on snapshot mode it can fallback for single database to normal pg_dump of origin

plugins/localdump/pgsql.sh

@@ -15,6 +15,7 @@
 # 2023-09-20         v1.4  FIX could not change directory to "/root": Permission denied
 # 2024-10-02  ah     v1.5  rename backup and restore function
 # 2024-12-13  ah     v1.6  backup uses a snapshot db
+# 2024-12-16  ah     v1.7  on snapshot mode it can fallback for single database to normal pg_dump of origin
 # ================================================================================
 
 if [ -z "$BACKUP_TARGETDIR" ]; then
@@ -43,21 +44,10 @@ function pgsql.backup(){
   local OUTFILE
   local snapshotprefix="snapshot_"
   local bUseSnapshot
+  local bUseSnapshot4DB
 
   typeset -i bUseSnapshot=0
 
-  # Detect a readonly or writeable postgres host.
-  TESTDB="imlbackup_createtest"
-  su ${PGUSER} -c "dropdb ${TESTDB}" >/dev/null 2>&1
-  if su ${PGUSER} -c "psql ${BACKUP_PARAMS} -c \"CREATE DATABASE ${TESTDB};\"" >/dev/null 2>&1
-  then
-    bUseSnapshot=1
-    su ${PGUSER} -c "dropdb ${TESTDB}"
-    echo "INFO: enabling snapshots"
-  else
-    echo "INFO: create database failed for snapshots - dumping databases directly"
-  fi
-
   create_targetdir
 
   # ----- change owner of directory because of su command
@@ -69,31 +59,48 @@ function pgsql.backup(){
   (
     cd /tmp
 
+    # Detect a readonly or writeable postgres host.
+    TESTDB="imlbackup_createtest"
+    su ${PGUSER} -c "dropdb ${TESTDB}" >/dev/null 2>&1
+    if su ${PGUSER} -c "psql ${BACKUP_PARAMS} -c \"CREATE DATABASE ${TESTDB};\"" >/dev/null 2>&1
+    then
+      bUseSnapshot=1
+      su ${PGUSER} -c "dropdb ${TESTDB}"
+      echo "INFO: enabling snapshots"
+    else
+      echo "INFO: create database failed for snapshots - dumping databases directly"
+    fi
+
     sSqlGetDblist="select datname from pg_database where not datistemplate and datallowconn order by datname;"
     for DATABASE in $( su ${PGUSER} -c "psql ${BACKUP_PARAMS} -At -c '$sSqlGetDblist' postgres" 2>/dev/null | grep -v "^$snapshotprefix" )
     do
       echo -n "__DB__${SERVICENAME} backup $DATABASE ... "
 
+      bUseSnapshot4DB=$bUseSnapshot
+
       SNAPSHOTDB="${DATABASE}"
-      test $bUseSnapshot -eq 1 && SNAPSHOTDB="${snapshotprefix}${DATABASE}"
+      test $bUseSnapshot4DB -eq 1 && SNAPSHOTDB="${snapshotprefix}${DATABASE}"
 
       OUTFILE="${BACKUP_TARGETDIR}/$(get_outfile ${DATABASE}).sql"
 
       myrc=0
 
       # drop snapshot db first - just in case
-      test $bUseSnapshot -eq 1 && (
+      if [ $bUseSnapshot4DB -eq 1 ]; then 
         echo -n " snapshot ... "
         su ${PGUSER} -c "dropdb ${SNAPSHOTDB}" >/dev/null 2>&1
-        su ${PGUSER} -c "psql ${BACKUP_PARAMS} -c \"CREATE DATABASE ${SNAPSHOTDB} WITH TEMPLATE ${DATABASE};\"" >/dev/null
-        fetchrc >/dev/null
-      )
+        if ! su ${PGUSER} -c "psql ${BACKUP_PARAMS} -c \"CREATE DATABASE ${SNAPSHOTDB} WITH TEMPLATE ${DATABASE};\"" >/dev/null 2>&1; then
+          echo -n " nope, using origin ... "
+          bUseSnapshot4DB=0
+          SNAPSHOTDB="${DATABASE}"
+        fi
+      fi
       if [ $myrc -eq 0 ]; then
 
         echo -n "backup ... "
         if su ${PGUSER} -c "pg_dump ${BACKUP_PARAMS} -Fp ${SNAPSHOTDB} >$OUTFILE"; then
           fetchrc >/dev/null
-          test $bUseSnapshot -eq 1 && ( 
+          test $bUseSnapshot4DB -eq 1 && ( 
             echo -n "delete snapshot ... "
             su ${PGUSER} -c "dropdb ${SNAPSHOTDB}"
           )
@@ -101,7 +108,7 @@ function pgsql.backup(){
           db._compressDumpfile "$OUTFILE"
         else
           fetchrc
-          test $bUseSnapshot -eq 1 && su ${PGUSER} -c "dropdb ${SNAPSHOTDB}"
+          test $bUseSnapshot4DB -eq 1 && su ${PGUSER} -c "dropdb ${SNAPSHOTDB}"
         fi
       else
         cecho error "ERROR!"
@@ -172,21 +179,6 @@ else
 
 fi
 
-
-# case $1 in
-#   backup)    
-#     test $SERVICEFOUND -eq 1 && pgsql.backup
-#     ;;
-#   restore)
-#     shift 1
-#     test $SERVICEFOUND -eq 1 && pgsql.restore $*
-#     ;;
-#   *)
-#     echo ERROR: wrong syntax: 
-#     echo $0 $*
-#     exit 1
-#   esac
-
 echo "__DB__$SERVICENAME INFO: $0 $* [$SERVICENAME] final returncode rc=$rc"
 
 # --------------------------------------------------------------------------------