Using CA AppLogic® › Appliance Developer Guide › Appliance Kit › Appliance Boundary › Interior Boundary › Automatic Configuration File Update

Automatic Configuration File Update

In many cases, the appliance properties correspond directly to strings that need to be inserted into an appliance-specific configuration file. In such cases, rather than writing code to read one of the APK-provided property files (described above) and generate the appropriate configuration files on each boot, it is possible to instruct APK to apply the property values directly to the configuration files. This can be done in all cases where the following conditions are met:

• The appliance has a writable disk volume (that is, this method is not suitable for an appliance whose volumes are all read-only).
• The property value needs to be simply inserted into the configuration file.
• The configuration file is a text file.
• The configuration file format allows for adding comments to it, and the programs using it either do not modify the file, or re-write it keeping the comments intact.

To set up APK to do automatic config file updates on boot:

• The configuration files are instrumented with special comments that specify exactly where the property values are to be inserted. The instrumentation syntax can be found here:
  http://doc.3tera.com/AppLogic35/en/PropMarkSyntax.html
• The list of files to be updated is configured in the APK_CONFIG_FILES setting in the applogic_init configuration file.