Install Ajaxterm on Gentoo

These are the steps I followed, they should complement the explanation of the wiki of Ajaxterm, created by Antony Lesuisse.

1. setup a Dyndns account and ddclient

Publish the IP address of your router first with these steps:

Visit Dyndns, register an account and your host. Choose a freely available DNS name like delta.dyndns.org. On your Gentoo box, install ddclient

USE="ssl" emerge ddclient
su
vi /etc/ddclient/ddclient.conf

/etc/init.d/ddclient start
rc-update add ddclient default

ACCEPT_KEYWORDS="~x86" emerge ajaxterm
/etc/init.d/ajaxterm start

vi /etc/services

ajaxterm     8022/tcp
ajaxterm     8022/udp

rc-update add ajaxterm default

su
echo 'APACHE2_MODULES="authz_host actions alias auth_basic
auth_digest authn_anon authn_dbd authn_dbm authn_default
authn_file authz_dbm authz_default authz_groupfile
authz_host authz_owner authz_user autoindex cache dav dav_fs
dav_lock dbd deflate dir disk_cache env expires ext_filter
file_cache filter headers ident imagemap include info
log_config logio mem_cache mime mime_magic negotiation proxy
proxy_ajp proxy_balancer proxy_connect proxy_http rewrite
setenvif speling status unique_id userdir usertrack
vhost_alias"' >> /etc/make.conf

 
 USE="ssl" emerge -av apache

vi /etc/conf.d/apache2
[...]
APACHE2_OPTS="-D DEFAULT_VHOST -D INFO -D SSL -D
SSL_DEFAULT_VHOST -D PROXY -D P
ROXY_HTTP" 
[...]

vi /etc/apache2/vhosts.d/00_default_ssl_vhost.conf
[...]
VirtualHost *:443>
       ServerName localhost
       SSLEngine On

 
        ProxyRequests Off
       <Proxy *>
               Order deny,allow
               Allow from all
       </Proxy>
       ProxyPass /ajaxterm/ http://localhost:8022/
       ProxyPassReverse /ajaxterm/ http://localhost:8022/
    </VirtualHost>

 
 [...]

/etc/init.d/apache2 start
rc-update add apache2 default

openssl req -new > new.cert.csr

openssl rsa -in privkey.pem -out new.cert.key

openssl x509 -in new.cert.csr -out new.cert.cert -req
-signkey new.cert.key -days 3650

vi /etc/apache2/vhosts.d/00_default_ssl_vhost.conf
[...]
SSLCertificateFile /path/to/certs/new.cert.cert
SSLCertificateKeyFile /path/to/certs/new.cert.key
[...]

Have fun!

Cescozen

Cescozen is a game invented by Cesco. If you point your browser to the initial page of the game, you'll encounter very difficult enigmas that wait for a solution (note: the game is in Italian). To answer each quiz, you put the solution on the URL, so that you move one directory down the tree. To me and Virgi, it took about a week investing 2-3 hours each day to get through all levels. Sometimes, the quiz requires that you search something in Google, or you have a satellite image and you need to figure out where it is. Very impressive, amazing game!

People who like quiz like also to follow howto instructions to get

The full Map Stack up and running

I am fascinated by the Open Source technology behind OpenStreetMap, which I believe will soon be succesful as Wikipedia is.

After importing the dump of Switzerland in the old Gentoo server, I showed the result to my father and he gave me another piece of iron to reach the next level of this particular game: it is an IBM with 3.2 GHZ and 1 GB of RAM. I installed Ubuntu Jaunty (9.04) on the server and repeated the PostgreSQL and mapnik install following these howto instructions made by Johnny Dobbins. This tutorial additionally explains how to install the WMS server called ogcserver and how to put a cache in front of it, so that already computed tiles do not need to be recomputed but can just be served directly from disk (or from memcache or even from Amazon S3).

Just some remarks on how the job was done:

Choosing a bounding box

the server has 74 GB of disk, so based on this specs I decided to import Europe and part of Asia till longitude of Moskau and not the whole planet. For the whole planet you probably need at least 200 GB of disk.

To be precise I chose this rectangle with coordinates taken from an old fashioned Atlas: Top left corner: 75 N, 35 W Bottom right corner: 20N 60 E

This command extracted from the whole planet file the bounding box and created a new dump called eurasia.osm.bz2. The decompression and compression is done with bzcat and bzip2 piped together.

bzcat ../../planet-latest.osm.bz2 | ./bin/osmosis --read-xml
enableDateParsing=no file=/dev/stdin --bounding-box left=-35
bottom=20 right=60 top=75 --write-xml file=- | bzip2 >
../../eurasia.osm.bz2

The execution lasted for about 14 hours. Out of the 7.4 GB of planet-latest.osm.bz2, about 2.2 GB of data where extracted for eurasia.osm.bz2. After the import with osm2pgsql in Postgres database, the bounding box takes about 40 GB of disk space.

Minor remarks on the howto of Johnny

I did not find the lines in cgiserver.py, so I left this step out.

For the file wms.py: you need to completely replace the existing file with the lines shown in the howto.

Setup of ogcserver

When browsing to http://localhost:8080, I got an error. Looking at /var/log/apache2/error.log,

I noticed this error:

IOError: sys.stdin access restricted by mod_wsgi           
                      

I then added at the bottom of /etc/apache2/sites-available/default outside the VirtualHost section the following two lines:

WSGIRestrictStdout Off
WSGIRestrictStdin Off

Tilecache: Seeding the cache

After setting everything up, pieces of the map started appearing. However, often the server got overloaded, if it had to compute tiles which where full of features (streets and rivers). Especially the tile with Germany never appeared as it was too feature rich. Eventually, the server hang up when even the swap cache got full.

