v1-0001-PGSERVICEFILE-as-part-of-the-connection-string.patch

From f419584d2fc7766c143d304ba2f2fad98501d9ea Mon Sep 17 00:00:00 2001
From: Torsten Foertsch <tfoertsch123@gmail.com>
Date: Sat, 16 Nov 2024 20:17:20 +0100
Subject: [PATCH v1] PGSERVICEFILE as part of the connection string

Libpq interprets the PGSERVICEFILE environment variable. However,
the servicefile cannot be specified as part of the connection
string itself.

This change implements that.
---
 doc/src/sgml/libpq.sgml               | 16 ++++-
 src/interfaces/libpq/fe-connect.c     | 18 ++++-
 src/interfaces/libpq/t/006_service.pl | 97 +++++++++++++++++++++++++++
 3 files changed, 129 insertions(+), 2 deletions(-)
 create mode 100644 src/interfaces/libpq/t/006_service.pl

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index bfefb1289e..de8830bf51 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -2202,6 +2202,19 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
       </listitem>
      </varlistentry>
 
+     <varlistentry id="libpq-connect-servicefile" xreflabel="servicefile">
+      <term><literal>servicefile</literal></term>
+      <listitem>
+       <para>
+        This option specifies the name of the per-user connection service file
+        (see <xref linkend="libpq-pgservice"/>).
+        Defaults to <filename>~/.pg_service.conf</filename>, or
+        <filename>%APPDATA%\postgresql\.pg_service.conf</filename> on
+        Microsoft Windows.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="libpq-connect-target-session-attrs" xreflabel="target_session_attrs">
       <term><literal>target_session_attrs</literal></term>
       <listitem>
@@ -9337,7 +9350,8 @@ myEventProc(PGEventId evtId, void *evtInfo, void *passThrough)
    On Microsoft Windows, it is named
    <filename>%APPDATA%\postgresql\.pg_service.conf</filename> (where
    <filename>%APPDATA%</filename> refers to the Application Data subdirectory
-   in the user's profile).  A different file name can be specified by
+   in the user's profile).  A different file name can be specified using the
+   <literal>servicefile</literal> key word in a libpq connection string or by
    setting the environment variable <envar>PGSERVICEFILE</envar>.
    The system-wide file is named <filename>pg_service.conf</filename>.
    By default it is sought in the <filename>etc</filename> directory
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 51083dcfd8..117588c0e8 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -192,6 +192,9 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
 	{"service", "PGSERVICE", NULL, NULL,
 	"Database-Service", "", 20, -1},
 
+	{"servicefile", "PGSERVICEFILE", NULL, NULL,
+	"Database-Service-File", "", 64, -1},
+
 	{"user", "PGUSER", NULL, NULL,
 		"Database-User", "", 20,
 	offsetof(struct pg_conn, pguser)},
@@ -5493,6 +5496,7 @@ static int
 parseServiceInfo(PQconninfoOption *options, PQExpBuffer errorMessage)
 {
 	const char *service = conninfo_getval(options, "service");
+	const char *service_fname = conninfo_getval(options, "servicefile");
 	char		serviceFile[MAXPGPATH];
 	char	   *env;
 	bool		group_found = false;
@@ -5515,7 +5519,9 @@ parseServiceInfo(PQconninfoOption *options, PQExpBuffer errorMessage)
 	 * Try PGSERVICEFILE if specified, else try ~/.pg_service.conf (if that
 	 * exists).
 	 */
-	if ((env = getenv("PGSERVICEFILE")) != NULL)
+	if (service_fname != NULL)
+		strlcpy(serviceFile, service_fname, sizeof(serviceFile));
+	else if ((env = getenv("PGSERVICEFILE")) != NULL)
 		strlcpy(serviceFile, env, sizeof(serviceFile));
 	else
 	{
@@ -5678,6 +5684,16 @@ parseServiceFile(const char *serviceFile,
 					goto exit;
 				}
 
