[rt-users] Contribution: Connecting SVN and RT

[Josh Narins]

I've worked at a lot of places, even with people who supposedly knew what they were doing. I appreciate the best practices model described in this paper: http://www.perforce.com/perforce/papers/bestpractices.html

I'd describe the difference between perforce and subversion thusly: perforce lacks a decent "svn status" command but closely integrates the concept of "changesets"  to its workflow. A changeset is connected group of changes across one(uninterestingly) or more files representing one feature or fix.

So, here at my new company, I developed an integrated incident, problem and change management system using RT and Subversion. I think it might even work better with git, but that's how it goes, sometimes.

Below is how I keep subversion changes tied into RT. Later, tickets are released to QA and then production via their ticket number. By using the mainline, rather than promotion, model, certain things remain relatively sane over time. All commits go to the trunk branch, and please don't commit anything that breaks anyone else's code. :)

And, yes, I probably should have used placeholders and bind variables. However, it isn't like the input is coming from complete strangers.

#!/usr/bin/perl

# if the file's commit message includes a ticket #, add those tickets to RT
# svn commit -m "#123 these files get attached to ticket #123"

# the id of the 'Files' customfield in the customfields table
# yes, it could be a subselect
our $customfield = 5;
our $path_to_log = "/path/to/file";

use strict;
use warnings;
use DBI;
use DBD::Pg;
use Data::Dumper qw(Dumper);
use constant SVNLOOK => '/usr/bin/svnlook';

# include BEGIN block in your commit hooks
# to prevent people from getting funny and providing
# their own versions of perl libraries, especially
# important if the subversion post-commit user has
# any privileges
BEGIN {
    pop @INC;    # removes .
    @INC = grep { !m{^/home} } @INC;
}

my $log = open_log($path_to_log);
my ($repos, $rev) = @ARGV;
print $log "Repo: $repos\nRev : $rev\n";
my $dbh = DBI->connect('dbi:Pg:dbname=rt3', 'rt_user', 'rt_pass');
print $log "Got db connection\n";
exit(1) unless my ($author, $ticket) = in_log_message($repos, $rev);
print $log join "\n", '-' x 80, "Author: $author\nTicket: $ticket", '';
exit(1) unless my $rt_user_id = find_author_in_rt($dbh, $author);
print $log "RT User ID: $rt_user_id\n";
my ($adds, $dels, $mods) = find_changed_files($repos, $rev);

# maybe just a property change, or something
exit unless %$adds || %$dels || %$mods;

my ($old_row_id, %files) = files_currently_in_ticket($dbh, $ticket);
my $exit = update_ticket(
    $rev,    $dbh,  $old_row_id, $rt_user_id, $ticket,
    \%files, $adds, $mods,       $dels
);
exit;

# nothing but subs

sub update_ticket {
    my (
        $rev,     $dbh,  $old_row_id, $rt_user_id, $ticket,
        $current, $adds, $mods,       $dels
    ) = @_;

    print $log Dumper(\@_);
    my %files;
    foreach my $file (keys %$current) {
        next if !$file or exists $dels->{$file};
        $files{$file} = $current->{$file};
    }

    # overwrite revision if modified
    foreach my $file (keys %$adds, keys %$mods) {
        next if !$file or exists $dels->{$file};
        $files{$file} = $rev;
    }

    my $raw = join "\n", map { $_ . '@' . $files{$_} } keys %files;
    my ($content, $largecontent, $type, $encoding) =
      length($raw) > 255
      ? ('', $raw, 'text/plain', 'none')
      : ($raw, '', '', '');

    my $query = "
       insert into objectcustomfieldvalues(
         customfield,objecttype,objectid,content,largecontent,contenttype,
         contentencoding,creator,created,lastupdatedBy,lastupdated
       ) values (
         $customfield,'RT::Ticket',$ticket,'$content','$largecontent','$type',
         '$encoding',$rt_user_id,now(),$rt_user_id,now()
       )
    ";
    print $log $query, "\n";
    my $sth = $dbh->prepare($query);
    $sth->execute() or die $sth->errstr;
    if ($old_row_id) {
        my $update = "
         update objectcustomfieldvalues
             set disabled = 1
           where id = $old_row_id
        ";
        $sth = $dbh->prepare($update);
        my $rv = $sth->execute();
        die $sth->errstr unless defined $rv;
    }
}

sub files_currently_in_ticket {
    my ($dbh, $ticket) = @_;

    my $sth = $dbh->prepare("
      select id, content, contenttype, largecontent
        from objectcustomfieldvalues
       where objecttype  = 'RT::Ticket'
         and objectid    = $ticket
         and customfield = $customfield
         and disabled    = 0
    ");
    $sth->execute();
    return 0 unless $sth->rows;

    my $row     = $sth->fetchrow_hashref();
    my $content = $row->{largecontent} || $row->{content};
    my $id      = $row->{id};
    print $log "Content: $content\n";
    my %files;
    my @lines = grep /\S/, split /\n/, $content;

