configuration: SCL hacks

Its now configurable what software collections will be enabled for
pg_upgrade run, in case it is needed (new 'scls' option).
Similarly, pg_upgrade needs to be told to send
unix_socket_directories instead of unix_socket_directory to
PostgreSQL server built for RHEL.

* etc/postgresql-setup/upgrade/postgresql.conf: Add configuration
examples for new options.
* postgresql-setup.in (parse_upgrade_setup): Parse 'scls' and
'redhat_sockets_hack' options.
(upgrade): Adjust the environment of 'su - postgres' call to
pg_upgrade, optionally.

3 files changed, 49 insertions, 2 deletions

diff --git a/NEWS b/NEWS
index adbfef8..b516bae 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,9 @@ New in 3.0 version
 * Legacy scripts are now generated from single template file, also are
   simplified a bit.
 
+* There are now options (by upgrade configuration file) how to upgrade from an
+  PG stack running in SCL (Software Collections)
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 New in 2.0 version
diff --git a/etc/postgresql-setup/upgrade/postgresql.conf b/etc/postgresql-setup/upgrade/postgresql.conf
index db58470..49d58b5 100644
--- a/etc/postgresql-setup/upgrade/postgresql.conf
+++ b/etc/postgresql-setup/upgrade/postgresql.conf
@@ -16,3 +16,11 @@ engine          /usr/bin
 
 # Just to feed ./postgresql-setup --upgrade-ids help output
 description     "In-place upgrade from Fedora 19 (PostgreSQL 9.2)"
+
+# What software collections must be enabled for successful upgrade.
+scls            "postgresql92"
+
+# Red Hat back-patches unix_socket_directories into major versions 9.2+, which
+# is different from upstream (9.3+).  You may need to let pg_upgrade know that
+# it works against server 9.2 built by Red Hat.
+redhat_sockets_hack  yes
diff --git a/postgresql-setup.in b/postgresql-setup.in
index dadb615..fc377ff 100644
--- a/postgresql-setup.in
+++ b/postgresql-setup.in
@@ -148,9 +148,11 @@ parse_upgrade_setup()
 
     local upgrade_confdir="@sysconfdir@/@NAME_BINARYBASE@-setup/upgrade"
 
+    debug "using 'upgrade' confdir $upgrade_confdir"
     test -d "$upgrade_confdir" || die "can't read confdir $upgrade_confdir"
 
-    local my_vars="id comment data_default engine description major"
+    local my_vars="id comment data_default engine description major scls \
+        redhat_sockets_hack"
     while read conffile
     do
         read_config_file "$conffile" "$my_vars"
@@ -162,6 +164,26 @@ parse_upgrade_setup()
             debug "reading config $conffile"
             for i in $my_vars; do
                 set_var "upgradefrom_$i" "\$__pg_conf_$i"
+
+                local cm="config file '$conffile'"
+                # 'scls' and 'redhat_sockets_hack' are used to adjust
+                # environment and could be bash-injected.
+                case "$i" in
+                scls)
+                    test -z "$upgrade_from_scls" \
+                        || [[ $upgrade_from_scls =~ ^[-a-zA-Z0-9_\ ]+$ ]] \
+                        || die "$cm: bad '$i' value '$upgrade_from_scls'"
+                    ;;
+                redhat_sockets_hack)
+                    case "$upgradefrom_redhat_sockets_hack" in
+                    yes|no|'')
+                        ;;
+                    *)
+                        die "$cm: bad '$i' value"
+                        ;;
+                    esac
+                    ;;
+                esac
             done
             return 0
         fi
@@ -313,10 +335,24 @@ upgrade()
 
     info $"Upgrading database."
 
+    scls_upgrade_hacks=
+    test -n "$upgradefrom_scls" && {
+        debug "scls [$upgradefrom_scls] will be enabled"
+        scls_upgrade_hacks="source scl_source enable $upgradefrom_scls ;"
+    }
+
+    test -n "$upgradefrom_redhat_sockets_hack" && {
+        debug "upgrading from redhat server"
+        socket_hacks="export REDHAT_PGUPGRADE_FROM_RHEL=yes ;"
+    }
+
     # Create empty new-format database
     if perform_initdb; then
         # Do the upgrade
-        $SU_POSTGRES -c "$PGENGINE/pg_upgrade \
+        $SU_POSTGRES -c "\
+                        $scls_upgrade_hacks \
+                        $socket_hacks \
+                        $PGENGINE/pg_upgrade \
                         '--old-bindir=$upgradefrom_engine' \
                         '--new-bindir=$PGENGINE' \
                         '--old-datadir=$pgdataold' \