ConfigureO2S

MOST IMPORTANT

After checking out O2S, first add/modify the PYTHONPATH environment variable (best done in your startup dotfile). For bash users:

EXPORT PYTHONPATH=[path to your o2s]/lang-support/python/

For tcsh:

setenv PYTHONPATH [path to your o2s]/lang-support/python/

Windows users:

Right-click on My Computer, select Properties. Select the Advanced tab and click the Environment Variables button. Make a new System Variable:

 Variable name: PYTHONPATH
 Variable value: C:/home/username/o2s/lang-support/python/

The rest (as follows) is optional.

---

Upon startup, O2S checks various places for configuration variables. Specifying configuration variables is completely optional! If these variables aren't specified, the system sets them to reasonable default values.

TODO: After implementing local registry detection, update documentation to 
reflect new "Registry Address" semantics.

Contents

1. O2S Configuration Variables
2. Variable Resolution order
   1. Command Line Switches
   2. Environment Variables
   3. ~/.o2s dotfile
   4. /etc/o2s sitewide configuration file
3. Extending O2S Configuration Variables

O2S Configuration Variables

• Registry Address: Specifies the registry address.

  • Default: o2s.csail.mit.edu:7887

• User (name): Specifies the user.

  • Default: The current user.

• Location: Specifies the Entity's location.

  • Default: The current user's office, e.g., Steve's Office

• Client Type: Specifies the Operating System/Platform.

  • Default: The detected platform.

• Logging: Specifies how much debugging spew to output.

  Allowed values, with increasing verbosity: critical (same as error), warning, info, debug, debug1, debug2, debug3.

  • Default: warning

Once O2S is running, the value of these variables are available inside system.o2s_globals.

Variable Resolution order

There are several methods for specifying the configuration variables; below is the precedence for these methods, in descending order. Once a variable is specified in any of the methods, no further resolution is done.

1. Command Line Switches

2. Environment Variables

3. ~/.o2s (personal configuration file)

4. /etc/o2s (site-wide configuration file)

Command Line Switches

Command line switches override all variables set by other methods; the switches are generally useful for overriding variables from their default values (or those specified in dotfiles). The switches are:

• --o2s-registry-address : Registry Address

  Example: python myO2Sfile.py --o2s-registry-address=elsie.csail.mit.edu:7887

• --o2s-user : User name

  Example: python myO2Sfile.py --o2s-user=Steve 

• --o2s-location : Location

  Example: python myO2Sfile.py --o2s-location="32-G786"

• --o2s-client-type : Device Type/Platform

  Example: python myO2Sfile.py --o2s-client-type=iPAQ 

• --o2s-logging : Logging

  Example: python myO2Sfile.py --o2s-logging=info

You may specify as few or as many switches as necessary:

% python myO2Sfile.py --o2s-registry-address=elsie.csail.mit.edu:7887 --o2s-user=Steve --o2s-location="32-G786" --o2s-logging=info

Environment Variables

Environment variables are checked following the command-lind switches. Environment variables are typically useful for overriding certain variables temporarily during a session. They are:

• O2S_REGISTRY_ADDRESS : Registry Address

• O2S_USER : User

• O2S_LOCATION : User's Location

• O2S_CLIENT_TYPE : Device Type/Platform

• O2S_LOGGING : Logging Verbosity Level

Here is an example for setting environment variables:

bash% export O2S_REGISTRY_ADDRESS=elsie.csail.mit.edu:7887
bash% export O2S_USER=Steve
bash% export O2S_LOCATION=32-G786
bash% export O2S_CLIENT_TYPE=iPAQ
bash% export O2S_LOGGING=info

~/.o2s dotfile

The ~/.o2s configuration file is useful for storing more permanent settings. The file follows the standard Windows INI format.

• O2S_REGISTRY_ADDRESS or REGISTRY_ADDRESS: Registry Address

• O2S_USER or USER : User

• O2S_LOCATION or LOCATION : User's Location

• O2S_CLIENT_TYPE or CLIENT_TYPE : Device Type/Platform

• O2S_LOGGING or LOGGING : Logging Verbosity Level

Here's an example ~/.o2s file:

# this is a comment
[DEFAULT]
REGISTRY_ADDRESS = elsie.csail.mit.edu:7887
USER = Steve
LOCATION = 32-G786
DEVICE_TYPE = iPAQ
LOGGING = info

Note: it is important that these variables fall under the [default] heading. (Not: [defaultS])

/etc/o2s sitewide configuration file

The /etc/o2s file is a site-wide configuration file for storing system defaults. The file format is exactly the same as the ~/.o2s file. Here's an example /etc/o2s file that specifies the location for the host:

# this is a comment
[DEFAULT] 
LOCATION = 32-G786

Extending O2S Configuration Variables

To add more O2S configuration variables to the mix, modify system.init.o2s_init.make_settings_parser().