From 43a122fe18abec5d7607e9659a890780930bb1ce Mon Sep 17 00:00:00 2001
From: Casper <casperklein@users.noreply.github.com>
Date: Sun, 27 Aug 2023 23:40:24 +0200
Subject: [PATCH] scripts: add wrapper to update Postfix configuration safely
 (follow up) (#3503)

---
 target/scripts/helpers/postfix.sh | 26 +++++++++++++++-----------
 target/scripts/helpers/utils.sh   |  1 +
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/target/scripts/helpers/postfix.sh b/target/scripts/helpers/postfix.sh
index b376dce9..5fa4fa83 100644
--- a/target/scripts/helpers/postfix.sh
+++ b/target/scripts/helpers/postfix.sh
@@ -92,39 +92,43 @@ function _vhost_ldap_support() {
 # /etc/aliases is handled by `alias.sh` and uses `postalias` to update the Postfix alias database. No need for `postmap`.
 # http://www.postfix.org/postalias.1.html
 
-# Add an key with an value to Postfix's main configuration file
+# Add a key with a value to Postfix's main configuration file
 # or update an existing key. An already existing key can be updated
 # by either appending to the existing value (default) or by prepending.
 #
 # @param ${1} = key name in Postfix's main configuration file
 # @param ${2} = new value (appended or prepended)
-# @param ${3} = "append" (default) or "prepend" [OPTIONAL]
+# @param ${3} = action "append" (default) or "prepend" [OPTIONAL]
 function _add_to_or_update_postfix_main() {
   local KEY=${1:?Key name is required}
   local NEW_VALUE=${2:?New value is required}
   local ACTION=${3:-append}
+  local CURRENT_VALUE
 
-  # If entry does not exist, add it - otherwise update with ACTION:
-  if ! grep -q -E "^${KEY}" /etc/postfix/main.cf; then
+  # Get current value from /etc/postfix/main.cf
+  _adjust_mtime_for_postfix_maincf
+  CURRENT_VALUE=$(postconf -h "${KEY}" 2>/dev/null)
+
+  # If key does not exist or value is empty, add it - otherwise update with ACTION:
+  if [[ -z ${CURRENT_VALUE} ]]; then
     postconf "${KEY} = ${NEW_VALUE}"
   else
-    KEY=$(_escape_for_sed "${KEY}")
-    NEW_VALUE=$(_escape_for_sed "${NEW_VALUE}")
-    local SED_STRING
+    # If $NEW_VALUE is already present --> nothing to do, skip.
+    if [[ " ${CURRENT_VALUE} " == *" ${NEW_VALUE} "* ]]; then
+      return 0
+    fi
 
     case "${ACTION}" in
       ('append')
-        SED_STRING="/${NEW_VALUE}/! s|^(${KEY} *=.*)|\1 ${NEW_VALUE}|g"
+        postconf "${KEY} = ${CURRENT_VALUE} ${NEW_VALUE}"
         ;;
       ('prepend')
-        SED_STRING="/${NEW_VALUE}/! s|^(${KEY}) *= *(.*)|\1 = ${NEW_VALUE} \2|g"
+        postconf "${KEY} = ${NEW_VALUE} ${CURRENT_VALUE}"
         ;;
       (*)
         _log 'error' "Action '${3}' in _add_to_or_update_postfix_main is unknown"
         return 1
         ;;
     esac
-
-    sed -i -E "${SED_STRING}" /etc/postfix/main.cf
   fi
 }
diff --git a/target/scripts/helpers/utils.sh b/target/scripts/helpers/utils.sh
index 02d29cc9..c74fd7e8 100644
--- a/target/scripts/helpers/utils.sh
+++ b/target/scripts/helpers/utils.sh
@@ -4,6 +4,7 @@ function _escape() {
   echo "${1//./\\.}"
 }
 
+# TODO: Not in use currently. Maybe in the future: https://github.com/docker-mailserver/docker-mailserver/pull/3484/files#r1299410851
 # Replaces a string so that it can be used inside
 # `sed` safely.
 #