Subject: [PATCH v3] Allow wildcard (%) in extension upgrade paths

From: Sandro Santilli <[email-masked]>
Date: Wed, 14 Sep 2022 11:10:10 +0200

A wildcard character "%" will be accepted in the
"source" side of the upgrade script and be considered
usable to upgrade any version to the "target" side.

Using wildcards needs to be explicitly requested by
extensions via a "wildcard_upgrades" setting in their
control file.

Includes regression test and documentation.
---
 doc/src/sgml/extend.sgml                      | 14 +++++
 src/backend/commands/extension.c              | 58 +++++++++++++++++--
 src/test/modules/test_extensions/Makefile     |  7 ++-
 .../expected/test_extensions.out              | 15 +++++
 .../test_extensions/sql/test_extensions.sql   |  9 +++
 .../test_ext_wildcard1--%--2.0.sql            |  6 ++
 .../test_ext_wildcard1--1.0.sql               |  6 ++
 .../test_ext_wildcard1.control                |  4 ++
 8 files changed, 110 insertions(+), 9 deletions(-)
 create mode 100644 src/test/modules/test_extensions/test_ext_wildcard1--%--2.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_wildcard1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_wildcard1.control

diff --git a/doc/src/sgml/extend.sgml b/doc/src/sgml/extend.sgml
index 218940ee5c..3d4003eaef 100644
--- a/doc/src/sgml/extend.sgml
+++ b/doc/src/sgml/extend.sgml
@@ -822,6 +822,20 @@ RETURNS anycompatible AS ...
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry id="extend-extensions-wildcard-upgrade">
+      <term><varname>wildcard_upgrades</varname> (<type>boolean</type>)</term>
+      <listitem>
+       <para>
+        This parameter, if set to <literal>true</literal> (which is not the
+        default), allows <command>ALTER EXTENSION</command> to consider
+        a wildcard character <literal>%</literal> as matching any version of
+        the extension. Such wildcard match will only be used when no
+        perfect match is found for a version.
+       </para>
+      </listitem>
+     </varlistentry>
+
     </variablelist>
 
     <para>
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 0eabe18335..207b4649f2 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -88,6 +88,7 @@ typedef struct ExtensionControlFile
 	bool		relocatable;	/* is ALTER EXTENSION SET SCHEMA supported? */
 	bool		superuser;		/* must be superuser to install? */
 	bool		trusted;		/* allow becoming superuser on the fly? */
+	bool		wildcard_upgrades;  /* allow using wildcards in upgrade scripts */
 	int			encoding;		/* encoding of the script file, or -1 */
 	List	   *requires;		/* names of prerequisite extensions */
 	List	   *no_relocate;	/* names of prerequisite extensions that
@@ -132,6 +133,7 @@ static void ApplyExtensionUpdates(Oid extensionOid,
 								  bool cascade,
 								  bool is_create);
 static char *read_whole_file(const char *filename, int *length);
+static bool file_exists(const char *name);

 /*
@@ -584,6 +586,14 @@ parse_extension_control_file(ExtensionControlFile *control,
 						 errmsg("parameter \"%s\" requires a Boolean value",
 								item->name)));
 		}
+		else if (strcmp(item->name, "wildcard_upgrades") == 0)
+		{
+			if (!parse_bool(item->value, &control->wildcard_upgrades))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("parameter \"%s\" requires a Boolean value",
+								item->name)));
+		}
 		else if (strcmp(item->name, "encoding") == 0)
 		{
 			control->encoding = pg_valid_server_encoding(item->value);
@@ -656,6 +666,7 @@ read_extension_control_file(const char *extname)
 	control->relocatable = false;
 	control->superuser = true;
 	control->trusted = false;
+	control->wildcard_upgrades = false;
 	control->encoding = -1;
 
 	/*
@@ -913,7 +924,15 @@ execute_extension_script(Oid extensionOid, ExtensionControlFile *control,
 	if (from_version == NULL)
 		elog(DEBUG1, "executing extension script for \"%s\" version '%s'", control->name, version);
 	else
+	{
+		if ( control->wildcard_upgrades && ! file_exists(filename) )
+		{
+			elog(DEBUG1, "extension upgrade script \"%s\" does not exist, will try wildcard", filename);
+			/* if filename does not exist, try wildcard */
+			filename = get_extension_script_filename(control, "%", version);
+		}
 		elog(DEBUG1, "executing extension script for \"%s\" update from version '%s' to '%s'", control->name, from_version, version);
+	}
 
 	/*
 	 * If installing a trusted extension on behalf of a non-superuser, become
@@ -1259,13 +1278,23 @@ identify_update_path(ExtensionControlFile *control,
 	/* Find shortest path */
 	result = find_update_path(evi_list, evi_start, evi_target, false, false);
 
-	if (result == NIL)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("extension \"%s\" has no update path from version \"%s\" to version \"%s\"",
-						control->name, oldVersion, newVersion)));
+	if (result != NIL)
+		return result;
 
-	return result;
+	/* Find wildcard path, if allowed by control file */
+	if ( control->wildcard_upgrades )
+	{
+		evi_start = get_ext_ver_info("%", &evi_list);
+		result = find_update_path(evi_list, evi_start, evi_target, false, false);
+
+		if (result != NIL)
+			return result;
+	}
+
+	ereport(ERROR,
+			(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+			 errmsg("extension \"%s\" has no update path from version \"%s\" to version \"%s\"",
+					control->name, oldVersion, newVersion)));
 }
 
