fix(mongodb): harden backup info collection

addons/mongodb/dataprotection/backup-info-collector.sh

@@ -1,25 +1,132 @@
 # shellcheck disable=SC2148
 function get_current_time() {
-  if [ -n "$(whereis mongosh | awk '{print $2}')" ]; then
-    CLIENT="mongosh"
+  local client curr_time status
+
+  if command -v mongosh >/dev/null 2>&1; then
+    client="mongosh"
+  elif command -v mongo >/dev/null 2>&1; then
+    client="mongo"
+  else
+    printf 'backup info timestamp client unavailable rc=127\n' >&2
+    return 127
+  fi
+
+  if curr_time=$(
+    "$client" \
+      -u "$DP_DB_USER" \
+      -p "$DP_DB_PASSWORD" \
+      --port "$DP_DB_PORT" \
+      --host "$DP_DB_HOST" \
+      --authenticationDatabase admin \
+      --eval 'db.isMaster().lastWrite.lastWriteDate.getTime()/1000' \
+      --quiet
+  ); then
+    :
   else
-    CLIENT="mongo"
+    status=$?
+    printf 'backup info timestamp client failed rc=%s\n' "$status" >&2
+    return "$status"
   fi
-  curr_time=$(${CLIENT} -u ${DP_DB_USER} -p ${DP_DB_PASSWORD} --port ${DP_DB_PORT} --host ${DP_DB_HOST} --authenticationDatabase admin --eval 'db.isMaster().lastWrite.lastWriteDate.getTime()/1000' --quiet)
-  curr_time=$(date -d "@${curr_time}" -u '+%Y-%m-%dT%H:%M:%SZ')
-  echo $curr_time
+
+  if [ -z "$curr_time" ]; then
+    printf 'backup info timestamp client returned empty output rc=65\n' >&2
+    return 65
+  fi
+
+  if curr_time=$(date -d "@${curr_time}" -u '+%Y-%m-%dT%H:%M:%SZ'); then
+    :
+  else
+    status=$?
+    printf 'backup info timestamp conversion failed rc=%s\n' "$status" >&2
+    return "$status"
+  fi
+
+  if [ -z "$curr_time" ]; then
+    printf 'backup info timestamp conversion returned empty output rc=65\n' >&2
+    return 65
+  fi
+
+  printf '%s\n' "$curr_time"
 }
 
 function stat_and_save_backup_info() {
+  local start_time stop_time stat_output status total_size tmp_file
+
   export PATH="$PATH:$DP_DATASAFED_BIN_PATH"
   export DATASAFED_BACKEND_BASE_PATH="$DP_BACKUP_BASE_PATH"
-  START_TIME=$1
-  STOP_TIME=$2
-  if [ -z $STOP_TIME ]; then
-    STOP_TIME=$(get_current_time)
+
+  start_time=${1:-}
+  stop_time=${2:-}
+  if [ -z "$stop_time" ]; then
+    if stop_time=$(get_current_time); then
+      :
+    else
+      status=$?
+      printf 'backup info stop timestamp failed rc=%s\n' "$status" >&2
+      return "$status"
+    fi
+  fi
+
+  if stat_output=$(datasafed stat /); then
+    :
+  else
+    status=$?
+    printf 'backup info datasafed stat failed rc=%s\n' "$status" >&2
+    return "$status"
+  fi
+
+  if total_size=$(
+    printf '%s\n' "$stat_output" |
+      awk '
+        $1 == "TotalSize:" {
+          count++
+          if (NF == 2 && $2 ~ /^[0-9]+$/) {
+            valid++
+            value = $2
+          }
+        }
+        END {
+          if (count == 1 && valid == 1) {
+            print value
+            exit 0
+          }
+          exit 65
+        }
+      '
+  ); then
+    :
+  else
+    printf 'backup info TotalSize validation failed rc=65\n' >&2
+    return 65
+  fi
+
+  if tmp_file=$(mktemp "${DP_BACKUP_INFO_FILE}.tmp.XXXXXX"); then
+    :
+  else
+    status=$?
+    printf 'backup info temporary file creation failed rc=%s\n' "$status" >&2
+    return "$status"
   fi
-  TOTAL_SIZE=$(datasafed stat / | grep TotalSize | awk '{print $2}')
-  echo "{\"totalSize\":\"$TOTAL_SIZE\",\"timeRange\":{\"start\":\"${START_TIME}\",\"end\":\"${STOP_TIME}\"}}" >"${DP_BACKUP_INFO_FILE}"
+
+  if printf '{"totalSize":"%s","timeRange":{"start":"%s","end":"%s"}}\n' \
+    "$total_size" "$start_time" "$stop_time" >"$tmp_file"; then
+    :
+  else
+    status=$?
+    rm -f "$tmp_file" || :
+    printf 'backup info temporary file write failed rc=%s\n' "$status" >&2
+    return "$status"
+  fi
+
+  if mv "$tmp_file" "$DP_BACKUP_INFO_FILE"; then
+    return 0
+  else
+    status=$?
+  fi
+
+  rm -f "$tmp_file" || :
+  printf 'backup info publication failed rc=%s\n' "$status" >&2
+  return "$status"
 }
 
 # if the script exits with a non-zero exit code, touch a file to indicate that the backup failed,

addons/mongodb/dataprotection/datafile-backup.sh

@@ -1,9 +1,16 @@
+# shellcheck shell=bash
 set -o pipefail
 export PATH="$PATH:$DP_DATASAFED_BIN_PATH"
 export DATASAFED_BACKEND_BASE_PATH="$DP_BACKUP_BASE_PATH"
 trap handle_exit EXIT
-cd ${DATA_DIR}
-START_TIME=$(get_current_time)
+# shellcheck disable=SC2164
+cd "$DATA_DIR"
+if START_TIME=$(get_current_time); then
+  :
+else
+  status=$?
+  exit "$status"
+fi
 # TODO: flush data and locked write, otherwise data maybe inconsistent
 # NOTE: if files changed during taring, the exit code will be 1 when it ends.
 tar -cvf - ./ | datasafed push -z zstd-fastest - "${DP_BACKUP_NAME}.tar.zst"