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Sympa and Active Directory

Some basic steps on running sympa on Ubuntu 12.04 and using Active Directories Global Directory to auto-populate groups.

Ubuntu Notes 

• apt-get install sympa will give you a 'mostly' working version
•  Chown -R /var/lib/sympa sympa 
• The suid wrapper does not work on 12.04. You will need to create a sudo wrapper instead:
• set use_fast_cgi 1 in /etc/sympa/wwsympa.conf
• /usr/lib/cgi-bin/sympa/wwsympa_sudo_wrapper.fcgi

• #!/usr/bin/perl
  
  exec '/usr/bin/sudo', '-E', '-u', 'sympa', '/usr/lib/cgi-bin/sympa/wwsympa.fcgi';
  

• In apache/conf.d/sympa, change:

  ScriptAlias /wws /usr/lib/cgi-bin/sympa/wwsympa_sudo_wrapper.pl

• add the following line to your sudoers file:
  

  www-data ALL = (sympa) SETENV: NOPASSWD: /usr/lib/cgi-bin/sympa/wwsympa.fcgi

• References:
• http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=682562
• https://bugs.launchpad.net/ubuntu/+source/sympa/+bug/977828

 LDAP/AD Bound Lists

• If you only have one domain, then you can just use the following and point at one of your domain controllers.
• If you want to use forest-wide groups, you have two options for accessing those groups.
• This will work this either security or distribution groups, however will NOT include nested membership.
  • In the ldap config for the group, point at the dc the group resides in. CHange suffix, host and user as appropriate, set use_ssl to yes, drop the :3268
  • Make the group universal and use the global directory (route I chose)
• LDAP Configuration

  include_ldap_query
  attrs mail
  filter memberof=Some Group,OU=...,OU=...,DC=research,DC=domain,DC=org
  ssl_ciphers ALL
  name any_name
  host dc1.mydomain.org:3268
  use_ssl no
  passwd your_password
  timeout 30
  suffix DC=domain,DC=org
  user   CN=Read Account,OU=...,DC=domain,DC=org
  ssl_version sslv2
  scope sub
  select first
  ssl_version tls
  

• References
• http://portal.gnenc.org/knowledge-base/-/wiki/Main/Sympa-Dynamic%20List%20Membership

SmartClient and Jersey/JAX-RS

Here's a good tutorial on using jax-rs to return smartclient compatible data sources.

Fun with DC's gis data, part 1

It looks like DC has kindly released quite a bit of gis data for public consumption. One of the more interesting sets is the regularly updated Owner Polygon dataset available from data.dc.gov. This is a shapefile containing current property records for everything in the District. Unfortunately, it's not available kml for easy display in google's tools. However the 70MB esri shapefile is available. Using Open Layers, PostGIS, and and GeoServer, we can get start displaying everything, but what if we want to use google maps and do things the hard way? To solve that, there's a few simple steps to allow polygon querying, selection, and display on google maps.

1. Import data into PostGIS
2. Create GIS servlet
3. Draw the data on google maps
4. Query PostGIS for google's lat/long
5. Select Properties from the map

We're going to work on step one today, import your data into PostGIS.
Prepare PostGIS
I'm running Ubuntu 11.04, PostgreSQL 8.4 with postGIS 1.5.1 installed from the default software repo.

1. PostGIS 1.5 manual
2. nad 83, maryland projection

psql (8.4.8)
Type "help" for help.

postgres=# create database propertymap;
CREATE DATABASE
postgres=# \q
~$ createlang plpgsql propertymap;
~$ cd /usr/share/postgresql/8.4/contrib/postgis-1.5/
postgis-1.5$ psql -f postgis.sql propertymap
postgis-1.5$ psql -f ../postgis_comments.sql propertymap;
postgis-1.5$ psql -f spatial_ref_sys.sql propertymap;

Convert Shapefile
Create a ton of insert statements using shp2pgsql:

poly$ shp2pgsql -s 926985 OwnerPly.shp ownertable > inserts.sql
Shapefile type: Polygon
Postgis type: MULTIPOLYGON[2]

If we look at the .prj file included, we see that the projection for the data is NAD_1983_StatePlane_Maryland_FIPS_1900. We need to add the projection from spatialreference.org in to our database

propertymap=# INSERT into spatial_ref_sys (srid, auth_name, .......66666666],UNIT["Meter",1.0]]');
INSERT 0 1
propertymap=# \i inserts.sql

Run your first query

propertymap=# select ownername,square,lot,premiseadd from ownertable where premiseadd like '%1600 PENNSYLVANIA%';
        ownername         | square | lot  |       premiseadd        
--------------------------+--------+------+-------------------------
 UNITED STATES OF AMERICA | 0187   | 0800 | 1600 PENNSYLVANIA AV NW
 UNITED STATES OF AMERICA | 0187   | 0802 | 1600 PENNSYLVANIA AV NW
 UNITED STATES OF AMERICA | 0187   | 0801 | 1600 PENNSYLVANIA AV NW

First, a little background on what we asked for. DC property records are based on square, suffix, and lot. Square generally refers to a city block and goes all the way back to the original city planning in the old part of the city. Lot is a lot within a square/suffix. For the most part, you can ignore suffix as it's rarely used. Next time, create a simple servlet to expose all of this.

Isolating Big Blue Button Video

This is a quick how to on manually connecting to a BBB video stream. Before we begin, here's a very, very quick background.

