pg_isready 8.19 KB
Newer Older
qhoangxuan's avatar
qhoangxuan committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281
#!/usr/bin/perl -w
# Call a PostgreSQL client program with the version, cluster and default
# database specified in ~/.postgresqlrc or
# /etc/postgresql-common/user_clusters.
#
# (C) 2005-2009 Martin Pitt <mpitt@debian.org>
# (C) 2013-2014 Christoph Berg <myon@debian.org>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.

use strict;
use POSIX;
use PgCommon;

my ($version, $cluster, $db, $port, $host);

$host = $ENV{'PGHOST'};

# Check for PGCLUSTER in %ENV
if (defined $ENV{'PGCLUSTER'}) {
    ($version, $cluster) = split ('/', $ENV{'PGCLUSTER'}, 2);
    error 'Invalid version specified with $PGCLUSTER' unless version_exists $version;
    error 'No cluster specified with $PGCLUSTER' unless $cluster;
}

# Check for --cluster argument and filter it out, and check if --port is specified
my $port_specified = exists $ENV{'PGPORT'};
for (my $i = 0; $i <= $#ARGV; ++$i) {
    last if $ARGV[$i] eq '--';

    if ($ARGV[$i] eq '--cluster') {
        error '--cluster option needs an argument (<version>/<cluster>)' if ($i >= $#ARGV);

        ($version, $cluster) = split ('/', $ARGV[$i+1], 2);
	$host = undef; # --cluster overrides $PGHOST env var
        error 'Invalid version specified with --cluster' unless version_exists $version;
        error 'No cluster specified with --cluster' unless $cluster;

        splice @ARGV, $i, 2;
        last;
    } elsif ($ARGV[$i] =~ /^--cluster=(\d+\.\d)\/(.+)/) {
        ($version, $cluster) = ($1, $2);
        $host = undef; # --cluster overrides $PGHOST env var
        error 'Invalid version specified with --cluster' unless version_exists $version;
        error 'No cluster specified with --cluster' unless $cluster;

        splice @ARGV, $i, 1;
        last;
    }

    $port_specified = 1 if $ARGV[$i] =~ /^--port\b/ || $ARGV[$i] =~ /^-\w*p\w*\d*$/;
    $host = '.from.commandline' if $ARGV[$i] =~ /^--host\b/ || $ARGV[$i] =~ /^-\w*h\w*$/;
}

# Determine $version, $cluster, $db, $port from map files
($version, $cluster, $db) = user_cluster_map() unless $cluster;

# check if we have a network cluster
if (!$host && $cluster && !cluster_exists $version, $cluster) {
    if ($cluster =~ /^(\S+):(\d*)$/) {
	$host = $1;
	$port = $2 || 5432;
    } else {
	error 'Specified cluster does not exist locally and does not specify a remote cluster';
    }
}

if (!$host && $cluster) {
    $port = get_cluster_port($version, $cluster);

    unless ($ENV{'PGHOST'}) {
        # default to cluster specific Unix socket directory
        $ENV{'PGHOST'} = get_cluster_socketdir $version, $cluster;
    }
}

$ENV{'PGSYSCONFDIR'} = '/etc/postgresql-common' if !$ENV{'PGSYSCONFDIR'};
$ENV{'PGPORT'} = $port if $port && !$ENV{'PGPORT'};
$ENV{'PGDATABASE'} = $db if $db && !$ENV{'PGDATABASE'};
$ENV{'PGHOST'} = $host if $host && $host ne '.from.commandline';

# if we only have a port, but no version here, use the latest version
# TODO: this could be improved by better argument parsing and mapping back the
# port to a cluster version/name
if (!$version and $port_specified) {
    $version = get_newest_version;
}

unless ($version) {
    if (get_versions) {
	error 'No existing local cluster is suitable as a default target. Please see man pg_wrapper(1) how to specify one.';
    } else {
	error 'You must install at least one postgresql-client-<version> package.';
    }
}

error 'Invalid PostgreSQL cluster version' unless -d "$PgCommon::binroot$version";
my $cmdname = (split '/', $0)[-1];
my $cmd;

# for psql we always want the latest version, as this is backwards compatible
# to every major version that that we support
if ($cmdname eq 'pg_wrapper') {
    error "pg_wrapper should not be called directly, but through a symlink";
} elsif ($cmdname =~ /^(psql|pg_archivecleanup|pg_isready)$/) {
    $cmd = get_program_path ($cmdname, get_newest_version);
} else {
    $cmd = get_program_path ($cmdname, $version);
}

