add servicefile connection option feature

Author: ryogrid

doc/src/sgml/libpq.sgml

@@ -2320,6 +2320,19 @@ 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>
@@ -9596,7 +9609,8 @@ 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

src/interfaces/libpq/fe-connect.c

@@ -195,6 +195,9 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
 		"Database-Service", "", 20,
 	offsetof(struct pg_conn, pgservice)},
 
+	{"servicefile", "PGSERVICEFILE", NULL, NULL,
+	"Database-Service-File", "", 64, -1},
+
 	{"user", "PGUSER", NULL, NULL,
 		"Database-User", "", 20,
 	offsetof(struct pg_conn, pguser)},
@@ -5904,6 +5907,7 @@ 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;
@@ -5923,11 +5927,18 @@ parseServiceInfo(PQconninfoOption *options, PQExpBuffer errorMessage)
 		return 0;
 
 	/*
-	 * Try PGSERVICEFILE if specified, else try ~/.pg_service.conf (if that
-	 * exists).
+	 * First, check servicefile option on connection string. Second, check
+	 * PGSERVICEFILE environment variable. Finally, check ~/.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
 	{
 		char		homedir[MAXPGPATH];
@@ -6089,6 +6100,16 @@ 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.

src/interfaces/libpq/t/006_service.pl

@@ -7,7 +7,7 @@
 use Test::More;
 
 # This tests scenarios related to the service name and the service file,
-# for the connection options and their environment variables.
+# for the connection options, servicefile options and their environment variables.
 
 my $node = PostgreSQL::Test::Cluster->new('node');
 $node->init;
@@ -146,6 +146,69 @@
 	unlink($srvfile_default);
 }
 
+# Backslashes escaped path string for getting collect result at concatenation
+# for Windows environment
+my $srvfile_win_cared = $srvfile_valid;
+$srvfile_win_cared =~ s/\\/\\\\/g;
+
+# Check that servicefile option works as expected
+{
+	$dummy_node->connect_ok(
+		q{service=my_srv servicefile='} . $srvfile_win_cared . q{'},
+		'service=my_srv servicefile=...',
+		sql             => "SELECT 'connect3'",
+		expected_stdout => qr/connect3/
+	);
+
+	# Encode slashes and backslash
+	my $encoded_srvfile = $srvfile_valid =~ s{([\\/])}{
+		$1 eq '/' ? '%2F' : '%5C'
+	}ger;
+
+	# Additionaly encode a colon in servicefile path of Windows
+	$encoded_srvfile =~ s/:/%3A/g;
+
+	$dummy_node->connect_ok(
+		'postgresql:///?service=my_srv&servicefile=' . $encoded_srvfile,
+		'postgresql:///?service=my_srv&servicefile=...',
+		sql             => "SELECT 'connect4'",
+		expected_stdout => qr/connect4/
+	);
+
+	local $ENV{PGSERVICE} = 'my_srv';
+	$dummy_node->connect_ok(
+		q{servicefile='} . $srvfile_win_cared . q{'},
+		'envvar: PGSERVICE=my_srv + servicefile=...',
+		sql             => "SELECT 'connect5'",
+		expected_stdout => qr/connect5/
+	);
+
+	$dummy_node->connect_ok(
+		'postgresql://?servicefile=' . $encoded_srvfile,
+		'envvar: PGSERVICE=my_srv + postgresql://?servicefile=...',
+		sql             => "SELECT 'connect6'",
+		expected_stdout => qr/connect6/
+	);
+}
+
+# Check that servicefile option takes precedence over PGSERVICEFILE environment variable
+{
+	local $ENV{PGSERVICEFILE} = 'non-existent-file.conf';
+
+	$dummy_node->connect_fails(
+		'service=my_srv',
+		'service=... fails with wrong PGSERVICEFILE',
+		expected_stderr => qr/service file "non-existent-file\.conf" not found/
+	);
+
+	$dummy_node->connect_ok(
+		q{service=my_srv servicefile='} . $srvfile_win_cared . q{'},
+		'servicefile= takes precedence over PGSERVICEFILE',
+		sql             => "SELECT 'connect7'",
+		expected_stdout => qr/connect7/
+	);
+}
+
 $node->teardown_node;
 
 done_testing();