• Video streams are grouped under a conference-room specific url that has for format rtmp://host/video/roomID
• Each streaming component under BBB is available as a separate stream (ie, video, desktop, sip/audio, etc)
• BBB uses red5 under the hood to manage these streams
• Grab flowplayer here and the flowplayer rtmp client here

1. Connect to your room and start your webcam.
2. Tail /usr/share/red5/log/bigbluebutton.log and uou should see the following log lines:

   2011-07-11 18:14:54,871 [NioProcessor-1] DEBUG o.b.c.s.p.ParticipantsEventRecorder - A participant's status has changed 141 streamName 640x480141
   2011-07-11 18:14:54,919 [NioProcessor-1] DEBUG o.b.c.s.p.ParticipantsService - Setting participant status ec0449a0-b5d1-4ca5-bfdf-d118d8bc2299 141 hasStream true

   • ec0449a0-b5d1-4ca5-bfdf-d118d8bc2299 or similar is the room id
   • 640x480141 is the stream id you need
3. Download and place flowplayer-...swf, flowplayer.rtmp-...swf, and flowplayer-...min.js into a directory.
4. Create a web page as follows:

<meta equiv="content-type" content="text/html; charset=UTF-8">
       <script type="text/javascript" src="flowplayer-3.2.6.min.js"></script>
       <title>Minimal Flowplayer setup</title>


<div id="player"></div>

<script language="javascript">
$f("player", "flowplayer-3.2.7.swf",
{
clip: {
        url: '640x480141',
        live: true,
        autoBuffering: false,
        bufferLength: 1,
        provider: 'rtmp'
      },

       plugins: {

               // here is our rtpm plugin configuration
               rtmp: {
                       url: 'flowplayer.rtmp-3.2.3.swf',
                       netConnectionUrl: 'rtmp://your_server/video/ec0449a0-b5d1-4ca5-bfdf-d118d8bc2299'
               }
       }
});
</script>

5. Load up your web page and you should see the streaming video.

log4j and Pivot

Here's a simple way to consume log4j messages in pivot for use in a log console or similar. First create a custom appender which sents a log message to the pivot message bus.

public class MessageBusAppender extends AppenderSkeleton {
    
    @Override
    protected void append(LoggingEvent event) {
        MessageBus.sendMessage(new LogMessage(layout, event));
    }

    @Override
    public boolean requiresLayout() {
        return true;
    }

    @Override
    public void close() {
       //nop
    }

}

public class LogMessage {

    private Layout logLayout;
    private LoggingEvent event;

    public LoggingEvent getEvent() {
        return event;
    }

    public Layout getLogLayout() {
        return logLayout;
    }

    public LogMessage(Layout logLayout, LoggingEvent event) {
        this.logLayout = logLayout;
        this.event = event;
    }
    
}

In any component needs to display log messages, just listen for the messages and update as appropriately. Here's an example updating a textpane:

public class LogPane extends Border {

    @BXML
    private TextPane logTxt;
    @BXML
    private PushButton clearBtn;
...
...
        logTxt.setDocument(new Document());

        MessageBus.subscribe(LogMessage.class, new MessageBusListener() {

            public void messageSent(final LogMessage message) {
                ApplicationContext.queueCallback(new Runnable() {

                    @Override
                    public void run() {
                        String text = message.getLogLayout().format(message.getEvent());
                        logTxt.getDocument().add(new Paragraph(text));
                        if (message.getEvent().getThrowableInformation() != null)
                        {
                            StringBuilder sb = new StringBuilder();
                            for (String s : message.getEvent().getThrowableInformation().getThrowableStrRep())
                            {
                                sb.append("  ");
                                sb.append(s);
                                sb.append("\n");
                            }
                            logTxt.getDocument().add(new Paragraph(sb.toString()));
                        }
                    }
                });
            }
        });

        clearBtn.getButtonPressListeners().add(new ButtonPressListener() {

            public void buttonPressed(Button button) {
                logTxt.setDocument(new Document());

            }
        });
 ...
 ...
}

Now tie it together in your log4j config:

log4j.rootLogger=ERROR, Pivot

log4j.appender.Pivot=sample.MessageBusAppender
log4j.appender.Pivot.layout=org.apache.log4j.PatternLayout
log4j.appender.Pivot.layout.ConversionPattern=%-6r [%15.15t] %-5p %30.30c %x - %m%n

Counting bits

Here's a simple input stream which will tell you the current position. You should insert this after any buffered input streams if you want an accurate position after a read.

public class CountingInputStream extends PushbackInputStream {

    private long bytesRead;

    public CountingInputStream(InputStream is) {
        super(is);
    }
    public CountingInputStream(InputStream is,int len) {
        super(is,len);
    }

    public long getPosition() {
        return bytesRead;
    }

    @Override
    public void unread(byte[] b, int off, int len) throws IOException {
        bytesRead -= len;
        super.unread(b, off, len);
    }

    @Override
    public void unread(int b) throws IOException {
        bytesRead--;
        super.unread(b);
    }

    @Override
    public void unread(byte[] b) throws IOException {
        bytesRead -= b.length;
        super.unread(b);
    }

    @Override
    public boolean markSupported() {
        return false;
    }

    @Override
    public synchronized void reset() throws IOException {
        throw new IOException("Mark not supported");
    }

    @Override
    public int read() throws IOException {
        int rd = super.read();
        if (rd != -1) {
            bytesRead++;
        }
        return rd;
    }

    @Override
    public int read(byte[] b) throws IOException {
        int read = super.read(b);
        if (read != -1) {
            bytesRead += read;
        }
        return read;
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        int read = super.read(b, off, len);
        if (read != -1) {
            bytesRead += read;
        }
        return read;
    }

    @Override
    public long skip(long n) throws IOException {
        long skipped = super.skip(n);
        bytesRead += skipped;
        return skipped;
    }
}