Up: PICA manual
PICA relies on several important concepts:
- PICA Server
- Host that stores the source objects known to PICA.
- PICA Client
- Any host with a way to connect to it (usually SSH).
- Objects are ``entities'' we want installed in our servers.
One entity, once installed, can be different depending on the server it is to
be installed in. For this purpose, objects are represented with files which
can contain special directives, interpreted by the Perl PreProcessor (one of
the PICA components). There are two types of entities (also called
``distribution files'', or ``distributed files''): files and alarms.
- Regular files to be installed in a given path of the remote
- Alarms are executable files, to be installed in special
directories which PICA takes care of. Alarms are executed from time to time,
and they are supposed to produce some output if there is something to notify.
Furthermore, alarms can have dependencies, which are files that have to
be (re)installed if the alarm depending on them is (re)installed.
- Your (theoretically remote) machines. You are supposed to have
your configuration files in one host, to copy them in a bunch of machines.
These machines are the ``hosts''.
- PICA recognized two types of groups: host groups and object
groups. Groups are used to organize and easily manage large collections of
objects. More on groups later.
- Attributes are object properties. There are mandatory
and optional attributes, depending on the type of object (file or alarm).
- You can use ``variables'' that can be referred to in the
preprocessor and the files to be distributed. Sometimes we use the adjective
``local'' to refer to object variables, and ``group'' to refer to those
of...you get the idea.
- They are variables defined as command line arguments
(more on that later).
- Local directories
- Directories needed by PICA to find executables or
source objects (directories in the PICA server).
- Remote directories
- Directories where PICA installs objects
(directories in the PICA client).
Up: PICA manual
Esteban Manchado Velázquez