overlay coreos/stage1_hooks: Hook for no split-usr for SDK

sdk_container/src/third_party/coreos-overlay/coreos/stage1_hooks/0004-no-split-usr-for-SDK-coreos-overlay.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+set -euo pipefail
+
+stage1_repo=${1}
+
+old_use_force="${stage1_repo}/profiles/coreos/targets/generic/use.force"
+new_use_force="${stage1_repo}/profiles/coreos/base/use.force"
+
+old_use_mask="${stage1_repo}/profiles/coreos/targets/generic/use.mask"
+new_use_mask="${stage1_repo}/profiles/coreos/base/use.mask"
+
+make_defaults="${stage1_repo}/profiles/coreos/targets/generic/make.defaults"
+
+grep_cmd=(
+    grep
+    --fixed-strings
+    --quiet
+    --line-regexp
+    --no-messages # swallow errors about nonexistent files
+)
+
+if ! "${grep_cmd[@]}" --regexp '-split-usr' "${old_use_force}"; then
+    # No unforcing of split-usr in old use.force, not continuing
+    exit 0
+fi
+
+if "${grep_cmd[@]}" --regexp '-split-usr' "${new_use_force}"; then
+    # split-usr already unforced in new use.mask, not continuing
+    exit 0
+fi
+
+if ! "${grep_cmd[@]}" 'split-usr' "${old_use_mask}"; then
+    # No masking of split-usr in old use.mask, not continuing
+    exit 0
+fi
+
+if "${grep_cmd[@]}" 'split-usr' "${new_use_mask}"; then
+    # split-usr already masked in new use.mask, not continuing
+    exit 0
+fi
+
+if ! grep --quiet --no-messages '^USE="[^"]*\bsymlink-usr\b' "${make_defaults}"; then
+    # symlink-usr dropped from make.defaults, not continuing
+    exit 0
+fi
+
+sed -i -e '/^-split-usr$/d' "${old_use_force}"
+printf '%s\n' '-split-usr' >>"${new_use_force}"
+sed -i -e '/^split-usr$/d' "${old_use_mask}"
+printf '%s\n' 'split-usr' >>"${new_use_mask}"
+sed -i -e 's/\(^USE="[^"]*\)\bsymlink-usr\b\(.*\)/\1\2/' "${make_defaults}"
+sed -i -e 's/\(^USE="[^"]*\)\bsymlink-usr\b\(.*\)/\1\2/' "${make_defaults}"