 /*
@@ -3470,3 +3499,20 @@ read_whole_file(const char *filename, int *length)
 	buf[*length] = '\0';
 	return buf;
 }
+
+static bool
+file_exists(const char *name)
+{
+	struct stat st;
+
+	Assert(name != NULL);
+
+	if (stat(name, &st) == 0)
+		return !S_ISDIR(st.st_mode);
+	else if (!(errno == ENOENT || errno == ENOTDIR || errno == EACCES))
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not access file \"%s\": %m", name)));
+
+	return false;
+}
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
index 70fc0c8e66..5a8205fd5d 100644
--- a/src/test/modules/test_extensions/Makefile
+++ b/src/test/modules/test_extensions/Makefile
@@ -7,8 +7,8 @@ EXTENSION = test_ext1 test_ext2 test_ext3 test_ext4 test_ext5 test_ext6 \
             test_ext7 test_ext8 test_ext_cine test_ext_cor \
             test_ext_cyclic1 test_ext_cyclic2 \
             test_ext_evttrig \
-            test_ext_req_schema1 test_ext_req_schema2 test_ext_req_schema3
-
+            test_ext_req_schema1 test_ext_req_schema2 test_ext_req_schema3 \
+            test_ext_wildcard1
 DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
        test_ext4--1.0.sql test_ext5--1.0.sql test_ext6--1.0.sql \
        test_ext7--1.0.sql test_ext7--1.0--2.0.sql test_ext8--1.0.sql \
@@ -18,7 +18,8 @@ DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
        test_ext_evttrig--1.0.sql test_ext_evttrig--1.0--2.0.sql \
        test_ext_req_schema1--1.0.sql \
        test_ext_req_schema2--1.0.sql \
-       test_ext_req_schema3--1.0.sql
+       test_ext_req_schema3--1.0.sql \
+       test_ext_wildcard1--1.0.sql test_ext_wildcard1--%--2.0.sql
 
 REGRESS = test_extensions test_extdepend
 
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
index a31775a260..0d4d8b4b70 100644
--- a/src/test/modules/test_extensions/expected/test_extensions.out
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -389,3 +389,18 @@ SELECT test_s_dep.dep_req2();
 
 DROP EXTENSION test_ext_req_schema1 CASCADE;
 NOTICE:  drop cascades to extension test_ext_req_schema2
+CREATE EXTENSION test_ext_wildcard1;
+SELECT ext_wildcard1_version();
+ ext_wildcard1_version 
+-----------------------
+ 1.0
+(1 row)
+
+ALTER EXTENSION test_ext_wildcard1 UPDATE TO '2.0';
+SELECT ext_wildcard1_version();
+ ext_wildcard1_version 
+-----------------------
+ 2.0
+(1 row)
+
+DROP EXTENSION test_ext_wildcard1;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
index f4947e7da6..3c40710fc1 100644
--- a/src/test/modules/test_extensions/sql/test_extensions.sql
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -232,3 +232,12 @@ ALTER EXTENSION test_ext_req_schema1 SET SCHEMA test_s_dep2;  -- now ok
 SELECT test_s_dep2.dep_req1();
 SELECT test_s_dep.dep_req2();
 DROP EXTENSION test_ext_req_schema1 CASCADE;
+
+--
+-- Test wildcard based upgrade paths
+--
+CREATE EXTENSION test_ext_wildcard1;
+SELECT ext_wildcard1_version();
+ALTER EXTENSION test_ext_wildcard1 UPDATE TO '2.0';
+SELECT ext_wildcard1_version();
+DROP EXTENSION test_ext_wildcard1;
diff --git a/src/test/modules/test_extensions/test_ext_wildcard1--%--2.0.sql b/src/test/modules/test_extensions/test_ext_wildcard1--%--2.0.sql
new file mode 100644
index 0000000000..75154e5c55
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_wildcard1--%--2.0.sql
@@ -0,0 +1,6 @@
+/* src/test/modules/test_extensions/test_ext_wildcard1--%--2.0.sql */
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION test_ext_wildcard1 UPDATE TO '2.0'" to load this file. \quit
+
+CREATE OR REPLACE FUNCTION ext_wildcard1_version() returns TEXT
+AS 'SELECT 2.0' LANGUAGE 'sql';
diff --git a/src/test/modules/test_extensions/test_ext_wildcard1--1.0.sql b/src/test/modules/test_extensions/test_ext_wildcard1--1.0.sql
new file mode 100644
index 0000000000..a69e791fda
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_wildcard1--1.0.sql
@@ -0,0 +1,6 @@
+/* src/test/modules/test_extensions/test_ext_wildcard1--1.0.sql */
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "CREATE EXTENSION test_ext_wildcard1" to load this file. \quit
+
+CREATE FUNCTION ext_wildcard1_version() returns TEXT
+AS 'SELECT 1.0' LANGUAGE 'sql';
diff --git a/src/test/modules/test_extensions/test_ext_wildcard1.control b/src/test/modules/test_extensions/test_ext_wildcard1.control
new file mode 100644
index 0000000000..865e37fa88
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_wildcard1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension wildcard 1'
+default_version = '1.0'
+relocatable = true
+wildcard_upgrades = true
-- 
2.34.1

--twb4kgisshvw5z4p--