetes Authors.
+# SPDX-License-Identifier: Apache-2.0
+
+set -euo pipefail
+
+if [ "$#" -ne 1 ]; then
+     echo "Usage: $0 \$GOYAML_V3_SHA"
+     exit 1
+ fi
+
+if [ "$(git branch --show-current)" == "master" ]; then
+  echo "You must be on a branch to use this script."
+  exit 1
+fi
+
+blue=$(tput setaf 4)
+normal=$(tput sgr0)
+
+# This should be the version of go-yaml v3 used by kubectl
+ # In the original fork, this is 496545a6307b2a7d7a710fd516e5e16e8ab62dbc
+ export GOYAML_SHA=$1
+ export GOYAML_REF="goyaml-$GOYAML_SHA"
+
+# The PRs we need to cherry-pick onto the above commit
+declare -r GO_YAML_PR=753
+declare -r KUSTOMIZE_PR=4004
+
+REPO_ROOT=$(git rev-parse --show-toplevel)
+declare -r REPO_ROOT
+declare -r REBASEMAGIC="${REPO_ROOT}/.git/rebase-apply"
+
+function explain() {
+    printf "\n\n%s\n" "${blue}$1${normal}"
+}
+
+# cherry-pick REPO PR
+function cherry-pick(){
+  repo=$1
+  pull=$2
+  echo "+++ Downloading patch to /tmp/${pull}.patch (in case you need to do this again)"
+
+  curl -o "/tmp/${pull}.patch" -sSL "${repo}/pull/${pull}.patch"
+  echo
+  echo "+++ About to attempt cherry pick of PR. To reattempt:"
+  echo "  $ git am -x -X subtree=kyaml/internal/forked/github.com/go-yaml/yaml -3 /tmp/${pull}.patch"
+  echo
+  git am -3 "/tmp/${pull}.patch" || {
+    conflicts=false
+    while unmerged=$(git status --porcelain | grep ^U) && [[ -n ${unmerged} ]] \
+      || [[ -e "${REBASEMAGIC}" ]]; do
+      conflicts=true # <-- We should have detected conflicts once
+      echo
+      explain "+++ Conflicts detected:"
+      echo
+      (git status --porcelain | grep ^U) || echo "!!! None. Did you git am --continue?"
+      echo
+      explain "+++ Please resolve the conflicts in another window (and remember to 'git add / git am --continue')"
+      read -p "+++ Proceed (anything but 'y' aborts the cherry-pick)? [y/n] " -r
+      echo
+      if ! [[ "${REPLY}" =~ ^[yY]$ ]]; then
+        explain "Aborting." >&2
+        exit 1
+      fi
+    done
+
+    if [[ "${conflicts}" != "true" ]]; then
+      explain "!!! git am failed, likely because of an in-progress 'git am' or 'git rebase'"
+      exit 1
+    fi
+  }
+
+  # remove the patch file from /tmp
+  rm -f "/tmp/${pull}.patch"
+}
+
+subtree_commit_flag=""
+
+explain "Removing the fork's tree from git, if it exists. We'll write over this commit in a moment, but \`read-tree\` requires a clean directory."
+if [[ $(find  kyaml/internal/forked/github.com/go-yaml/yaml -type f -delete) ]]; then
+  git commit --all -m "Temporarily remove go-yaml fork"
+  subtree_commit_flag="--amend"
+fi
+
+explain "Fetching the version of go-yaml used by kubectl. Tag it more explicitly in case of conflicts with commits local to this repo."
+git fetch --depth=1 https://github.com/go-yaml/yaml.git "$GOYAML_SHA:$GOYAML_REF"
+
+explain "Inserting the content we just pulled as a subtree of this repository and squash the changes into the last commit."
+git read-tree --prefix=kyaml/internal/forked/github.com/go-yaml/yaml/ -u "$GOYAML_REF"
+git commit $subtree_commit_flag --all -m "Internal copy of go-yaml at $GOYAML_SHA"
+
+explain "Subtree creation successful."
+
+explain "Cherry-picking the commits from our go-yaml/yaml PR"
+cherry-pick https://github.com/go-yaml/yaml $GO_YAML_PR
+
+explain "Converting module to be internal."
+find kyaml/internal/forked/github.com/go-yaml/yaml -name "*.go" -type f | xargs sed -i '' s+"gopkg.in/yaml.v3"+"sigs.k8s.io/kustomize/kyaml/internal/forked/github.com/go-yaml/yaml"+g
+rm kyaml/internal/forked/github.com/go-yaml/yaml/go.mod
+git commit --all -m "Internalize forked code"
+
+explain "Cherry-picking the commits from our test fixes in Kustomize PR"
+cherry-pick https://github.com/kubernetes-sigs/kustomize $KUSTOMIZE_PR
+
+explain "SUCCEEDED."
+exit 0