Enable pg_dump format option.

The format option of pg_dump enables tar and custom archive file formats in
addition to the default plain-text file containing SQL commands.

When either the tar or custom format are selected the behaviour of database=all is changed to no longer dump a single file via pg_dumpall. Instead pg_dumpall
is called once to export the "global" data (roles & tablespaces) and then
pg_dump is called once for each non-template table in the database.

To support the GZIP and GZIP_OPTS variables in backupninja and to give the
default --rsyncable gzip compression flag a chance at working on a PostgreSQL
backup, the custom output is forced to not use compression. Instead compression
is done via a pipe to gzip. Hopefully this benefits rsync and rdiff-backup
style backups for reduced backup and storage costs that outweigh the
restoration ones.

2 files changed, 119 insertions, 11 deletions

diff --git a/handlers/pgsql.helper.in b/handlers/pgsql.helper.in
index ff1cfd4..82e6b48 100644
--- a/handlers/pgsql.helper.in
+++ b/handlers/pgsql.helper.in
@@ -67,6 +67,21 @@ pgsql_wizard() {
       pgsql_compress="compress = no"
    fi
 
+   # pg_dump format, defaults to plain, custom is recommended by PostgreSQL
+   menuBox "$pgsql_title" "Choose a pg_dump format:" \
+      plain "Default plain-text sql script, use with psql." \
+      tar "More flexible than the plain, use with pg_restore." \
+      custom "The most flexible format, use with pg_restore."
+   if [ $? = 0 ]; then
+      result="$REPLY"
+      case "$result" in
+         "tar") pgsql_format="format = tar";;
+         "custom") pgsql_format="format = custom";;
+         *) pgsql_format = "format = plain";;
+      esac
+   fi
+         
+
    # write config file
    get_next_filename $configdirectory/20.pgsql
    cat >> $next_filename <<EOF
@@ -97,7 +112,22 @@ $pgsql_databases
 # if yes, compress the pg_dump/pg_dumpall output.
 $pgsql_compress
 
+# format = < plain | tar | custom > (default = plain)
+# plain -  Output a plain-text SQL script file with the extension .sql.
+#          When dumping all databases, a single file is created via pg_dumpall.
+# tar -    Output a tar archive suitable for input into pg_restore. More 
+#          flexible than plain and can be manipulated by standard Unix tools 
+#          such as tar. Creates a globals.sql file and an archive per database.
+# custom - Output a custom PostgreSQL pg_restore archive. This is the most
+#          flexible format allowing selective import and reordering of database
+#          objects at the time the database is restored via pg_restore. This
+#          option creates a globals.sql file containing the cluster role and
+#          other information dumped by pg_dumpall -g and a pg_restore file
+#          per selected database. See the pg_dump and pg_restore man pages.
+$pgsql_format
+
 ### You can also set the following variables in backupninja.conf:
+# PSQL: psql path (default: /usr/bin/psql)
 # PGSQLDUMP: pg_dump path (default: /usr/bin/pg_dump)
 # PGSQLDUMPALL: pg_dumpall path (default: /usr/bin/pg_dumpall)
 # PGSQLUSER: user running PostgreSQL (default: postgres)
diff --git a/handlers/pgsql.in b/handlers/pgsql.in
index 0b7badf..0564f5a 100644
--- a/handlers/pgsql.in
+++ b/handlers/pgsql.in
@@ -8,6 +8,8 @@ getconf backupdir /var/backups/postgres
 getconf databases all
 getconf compress yes
 getconf vsname
+# format maps to pg_dump --format= option, old/default was plain
+getconf format plain
 
 localhost=`hostname`
 
@@ -35,17 +37,31 @@ fi
 # Make sure that the system to backup has the needed executables
 if [ $usevserver = yes ]; then
    debug "Examining vserver '$vsname'."
-   if [ "$databases" == "all" ]; then
+   if [ "$databases" == "all" ] && [ "$format" = "plain" ]; then
       [ -x "$vroot`$VSERVER $vsname exec which $PGSQLDUMPALL`" ] || \
          fatal "Can't find $PGSQLDUMPALL in vserver $vsname."
+   elif [ "$format" != "plain" ]; then
+      [ -x "$vroot`$VSERVER $vsname exec which $PGSQLDUMPALL`" ] || \
+         fatal "Can't find $PGSQLDUMPALL in vserver $vsname."
+      [ -x "$vroot`$VSERVER $vsname exec which $PGSQLDUMP`" ] || \
+         fatal "Can't find $PGSQLDUMP in vserver $vsname."
+      [ -x "$vroot`$VSERVER $vsname exec which $PSQL`" ] || \
+         fatal "Can't find $PSQL in vserver $vsname."
    else
       [ -x "$vroot`$VSERVER $vsname exec which $PGSQLDUMP`" ] || \
          fatal "Can't find $PGSQLDUMP in vserver $vsname."
    fi
 else
-   if [ "$databases" == "all" ]; then
+   if [ "$databases" == "all" ] && [ "$format" = "plain" ]; then
+      [ -x "`which $PGSQLDUMPALL`" ] || \
+         fatal "Can't find $PGSQLDUMPALL."
+   elif [ "$format" != "plain" ]; then
       [ -x "`which $PGSQLDUMPALL`" ] || \
          fatal "Can't find $PGSQLDUMPALL."
+      [ -x "`which $PGSQLDUMP`" ] || \
+         fatal "Can't find $PGSQLDUMP."
+      [ -x "`which $PSQL`" ] || \
+         fatal "Can't find $PSQL."
    else
       [ -x "`which $PGSQLDUMP`" ] || \
          fatal "Can't find $PGSQLDUMP."
@@ -71,6 +87,30 @@ chown $pguid $vroot$backupdir
 debug "chmod 700 $vroot$backupdir"
 chmod 700 $vroot$backupdir
 