# libreadline is a lot better than libedit, so prefer that
if ($cmdname eq 'psql' and not $PgCommon::rpm) {
    my @readlines;
    # non-multiarch path
    @readlines = sort(</lib/libreadline.so.?>);

    unless (@readlines) {
	# get multiarch dir for our architecture
	if (open PS, '-|', '/usr/bin/ldd', $cmd) {
	    my $out;
	    read PS, $out, 10000;
	    close PS;
	    if ($out =~ m!/libreadline.so!) {
		# already linked against libreadline
		@readlines = ();
	    }
	    else
	    {
		my ($lib_path) = $out =~ m!(/lib/.*)/libedit.so!;

		@readlines = sort(<$lib_path/libreadline.so.?>);
	    }
	}
    }

    if (@readlines) {
	$ENV{'LD_PRELOAD'} = ($ENV{'LD_PRELOAD'} or '') . ':' . $readlines[-1];
    }
}

error "pg_wrapper: $cmdname was not found in $PgCommon::binroot$version/bin" unless $cmd;
unshift @ARGV, $cmd;
exec @ARGV;

__END__

=head1 NAME

pg_wrapper - wrapper for PostgreSQL client commands

=head1 SYNOPSIS

I<client-program> [B<--cluster> I<version>/I<cluster>] [...]

(I<client-program>: B<psql>, B<createdb>, B<dropuser>, and all other client
programs installed in C</usr/lib/postgresql/>I<version>C</bin>).

=head1 DESCRIPTION

This program is run only as a link to names which correspond to PostgreSQL
programs in C</usr/lib/postgresql/>I<version>C</bin>. It determines the
configured cluster and database for the user and calls the appropriate version
of the desired program to connect to that cluster and database, supplying any
specified options to that command.

The target cluster is selected by the following means, in descending order of
precedence:

=over

=item 1.

explicit specification with the B<--host> option

=item 2.

explicit specification with the B<--cluster> option

=item 3.

if the B<PGHOST> environment variable is set, no further cluster selection is
performed. The default PostgreSQL version and port number (from the command
line, the environment variable B<PGPORT>, or default 5432) will be used.

=item 4.

explicit specification with the B<PGCLUSTER> environment variable

=item 5.

matching entry in C<~/.postgresqlrc> (see L<postgresqlrc(5)>), if that
file exists

=item 6.

matching entry in C</etc/postgresql-common/user_clusters> (see
L<user_clusters(5)>), if that file exists

=item 7.

If only one local cluster exists, that one will be selected.

=item 8.

If several local clusters exist, the one listening on the default port 5432
will be selected.

=back

If none of these rules match, B<pg_wrapper> aborts with an error.

For B<psql>, B<pg_archivecleanup>, and B<pg_isready>, B<pg_wrapper> will always use the binary from
the newest PostgreSQL version installed, as these are downwards compatible.

=head1 OPTIONS

=over

=item B<--cluster> I<version>B</>I<cluster>

I<cluster> is either the name of a local cluster, or takes the form
I<host>:I<port> for a remote cluster. If I<port> is left empty (i. e. you just
specify I<host:>), it defaults to 5432.

=back

=head1 ENVIRONMENT

=over

=item B<PGCLUSTER>

If C<$PGCLUSTER> is set, its value (of the form I<version>/I<cluster>)
specifies the desired cluster, similar to the B<--cluster> option. However, if
B<--cluster> is specified, it overrides the value of C<$PGCLUSTER>.

=item B<PG_CLUSTER_CONF_ROOT>

This specifies an alternative base directory for cluster configurations. This
is usually C</etc/postgresql/>, but for testing/development purposes you can
change this to point to e. g. your home directory, so that you can use the
postgresql-common tools without root privileges.

=item B<PGSYSCONFDIR>

This is the location of PostgreSQL's and postgresql-common's global
configuration (e. g. C<pg_service.conf>, L<user_clusters(5)>). The default is
C</etc/postgresql-common/>.

=back

=head1 FILES

=over

=item C</etc/postgresql-common/user_clusters>

stores the default cluster and database for users and groups as set by
the administrators. 

=item C<$HOME/.postgresqlrc>

stores defaults set by the user himself.

=back

=head1 SEE ALSO

L<user_clusters(5)>, L<postgresqlrc(5)>

=head1 AUTHOR

Martin Pitt L<E<lt>mpitt@debian.orgE<gt>>