replaced redis err check w/ verification of success string piped to log

root/scripts/backup.sh

@@ -144,6 +144,15 @@ function checkExist {
             # not found
             return 1
         fi
+    elif [ "$1" = "fs" ]; then
+        # find file > 0 bytes
+        if [ -s "$2" ]; then
+            # found
+            return 0
+        else
+            # not found
+            return 1
+        fi
     elif [ "$1" = "fd" ]; then
         # find directory
         if [ -d "$2" ]; then
@@ -556,22 +565,24 @@ fi
 ### Dump SQL
 echo -e "${op}${stamp} Dumping mailcow SQL database...${normal}" >> "$logFile"
 docker-compose exec mysql-mailcow mysqldump --default-character-set=utf8mb4 -u${DBUSER} -p${DBPASS} ${DBNAME} > "$sqlDumpDir/$sqlDumpFile" 2>> "$logFile"
-checkResult=$(docker-compose exec -T mysql-mailcow echo $?)
-# verify sql dump was successful
-if [ "$checkResult" = 0 ]; then
-    echo -e "${ok}${stamp} -- [SUCCESS] SQL successfully dumped --${normal}" \
-        >> "$logFile"
+## error checking sqldump within the container in a cron-friendly manner is a
+## nightmare, so let's just see if a non-empty file with the expected name was
+## created
+checkExist fs "$sqlDumpDir/$sqlDumpFile"
+    checkResult="$?"
+    if [ "$checkResult" = "0" ]; then
+        echo -e "${ok}${stamp} -- [SUCCESS] SQL successfully dumped --" \
+            "${normal}" >> "$logFile"
     else
         exitError+=("${stamp}_201")
     fi
 
-
 ### Save redis state
 echo -e "${op}${stamp} Saving redis state information...${normal}" >> "$logFile"
 docker-compose exec redis-mailcow redis-cli save >> "$logFile" 2>&1
-checkResult=$(docker-compose exec -T redis-mailcow echo "$?")
-# Verify save was successful
-if [ "$checkResult" = 0 ]; then
+## redis outputs a simple 'OK' if the export succeeded, so check the log file
+## for a line just written that says that specifically
+if [ $(tail -1 "$logFile") = "OK" ];
     echo -e "${ok}${stamp} -- [SUCCESS] redis state saved --${normal}" \
         >> "$logFile"
     else