Allow passing extra options to initdb for tests

Setting the environment variable PG_TEST_INITDB_EXTRA_OPTS passes
extra options to initdb run by pg_regress or
PostgreSQL::Test::Cluster's init.

This can be useful for a wide variety of uses, like running all tests
with checksums enabled, or with JIT enabled, or with different GUC
settings, or with different locale settings.  (Not all tests are going
to pass with arbitrary options, but it is useful to run this against
specific test suites.)

Reviewed-by: Ian Lawrence Barwick <barwick@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/d4d2ad9f-1c1d-47a1-bb4d-c10a747d4f15%40eisentraut.org

Author: petere

doc/src/sgml/regress.sgml

@@ -390,12 +390,37 @@ make check LANG=C ENCODING=EUC_JP
    <title>Custom Server Settings</title>
 
    <para>
-    Custom server settings to use when running a regression test suite can be
+    There are several ways to use custom server settings when running a test
+    suite.  This can be useful to enable additional logging, adjust resource
+    limits, or enable extra run-time checks such as <xref
+    linkend="guc-debug-discard-caches"/>.  But note that not all tests can be
+    expected to pass cleanly with arbitrary settings.
+   </para>
+
+   <para>
+    Extra options can be passed to the various <command>initdb</command>
+    commands that are run internally during test setup using the environment
+    variable <envar>PG_TEST_INITDB_EXTRA_OPTS</envar>.  For example, to run a
+    test with checksums enabled and a custom WAL segment size and
+    <varname>work_mem</varname> setting, use:
+<screen>
+make check PG_TEST_INITDB_EXTRA_OPTS='-k --wal-segsize=4 -c work_mem=50MB'
+</screen>
+   </para>
+
+   <para>
+    For the core regression test suite and other tests driven by
+    <command>pg_regress</command>, custom run-time server settings can also be
     set in the <varname>PGOPTIONS</varname> environment variable (for settings
-    that allow this):
+    that allow this), for example:
 <screen>
 make check PGOPTIONS="-c debug_parallel_query=regress -c work_mem=50MB"
 </screen>
+    (This makes use of functionality provided by libpq; see <xref
+    linkend="libpq-connect-options"/> for details.)
+   </para>
+
+   <para>
     When running against a temporary installation, custom settings can also be
     set by supplying a pre-written <filename>postgresql.conf</filename>:
 <screen>
@@ -405,11 +430,6 @@ make check EXTRA_REGRESS_OPTS="--temp-config=test_postgresql.conf"
 </screen>
    </para>
 
-   <para>
-    This can be useful to enable additional logging, adjust resource limits,
-    or enable extra run-time checks such as <xref
-    linkend="guc-debug-discard-caches"/>.
-   </para>
   </sect2>
 
   <sect2 id="regress-run-extra-tests">

src/test/perl/PostgreSQL/Test/Cluster.pm

@@ -114,6 +114,7 @@ use Socket;
 use Test::More;
 use PostgreSQL::Test::Utils          ();
 use PostgreSQL::Test::BackgroundPsql ();
+use Text::ParseWords                 qw(shellwords);
 use Time::HiRes                      qw(usleep);
 use Scalar::Util                     qw(blessed);
 
@@ -519,6 +520,12 @@ sub init
 	$params{allows_streaming} = 0 unless defined $params{allows_streaming};
 	$params{has_archiving} = 0 unless defined $params{has_archiving};
 
+	my $initdb_extra_opts_env = $ENV{PG_TEST_INITDB_EXTRA_OPTS};
+	if (defined $initdb_extra_opts_env)
+	{
+		push @{ $params{extra} }, shellwords($initdb_extra_opts_env);
+	}
+
 	mkdir $self->backup_dir;
 	mkdir $self->archive_dir;
 

src/test/regress/pg_regress.c

@@ -2306,6 +2306,7 @@ regression_main(int argc, char *argv[],
 		const char *keywords[4];
 		const char *values[4];
 		PGPing		rv;
+		const char *initdb_extra_opts_env;
 
 		/*
 		 * Prepare the temp instance
@@ -2327,6 +2328,8 @@ regression_main(int argc, char *argv[],
 		if (!directory_exists(buf))
 			make_directory(buf);
 
+		initdb_extra_opts_env = getenv("PG_TEST_INITDB_EXTRA_OPTS");
+
 		initStringInfo(&cmd);
 
 		/*
@@ -2339,7 +2342,7 @@ regression_main(int argc, char *argv[],
 		 * duplicate it until we require perl at build time.
 		 */
 		initdb_template_dir = getenv("INITDB_TEMPLATE");
-		if (initdb_template_dir == NULL || nolocale || debug)
+		if (initdb_template_dir == NULL || nolocale || debug || initdb_extra_opts_env)
 		{
 			note("initializing database system by running initdb");
 
@@ -2352,6 +2355,8 @@ regression_main(int argc, char *argv[],
 				appendStringInfoString(&cmd, " --debug");
 			if (nolocale)
 				appendStringInfoString(&cmd, " --no-locale");
+			if (initdb_extra_opts_env)
+				appendStringInfo(&cmd, " %s", initdb_extra_opts_env);
 			appendStringInfo(&cmd, " > \"%s/log/initdb.log\" 2>&1", outputdir);
 			fflush(NULL);
 			if (system(cmd.data))