Flux multi-user server

The educational technology and digital learning wiki
Jump to navigation Jump to search

Draft

Definition

Flux multi-user server (alis Hydra) is Open Virtual Worlds Web Server made by Media Machines. Currently in alpha/early beta - 18:34, 6 July 2007 (MEST)

Installation

Daniel K. Schneider on his personal Linux Desktop (Ubuntu 6.10). Disclaimer: I am not a programmer nor a sysadmin. Also, I use root to do command-line installations (can't get myself to type sudo in repetition).

Downlods

  1. Get the Hawk Network Library version 1.7 by Phil Frisbie (LGPL). You can find it in the downloads section.
  2. Get Hydra, Flux Multi-User
  3. Get MySQL development libraries
  4. Also install Flux Player 2.1 if you don't have it already.

Preparation of installation

MySQL
  • Install MySQL and the development libararies !
  • Use Synaptic Package Manger or apt-get and install these

I took: 

mysql-server
libmysqlclient15-dev

If don't want to type command-lines to mysql, you also may want to install a mysql administration client. I tried (but then only used it to change the root password of the mysql server). 

mysqladmin

This tool then will show up under Applications/Systems tools. First time you connect you can use 'root' without password.

Then, open a terminal and become root: 

su
Hydras (files)

Currently (July 2007) you have to compile Hydras and HawkNL it yourself.

  • unzip into a folder, e.g. I used
/usr/local/flux/hydra
Modify some source code
  • I suggest to make a change to scenemodel.c (else you will have to use database, user and password for MySQL... Change line 51 from:
(&hydra_db, "localhost", "user", "password", "database", 0, NULL, 0) != NULL);

to: 

 (&hydra_db, "localhost", "hydrausr", "SECRET", "hydra", 0, NULL, 0) != NULL);
  • Edit hydras.c, i.e. replace
char *url = "http://worlds.webers.org/content/testbed/";

by something of your own

HawkNL
  • Put it in a folder named "HawkNL" at the same level as the folder containing the Hydra sources. E.g. I used
/usr/local/flux/HawkNL

 unzip HawkNL17b1src.zip [-d "flux directory"]
 cd "flux directory"
 ln -s HawkNL1.70 HawkNL
Result is something like this
/usr/local/flux
lrwxrwxrwx  1 root root   10 2007-07-06 15:28 HawkNL -> HawkNL1.70
drwxr-xr-x  7 root root 4096 2007-07-06 15:27 HawkNL1.70
drwxr-xr-x  2 root root 4096 2007-07-06 15:40 hydra
drwxr-xr-x  2 root root 4096 2007-07-06 15:39 src

Compilation

HawNL
 cd HawkNL
 make -f makefile.linux
 make -f makefile.linux install

It will also copy the libraries in /usr/local/lib and header to /usr/local/include/nl.h

Hydras
  • On Windows, load the hydras.sln or hydrac.sln solution files into MSVC 2003 or later (not tested)
  • On Linux (I used Ubuntu) run make on the Makefile with gcc installed.
cd hydra
make

Result: 

gcc -I/usr/include/mysql -DUSE_MYSQL -c scenemodel.c
gcc -I/usr/include/mysql -DUSE_MYSQL -c netcontroller.c
gcc -c netview.c
gcc -c -ggdb swamp.c
gcc -o hydras -pthread hydras.o clients.o scenemodel.o netcontroller.o  netview.o swamp.o ../HawkNL/src/libNL.a -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient
gcc -c -ggdb hydrac.c
gcc -o hydrac -pthread hydrac.o swamp.o ../HawkNL/src/libNL.a
hydrac.o: In function `printErrorExit':
/usr/local/flux/hydra/hydrac.c:76: warning: the `gets' function is dangerous and should not be used.
make: *** No rule to make target `hydrabot', needed by `all'.  Stop.

This doesn't seem to be harmful (for the moment) since hydras (the server) is built.

MySQL database

Create a hydra database and a user (same as in scenemodel.c)

I used the command line since I couldn't figure out how to use the GUI ;) 

mysql -p
  • You have to create a hydra_db databse called hydra
mysql> create database hydra;
  • Then create the user called hydrausr (change secret of course)
mysql> create user hydrausr identified by 'secret';
  • Then give it rights to the hydra database
mysql > GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON hydra.* TO 'hydrausr'@'localhost';
  • Then reload the privileges
mysql > flush privileges;
Create a User table

This is needed for avatars, else you get something like: 

Client connected with yourid=1, mytoken=/MM-6-12345678, uid=6
SELECT login_name,avatar FROM users WHERE uid=6
wrote 61 bytes to 1
Segmentation fault (core dumped)

So you go: 

mysql -p
use hydra

Copy/paste this: 

CREATE TABLE `users` (
`login_name` varchar(32) default NULL,
`password_hash` varchar(128) default NULL,
`uid` int(10) unsigned NOT NULL auto_increment,
`avatar` varchar(128) default NULL,
`email` varchar(255) default NULL,
`iconurl` varchar(255) default '/users/media/defaulticon.jpg',
terms smallint unsigned default 0, /* signifies which terms user agreed to, should  always be > 0 */
mailings smallint unsigned default 0, /* signifies the level of mailings user agreed to,  0 is only essential */
PRIMARY KEY (`uid`)
);

To check it: 

mysqlshow hydra -p
Enter password: 
Database: hydra
+--------+
| Tables |
+--------+
| users  |
+--------+

mysqlshow hydra users -p
.....

Run it to test if it may work

Type: hypdras 

./hydras

You may see: 

port is 13214
url is http://tecfa.unige.ch/guides/x3d/ex/hydra/testbed.html
connected to database
Listening on 13214

Note: if you didn't edit the *.c files as told above, you will get 

 url is http://worlds.webers.org/content/testbed/

From another terminal you also may launch a text client. 

./hydrac -d

You may see: 

read 4 bytes, messlen is 6
read 6 bytes, messlen is 6
hello yourid=0, mytoken=NA

... though I can't figure out how one could use this.

Run it with your own stuff

To test, get the Flux Multi-user test files from media machines and dezip on some webserver.

Then edit files localplane.x3d and testbed.x3d etc. and change from: 

 url="'swmp://localhost:13214/MM-6-12345678'"/>

to the URL of your Hydra server (not the webserver !)

The try with a Flux Player. E.g. enter a URL like 

http://tecfa.unige.ch/guides/x3d/ex/hydra/localplane.html
http://tecfa.unige.ch/guides/x3d/ex/hydra/testbed.html

Note: The hydra URL runs on my desktop and will be mostly down ... So don't bet on the files / server I installed.

If you correctly created the MySQL users table you'll see something like: 

./hydras -d
port is 13214
url is http://tecfa.unige.ch/guides/x3d/ex/hydra/testbed.html
connected to database
Listening on 13214
Client connected from 129.194.112.101:1032 on socket 1
read 18 bytes from 1
wrote 6 bytes to 1
Client connected with yourid=1, mytoken=/MM-6-12345678, uid=6
SELECT login_name,avatar FROM users WHERE uid=6
wrote 61 bytes to 1
read 35 bytes from 1
read 35 bytes from 1
read 35 bytes from 1
.....



Links

Mediamachines


Help for installation
Retrieved from "https://edutechwiki.unige.ch/mediawiki/index.php?title=Flux_multi-user_server&oldid=12927"