From 0a97226723f589f94c4e7a66f9d0b36e0359b038 Mon Sep 17 00:00:00 2001
From: Nelson Araujo <nelsonjr@users.noreply.github.com>
Date: Sat, 28 Dec 2024 00:22:05 -0800
Subject: [PATCH 1/2] Allow restoring directories

---
 backends/cache_fs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/backends/cache_fs b/backends/cache_fs
index 6fd472b..75fbe76 100755
--- a/backends/cache_fs
+++ b/backends/cache_fs
@@ -22,7 +22,11 @@ restore_cache() {
   # shellcheck disable=2064  # actually want variable interpolated here
   trap "release_lock_folder '${from}'" SIGINT SIGTERM SIGQUIT
 
-  cp -a "$from" "$to"
+  if [ -d "$from" ]; then
+    cp -a "${from}/." "$to" # copy as folder
+  else
+    cp -a "$from" "$to"
+  fi
 
   release_lock "${from}"
 }

From c16e461df2f0f744cd9b94a9755da45ad7898d93 Mon Sep 17 00:00:00 2001
From: Nelson Araujo <nelsonjr@users.noreply.github.com>
Date: Sat, 28 Dec 2024 01:26:25 -0800
Subject: [PATCH 2/2] Allow selecting 'rsync' as copy tool

---
 backends/cache_fs   | 13 +++++++++++--
 hooks/post-checkout | 10 ++++++++--
 lib/plugin.bash     | 13 +++++++++++++
 plugin.yml          |  5 +++++
 4 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/backends/cache_fs b/backends/cache_fs
index 75fbe76..363b7d2 100755
--- a/backends/cache_fs
+++ b/backends/cache_fs
@@ -17,15 +17,24 @@ DIR="$(cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd)"
 restore_cache() {
   local from="${CACHE_FOLDER}/$1"
   local to="$2"
+  local fs_copy_tool="$3"
 
   wait_and_lock "${from}"
   # shellcheck disable=2064  # actually want variable interpolated here
   trap "release_lock_folder '${from}'" SIGINT SIGTERM SIGQUIT
 
   if [ -d "$from" ]; then
-    cp -a "${from}/." "$to" # copy as folder
+    if [ "$fs_copy_tool" = "rsync" ]; then
+      rsync -a --delete "${from}/." "$to" # copy as folder
+    else
+      cp -a "${from}/." "$to" # copy as folder
+    fi
   else
-    cp -a "$from" "$to"
+    if [ "$fs_copy_tool" = "rsync" ]; then
+      rsync -a --delete "$from" "$to"
+    else
+      cp -a "$from" "$to"
+    fi
   fi
 
   release_lock "${from}"
diff --git a/hooks/post-checkout b/hooks/post-checkout
index a98fcfb..d7b6a95 100755
--- a/hooks/post-checkout
+++ b/hooks/post-checkout
@@ -30,6 +30,12 @@ if ! validate_compression "${COMPRESS}"; then
   exit 1
 fi
 
+FS_COPY_TOOL=$(plugin_read_config FS_COPY_TOOL 'cp')
+if ! validate_fs_copy_tool "${FS_COPY_TOOL}"; then
+  echo "+++ 🚨 Invalid value for fs_copy_tool option"
+  exit 1
+fi
+
 build_key "${MAX_LEVEL}" "${RESTORE_PATH}" >/dev/null # to validate the level
 
 SORTED_LEVELS=(file step branch pipeline all)
@@ -45,10 +51,10 @@ for CURRENT_LEVEL in "${SORTED_LEVELS[@]}"; do
 
     if compression_active; then
       TEMP_PATH=$(mktemp)
-      backend_exec get "${KEY}" "${TEMP_PATH}"
+      backend_exec get "${KEY}" "${TEMP_PATH}" "cp"
       uncompress "${TEMP_PATH}" "${RESTORE_PATH}"
     else
-      backend_exec get "${KEY}" "${RESTORE_PATH}"
+      backend_exec get "${KEY}" "${RESTORE_PATH}" "${FS_COPY_TOOL}"
     fi
 
     exit 0
diff --git a/lib/plugin.bash b/lib/plugin.bash
index 70676c6..43af7f1 100644
--- a/lib/plugin.bash
+++ b/lib/plugin.bash
@@ -59,4 +59,17 @@ function plugin_read_config() {
   local var="BUILDKITE_PLUGIN_${PLUGIN_PREFIX}_${1}"
   local default="${2:-}"
   echo "${!var:-$default}"
+}
+
+function validate_fs_copy_tool() {
+  local FS_COPY_TOOL="$1"
+
+  VALID_FS_COPY_TOOL=(cp rsync)
+  for VALID in "${VALID_FS_COPY_TOOL[@]}"; do
+    if [ "${FS_COPY_TOOL}" = "${VALID}" ]; then
+      return 0
+    fi
+  done
+
+  return 1
 }
\ No newline at end of file
diff --git a/plugin.yml b/plugin.yml
index 500b494..67943ce 100644
--- a/plugin.yml
+++ b/plugin.yml
@@ -35,6 +35,11 @@ configuration:
         - type: array
           items:
             $ref: '#/$defs/valid_levels'
+    fs_copy_tool:
+      type: string
+      enum:
+        - cp
+        - rsync
   additionalProperties: false
   anyOf:
     - required: [ path, save ]