+				if (strcmp(key, "servicefile") == 0)
+				{
+					libpq_append_error(errorMessage,
+									   "nested servicefile specifications not supported in service file \"%s\", line %d",
+									   serviceFile,
+									   linenr);
+					result = 3;
+					goto exit;
+				}
+
 				/*
 				 * Set the parameter --- but don't override any previous
 				 * explicit setting.
diff --git a/src/interfaces/libpq/t/006_service.pl b/src/interfaces/libpq/t/006_service.pl
new file mode 100644
index 0000000000..5de84b78af
--- /dev/null
+++ b/src/interfaces/libpq/t/006_service.pl
@@ -0,0 +1,97 @@
+# Copyright (c) 2023-2024, PostgreSQL Global Development Group
+use strict;
+use warnings FATAL => 'all';
+use Config;
+use PostgreSQL::Test::Utils;
+use PostgreSQL::Test::Cluster;
+use Test::More;
+
+# This tests "service" and "servicefile"
+
+# Cluster setup which is shared for testing both load balancing methods
+my $node = PostgreSQL::Test::Cluster->new('node');
+
+# Create a data directory with initdb
+$node->init();
+
+# Start the PostgreSQL server
+$node->start();
+
+my $td = PostgreSQL::Test::Utils::tempdir;
+my $srvfile = "$td/pgsrv.conf";
+
+open my $fh, '>', $srvfile or die $!;
+print $fh "[my_srv]\n";
+print $fh +($node->connstr =~ s/ /\n/gr), "\n";
+close $fh;
+
+{
+	local $ENV{PGSERVICEFILE} = $srvfile;
+	$node->connect_ok(
+		'service=my_srv',
+		'service=my_srv',
+		sql => "SELECT 'connect1'",
+		expected_stdout => qr/connect1/);
+
+	$node->connect_ok(
+		'postgres://?service=my_srv',
+		'postgres://?service=my_srv',
+		sql => "SELECT 'connect2'",
+		expected_stdout => qr/connect2/);
+
+	local $ENV{PGSERVICE} = 'my_srv';
+	$node->connect_ok(
+		'',
+		'envvar: PGSERVICE=my_srv',
+		sql => "SELECT 'connect3'",
+		expected_stdout => qr/connect3/);
+
+	$node->connect_fails(
+		'service=non-existent-service',
+		'service=non-existent-service',
+		expected_stderr => qr/definition of service "non-existent-service" not found/);
+}
+
+{
+	$node->connect_ok(
+		q{service=my_srv servicefile='}.$srvfile.q{'},
+		'service=my_srv servicefile=...',
+		sql => "SELECT 'connect4'",
+		expected_stdout => qr/connect4/);
+
+	$node->connect_ok(
+		'postgresql:///?service=my_srv&servicefile='.($srvfile =~ s!/!%2F!gr),
+		'postgresql:///?service=my_srv&servicefile=...',
+		sql => "SELECT 'connect5'",
+		expected_stdout => qr/connect5/);
+
+	local $ENV{PGSERVICE} = 'my_srv';
+	$node->connect_ok(
+		q{servicefile='}.$srvfile.q{'},
+		'envvar: PGSERVICE=my_srv + servicefile=...',
+		sql => "SELECT 'connect6'",
+		expected_stdout => qr/connect6/);
+
+	$node->connect_ok(
+		'postgresql://?servicefile='.($srvfile =~ s!/!%2F!gr),
+		'envvar: PGSERVICE=my_srv + postgresql://?servicefile=...',
+		sql => "SELECT 'connect6'",
+		expected_stdout => qr/connect6/);
+}
+
+{
+	local $ENV{PGSERVICEFILE} = 'non-existent-file.conf';
+
+	$node->connect_fails(
+		'service=my_srv',
+		'service=... fails with wrong PGSERVICEFILE',
+		expected_stderr => qr/service file "non-existent-file\.conf" not found/);
+
+	$node->connect_ok(
+		q{service=my_srv servicefile='}.$srvfile.q{'},
+		'servicefile= takes precedence over PGSERVICEFILE',
+		sql => "SELECT 'connect7'",
+		expected_stdout => qr/connect7/);
+}
+
+done_testing();
-- 
2.34.1