gbrowse_attach_slaves.pl

#!/usr/bin/perl
use strict;
use constant RENDERFARM_CONF         => '/srv/gbrowse/etc/renderfarm.conf';
use constant SNAPSHOT_MAP            => '/srv/gbrowse/etc/species_volume_map.txt';
use constant IMAGE_MAP               => '/srv/gbrowse/etc/ami_map.txt';
use constant SLAVE_SECURITY_GROUP    => 'GBrowseSlave';
use constant MASTER_SECURITY_GROUP   => 'GBrowseMaster';
use constant PORT_RANGE              => '8100-8105';

# This is called on the master to launch instances.
# It discovers which species are mounted
# on the current instance, snapshots them, and
# attaches them to the slave(s).
# EC2_ACCESS_KEY and EC2_SECRET_KEY must be defined

$ENV{PYTHONPATH}='/usr/local/lib/python2.6/dist-packages';

my $SLAVE_COUNT = shift || 1;

my @mounts       = get_species_mounts();
my $snapshot_map = get_snapshot_map(\@mounts);
my $ami_map      = get_ami_map();

# set up the block devices that need to be attached
my @devices = map {"/dev/sd$_"} ('h'..'z');
my $i = 0;
my @block_args    = ('-b','/dev/sdg=:0:true',map {
    my $device    = $devices[$i++];
    my $species   = $_->[1];
    my $snapshot  = $snapshot_map->{$species};
    $snapshot ? ('-b',"${device}=${snapshot}:0:true") : ();  # all these volumes are terminate-on-delete
} @mounts);

my $ami      = $ami_map->{GBROWSE_SLAVE} or die "Couldn't look up current AMI for the slave";
my $key      = get_keypair();
my $security = get_security_group();

my @command = ('euca-run-instances','-k',$key,'-g',$security,@block_args,'-t','t1.micro','-n',$SLAVE_COUNT,$ami);

# now get the IP addresses of these instances
my @instances;
open OUTPUT,'-|' or exec @command;
while (<OUTPUT>) {
    chomp;
    next unless /^INSTANCE\s+(\S+)/;
    push @instances,$1;
}
close OUTPUT;

my %ips;
while (keys %ips < $SLAVE_COUNT) {
    sleep 5;
    chomp (my $output = `euca-describe-instances @instances`);
    for my $line (split "\n",$output) {
	next unless $line =~ /^INSTANCE/;
	my @fields = split "\t",$line;
	$ips{$fields[4]}++ if $fields[4];
    }
}

open F,'>',RENDERFARM_CONF or die "Can't write ",RENDERFARM_CONF,": $!";
print F "renderfarm = 1\n";
print F "remote renderer =\n";
my ($low,$hi) = split /-/,PORT_RANGE;
foreach my $ip ('localhost',keys %ips) {
    my $slaves = join ' ',map {"http://${ip}:$_"} ($low..$hi);
    print F " $slaves\n";
}
close F;

system "sudo /etc/init.d/apache2 restart";
exit 0;

# sub get_snapshot_map {
#     my %map;
#     open F,SNAPSHOT_MAP or die "Can't open ",SNAPSHOT_MAP,": $!";
#     while (<F>) {
# 	chomp;
# 	next if /^#/;
# 	my ($mount,$snap_id,$vol_label) = split /\s+/;
# 	$map{$mount} = [$snap_id,$vol_label];
#     }
#     close F;
#     return \%map;
# }

sub get_snapshot_map {
    my $mounts = shift;
    my (%vol2snap,%mount2vol,%map);

    chomp (my $instance = `curl -s http://169.254.169.254/latest/meta-data/instance-id`);
    chomp (my $volumes  = `euca-describe-volumes`);

    # get volume and snapshot id for each mounted volume
    for my $line (split "\n",$volumes) {
	if ($line =~ /^VOLUME/) {
	    my ($vol,$snap) = (split /\s+/,$line)[1,3];
	    $vol2snap{$vol} = $snap;
	} elsif ($line =~ /^ATTACHMENT/) {
	    next unless $line =~ /\s$instance\s/;
	    my ($vol,$mount) = (split /\s+/,$line)[1,3];
	    $mount2vol{$mount} = $vol;
	}
    }

    for my $m (@$mounts) {
	my ($device,$species) = @$m;
	$device =~ s/\d+$//;
	my $vol  = $mount2vol{$device} or next;
	my $snap = $vol2snap{$vol};
	$map{$species} = $snap;
    }

    return \%map;
}

sub get_species_mounts {
    my @mounts;
    open F,'/proc/mounts' or die "Can't open /proc/mounts: $!";
    while (<F>) {
	chomp;
	my ($dev,$mount_point,@etc) = split /\s+/;
	next unless $mount_point =~ m!/srv/gbrowse/species/([^/]+)!;
	push @mounts,[$dev,$1];
    }
    close F;
    return @mounts;
}

sub get_ami_map {
    my %map;
    open F,IMAGE_MAP or die "Can't open ",IMAGE_MAP,": $!";
    while (<F>) {
	chomp;
	next if /^#/;
	my ($role,$ami) = split /\s+/;
	$map{$role} = $ami;
    }
    close F;
    return \%map;
}

sub get_keypair {
    my $out = `curl -s http://169.254.169.254/latest/meta-data/public-keys/`;
    my ($keyname) = $out =~ /0=(.+)/;
    return $keyname;
}

sub get_security_group {
    my $ssg        = SLAVE_SECURITY_GROUP;
    my $msg        = MASTER_SECURITY_GROUP;
    my $range      = PORT_RANGE;
    chomp (my $result   = `euca-describe-group $ssg`);
    unless ($result) {
	$result = `euca-add-group -d'security group for gbrowse render slaves allows ssh and ports $range' $ssg`;
	die "Couldn't create security group for $ssg" unless $result =~ /^GROUP/;
    }
    chomp (my $ip = `curl -s http://169.254.169.254/latest/meta-data/local-ipv4/`);
    $result = `euca-authorize -P tcp -p 22 -s $ip/32 $ssg`;	
    die $result unless $result =~ /PERMISSION/;
    $result = `euca-authorize -P tcp -p $range -o $msg $ssg`;
    die $result unless $result =~ /PERMISSION/;
    return $ssg;
}