diff options
| -rw-r--r-- | AUTHORS | 1 | ||||
| -rw-r--r-- | PLUGINS | 48 | ||||
| -rw-r--r-- | tasker/plugins.py | 8 |
3 files changed, 54 insertions, 3 deletions
@@ -1,2 +1,3 @@ Martin Sivak <msivak@redhat.com> +Joel Andres Granadoso <jgranados at redhat dot com> @@ -9,11 +9,47 @@ All plugins belong to configured plugin directory. Recognized suffixes are: Plugin Model ------------ -Describe plugin model TODO. + +The FirstAidKit plugin is modeled using graph theory. Common stuff for plugins ------------------------ +The building blocks of the plugins are functions and flows. A function +is a certain action that is taken inside the plugin. This action is more +or less independant from the rest of the plugin actions. Things like fix, +backup, restore... qualify as actions/functions. This does not mean that +functions do not relate to each other. This is where the flow comes into +play. + +A flow is the organization of functions in a directional graph that defines +the "flow" of functions. Understand flow here as the order in which each +function is executed. This order/flow is specified using the function +names and their return codes. All this is contained within a dictionary. +Lets ilustrate with an example: + +1. Consider the following flow: + start->fix->end +2. The dictionary that expresses this flow: + dict = { start:fix, fix:end} + +Lets ilustrate a more complex example: +1. Consider the following flow: + start->diagnose->end + `>fix->end + This flow has a conditional after the diagnose function. If diagnose + results in a corrupt state of the system, then the plugin proceeds + with fix. If all is good in the system, then the flow end. +2. The dictionary that expresses this flow: + dict = {start:diagnose, diagnose:{"goodSys":end, "badSys":fix}, fix:end} + note that the next step in the diagnose case is defined buy whatever + diagnose returned. + +The idea is to define individual set of activities in the functions. And +to put these activities together with the flows. As mentioned before +the activities are just functions. The flow on the other hand is a dict +that defines the next function to execute given the return value of the +current function. Each plugin exports some steps. The mandatory ones are @@ -21,7 +57,6 @@ Each plugin exports some steps. The mandatory ones are - backup -- backup everything we could touch in this plugin - diagnose -- get info about the investigated system and determine where the problems are -- describe -- describe the findings from diagnose step - fix -- autofix the errors from diagnose step - restore -- restore system from backup - destroy -- destroy the plugin, cleanup @@ -54,12 +89,21 @@ __iter__() and next() -- iterator protocol, works in the same way as actions() -- returns list of available step names call(step) -- calls one specific step identified by name info() -- returns tuple of strings defined as (name of plugin, version, author) +changeFlow() -- allows the caller to change to some other flow defined in the + plugin. +getFlows() -- Returns all the possible flows that the plugin suports. + And of course the steps itself. They are defined as methods with the same names as used in actions(). Return Class ------------ +To make the model work when a function returns it has to return the same type of +object. At the same time this object must have the possibility to change and +specify the return code. Moreover, when the developer creates new return classes +he/she can put important return stuff into the class. If the function is to +return a tuple, dictionary... it can always be housed inside the class. Arbitrary executable modules ---------------------------- diff --git a/tasker/plugins.py b/tasker/plugins.py index 31c45e0..9ce8db4 100644 --- a/tasker/plugins.py +++ b/tasker/plugins.py @@ -30,6 +30,12 @@ from cStringIO import StringIO class Plugin(object): def __init__(self): # + # Some information vars. + # + self.name = "Plugin" + self.version = "0.0.0" + self.author = "nobody" + # # The initial and final states are here to give more flexibilty to the # Development process. All flows will start and end with these two # Variables. @@ -90,7 +96,7 @@ class Plugin(object): def info(self): """Returns tuple (Plugin name, Plugin version, Plugin author)""" - return ("Plugin", "", "") + return (self.name, self.version, self.author) # # The flow functions. |