The solution to this performance problem was to seed the cache. I chose a point in the center of Europe (46 N, 10 E) and a radius of 30 degrees.

I then issued in the directory ogcserver/tilecache-2.10/ the following command:

./tilecache_seed.py basic
46,10,30
[press Control D on the keyboard]

and I let compute map tiles for about 48 hours.

The result

Here it is :-). Happy browsing, press twice the plus button first, to reach the correct zoom level. The speed in serving tiles might vary, as I have an ADSL and use dynamic DNS...

Your own Openstreet map tile server on Gentoo

I wrote down some steps that differ from the excellent tutorials here and here, because my installation is performed on Gentoo instead of Ubuntu: of course, this is working now as for December 2009, but an emerge --sync in the future might solve some of these problematic steps (maybe someone more knowledgeable than me will read this tutorial and fix some ebuilds :-).

Step: Subversion and Java

These one were easy and you probably figured out faster than me: emerge -av subversion
emerge -av sun-jdk


Step: Installing Postgresql with Postigs spatial extensions

osm2pgsql does not work with Postgresql 8.1 which is marked stable in Gentoo. The reason is that Postgresql 8.1.11 does not know about the command 'DROP TABLE IF EXISTS' which is used in oms2pgsql. Defining a stored procedure that does the same and modifying the source code of osm2pgsql did not work for me.

Therefore I chose another way, which goes as follows: you should add at the end of /root/.bashrc the following alias:

alias aemerge='ACCEPT_KEYWORDS="~x86" emerge '
source /root/.bashrc will load this setting for the first time. The setting is kept after, as .bashrc is read at every login. From now on, you can use "aemerge" to emerge unstable packages instead of "emerge".

Then, you can install an unstable Postgresql with
aemerge -av postgresql


This will install a Postgresql 8.2.14 which is fine for our purposes.

Install also Postgis:
aemerge -av postgis
Postgis-1.4.0 is then installed.

Configure the database postgis extensions not by using emerge --config as suggested at the end of emerge, but use the instructions provided in this tutorial. Remember to follow the instructions as normal user and not as superuser (a part of the inital step of setting up the database).

As noted in the previous comment, lwpostgresql.sql does not exist in postgis anymore, it was renamed in postgis.sql, you should therefore use
psql -d gis -f /usr/share/postgresql/contrib/postgis.sql


Step: Installing mapnik
For mapnik I had problems, it did not compile from source as described in the tutorial, it was failing when compiling the postgis plugin for linking reasons against the library libpq.la, though the library was present on the proposed path.

I did the following trick:

USE="postgresql" aemerge -av mapnik


emerged and installed a mapnik with all dependencies, which however was not able to recognize the postgis extensions on the 'gis' database.

In fact, when running ./z0_generate_tiles.py, mapnik was failing with:

Could not create datasource. No plugin found for type 'postgis' (encountered during parsing of layer 'leisure') when connecting to the imported database.


Then I did the following: I unmerged the unstable libpq library (libpq is a library used by postgresql used as connection layer.
emerge --unmerge libpq
I unmerged mapnik without its dependencies with
emerge --unmerge mapnik
I installed the stable libpq library with:
emerge -av libpq
Then I installed mapnik from source with the following steps
mkdir src
cd src
svn co http://svn.mapnik.org/trunk/ mapnik
cd mapnik
scons/scons.py -c install
scons/scons.py PGSQL_LIBS=/usr/lib/postgresql/ PGSQL_INCLUDES=/usr/include/postgresql/
sudo scons/scons.py install PGSQL_LIBS=/usr/lib/postgresql/ PGSQL_INCLUDES=/usr/include/postgresql/
ldconfig


Therefore: postgresql is compiled against an unstable version of libpq, while mapnik needs a stable one to compile. Of course, postgresql will survive the restart with
/etc/init.d/postgresql restart
:-)

Have fun with your maps! Import the planet on your favourite Gentoo box!

Coffee Break Planner

To increase the number of visitors to our webserver, I finally found a killer application. I developed it as a Google Gadget and is called the Coffee Break Planner. This gadget helps you to meet with your friends at the right time for a tasteful coffee... It also increases the overall performance of your company, as in coffee breaks most of the time people speak about work anyway :-)

Again, the gadget is only an xml envelope, while PHP and mySQL do the hard work.

I created this gadget to upload files to my webserver as ftp is firewalled in the company I am working for. I prepared it so that other people can install on their webserver as well, if they read the Readme on the gadget :-)

To work on the webserver I use this service, which costed me 15 euro for one year. It is a Unix shell via HTTPS that can be opened with a normal browser. Tunneling with httptunnel or corkscrew or any other trick did not work for me... Too stupid to break out without commercial support, ehm!

Joomla

Since beginning of the year I manage the local boy scout homepage with Joomla and I am very happy with this solution, last but not least released as Open Source.

Android emulator v2.0

I am experimenting with Eclipse, Android v2.0 and a tutorial a friend did... But I still do not have meaningful results. Some Java exception crashes the small application and the emulator does not work behind the proxy, even if the -http-proxy option is set in the launch parameters. Notice that the mysql trick works only with Android 1.6. Probably the proxy filters also on the browser identification string... and the emulator does not mimic a Mozilla or IE as identification... And the proxy is difficult to overcome...