    # some of this block relates to handling
    # earlier versions of the commit hook
    foreach my $line (@lines) {
        $line =~ s/^\s*//;
        $line =~ s/\s*$//;
        next unless $line;
        if ($line =~ s/\@(\d+)//) {
            $files{$line} = $1;
        } else {
            $files{$line} = '';
        }
    }
    print $log Dumper(\%files);
    return 0 unless keys %files;
    return ($id, %files);
}


sub in_log_message {
    my ($repos, $rev) = @_;
    my @svnlooklines = read_from_process(SVNLOOK, 'info', $repos, '-r', $rev);
    my $author = shift @svnlooklines;
    shift @svnlooklines for 1 .. 2;
    my $log = join "\n", @svnlooklines;
    if ($log =~ /\#(\d+)/) {
        return ($author, $1);
    }
    return;
}

sub find_author_in_rt {
    my ($dbh, $author) = @_;
    my $sth = $dbh->prepare("select id from users where name = '$author'");
    $sth->execute();
    return unless $sth->rows();
    my $row = $sth->fetchrow_hashref();
    return $row->{id};
}

sub find_changed_files {
    my ($repos, $rev) = @_;
    my @svnlooklines =
      read_from_process(SVNLOOK, 'changed', $repos, '-r', $rev);

    # Parse the changed nodes.
    my %adds;
    my %dels;
    my %mods;
    foreach my $line (@svnlooklines) {
        my $path = '';
        my $code = '';

        # Split the line up into the modification code and path, ignoring
        # property modifications.
        if ($line =~ /^(.).  (.*)$/) {
            $code = $1;
            $path = $2;
        }

        (my $subpath = $path) =~ s{^.*?/rosalind2/}{};
        if ($code eq 'A') {
            $adds{$subpath}++;
        } elsif ($code eq 'D') {
            $dels{$subpath}++;
        } else {
            $mods{$subpath}++;
        }
    }
    return (\%adds, \%dels, \%mods);
}


sub open_log {
    my $file = shift;
    umask 0002;
    open my $fh, ">>$file" or die "Coudln't open `$file': $!";
    return $fh;
}

# the below is copied from commit-email.pl from subversion

# Start a child process safely without using /bin/sh.
sub safe_read_from_pipe {
    unless (@_) {
        croak "$0: safe_read_from_pipe passed no arguments.\n";
    }

    my $pid = open(SAFE_READ, '-|');
    unless (defined $pid) {
        die "$0: cannot fork: $!\n";
    }
    unless ($pid) {
        open(STDERR, ">&STDOUT")
          or die "$0: cannot dup STDOUT: $!\n";
        exec(@_)
          or die "$0: cannot exec `@_': $!\n";
    }
    my @output;
    while (<SAFE_READ>) {
        s/[\r\n]+$//;
        push(@output, $_);
    }
    close(SAFE_READ);
    my $result = $?;
    my $exit   = $result >> 8;
    my $signal = $result & 127;
    my $cd     = $result & 128 ? "with core dump" : "";
    if ($signal or $cd) {
        warn "$0: pipe from `@_' failed $cd: exit=$exit signal=$signal\n";
    }
    if (wantarray) {
        return ($result, @output);
    } else {
        return $result;
    }
}


# Use safe_read_from_pipe to start a child process safely and return
# the output if it succeeded or an error message followed by the output
# if it failed.
sub read_from_process {
    unless (@_) {
        croak "$0: read_from_process passed no arguments.\n";
    }
    my ($status, @output) = &safe_read_from_pipe(@_);
    if ($status) {
        return ("$0: `@_' failed with this output:", @output);
    } else {
        return @output;
    }
}















Josh Narins

Director of Application Development
SeniorBridge
845 Third Ave
7th Floor
New York, NY 10022
Tel: (212) 994-6194
Fax: (212) 994-4260
Mobile: (917) 488-6248
jnarins at seniorbridge.com
seniorbridge.com<http://www.seniorbridge.com/>

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