+
+# If we are using the custom (best) or tar pg_dump format, and
+# dumping "all" databases, we will substitute "all" for a list
+# of all non-template databases to avoid the use of pg_dumpall.
+dumpglobals="no"
+if [ "$databases" = "all" ] && [ "$format" != "plain" ]; then
+   cmdprefix=""
+   if [ "$usevserver" = "yes" ]; then
+      	cmdprefix="$VSERVER $vsname exec "
+   fi
+   execstr="${cmdprefix} su - $PGSQLUSER -c 'psql -AtU $PGSQLUSER -c \"SELECT datname FROM pg_database WHERE NOT datistemplate\"'"
+   debug execstr
+   dblist=""
+   for db in $(eval $execstr 2>&1); do
+      dblist="$dblist $db"
+   done
+   if [ "$dblist" != "" ]; then
+      databases="$dblist"
+   fi
+   # Dump globals (pg_dumpall -g) for roles and tablespaces
+   dumpglobals="yes"
+fi
+
+
 # if $databases = all, use pg_dumpall
 if [ "$databases" == "all" ]; then
    if [ $usevserver = yes ]; then
@@ -101,20 +141,58 @@ if [ "$databases" == "all" ]; then
 
 # else use pg_dump on each specified database
 else
-   for db in $databases; do
+   # If we're not doing plain format, database=all may now be database=list
+   # so we track the database=all selection in dumpglobals which tells us
+   # to also dump the roles and tablespaces via pg_dumpall -g
+   if [ "$dumpglobals" = "yes" ]; then
+      globalscmd=""
+      if [ "$compress" == "yes" ]; then
+         globalscmd="set -o pipefail ; $PGSQLDUMPALL -g | $GZIP $GZIP_OPTS > '$backupdir/globals.sql.gz'"
+      else
+         globalscmd="$PGSQLDUMPALL -g > '$backupdir/globals.sql'"
+      fi
       if [ $usevserver = yes ]; then
-         if [ "$compress" == "yes" ]; then
-            execstr="$VSERVER $vsname exec su - $PGSQLUSER -c \"set -o pipefail ; $PGSQLDUMP $db | $GZIP $GZIP_OPTS > '$backupdir/${db}.sql.gz'\""
-         else
-            execstr="$VSERVER $vsname exec su - $PGSQLUSER -c \"$PGSQLDUMP $db | > '$backupdir/${db}.sql'\""
-         fi
+         execstr="$VSERVER $vsname exec su - $PGSQLUSER -c \"$globalscmd\""
       else
-         if [ "$compress" == "yes" ]; then
-            execstr="su - $PGSQLUSER -c \"set -o pipefail ; $PGSQLDUMP $db | $GZIP $GZIP_OPTS > '$backupdir/${db}.sql.gz'\""
+         execstr="su - $PGSQLUSER -c \"$globalscmd\""
+      fi
+      debug "$execstr"
+      if [ ! $test ]; then
+         output=`eval $execstr 2>&1`
+         code=$?
+         if [ "$code" == "0" ]; then
+            debug $output
+            info "Successfully finished pgsql globals (roles and tablespaces) dump"
          else
-            execstr="su - $PGSQLUSER -c \"$PGSQLDUMP $db > '$backupdir/${db}.sql'\""
+            warning $output
+            warning "Failed to dump pgsql globals (roles and tablespaces)"
          fi
       fi
+   fi
+   for db in $databases; do
+      dumpext=".sql"
+      if [ "$format" != "plain" ]; then
+         dumpext="pg_dump"
+      fi
+      # To better support the backupninja global GZIP and rsync-friendly GZIP_OPTS
+      # the custom archive format is told to disable compression. The plain format
+      # is uncompressed by default and the tar format doesn't support pg_dump compression.
+      disablecustomcompress=""
+      if [ "$format" = "custom" ]; then
+         disablecustomcompress="--compress=0"
+      fi
+      dumpcmd=""
+      globalscmd=""
+      if [ "$compress" == "yes" ]; then
+         dumpcmd="set -o pipefail ; $PGSQLDUMP --format=$format ${disablecustomcompress} $db | $GZIP $GZIP_OPTS > '$backupdir/${db}.${dumpext}.gz'"
+      else
+         dumpcmd="$PGSQLDUMP --format=$format ${disablecustomcompress} $db | > '$backupdir/${db}.${dumpext}'"
+      fi
+      if [ $usevserver = yes ]; then
+         execstr="$VSERVER $vsname exec su - $PGSQLUSER -c \"$dumpcmd\""
+      else
+         execstr="su - $PGSQLUSER -c \"$dumpcmd\""
+      fi
       debug "$execstr"
       if [ ! $test ]; then
          output=`eval $execstr 2>&1`