Database models

http://hostinfo.googlecode.com/files/DB_Schema.png

Generic Details

Almost all classes have some shared attributes:

  • origin - a string representing the origin of the data, generally the user who made the change
  • createdate - when the data was created for the first time. Automatically populated by Django
  • modifieddate - when the data was last modified. Automatically populated by Django
  • docpage - a link to documentation about this item; currently unused
  • history - a link to previous versions to allow audit and rollback

All tables/models have an implicit id field which is the primary key for the table. Foreign Key relationships are tied to this id. This also means that if you change the name of a host it is only changing the name associated with an id, not creating a new host instance with a new name.

Host

This a base class storing core details about the host of which there is only really the hostname. Everything else is in other models and linked to this one.

Attributes

  • hostname - the name of the host

HostAlias

Any host can have multiple aliases. An alias can only point to a single host. Any reference to an alias should be the same as if you referred to the real name itself.

Attributes

  • hostid - Foreign Key to Host
  • alias - The alias itself

AllowedKey

This is where the definitions of the different keys are kept

Attributes

  • key - the name of the key

  • validtype - what the contents of the value should be interpreted as

    • single
    • list
    • date

  • desc - a short description of the meaning of the key

  • restrictedFlag - a boolean indicating that this key can only take on specific values

  • readonlyFlag - a boolean indicating that this key is read-only be agreement - it just means you have to say please when changing it. This is ‘enforced’ only at the user interface layer.

  • auditFlag - a boolean which if set (the default) will track changes to related values.

KeyValue

This is the table where the values that make up hostinfo are stored.

Attributes

  • hostid - Foreign Key to Host
  • keyid - Foreign Key to !AllowedKey
  • value - the value

UndoLog

The undo log is a list of commands required to reverse actions. It is accessed by the user with [hostinfo_undolog]

Attributes

  • user - Who made the change
  • actiondate - When did they make they change
  • action - What action is required to undo their change

RestrictedValue

This is where the list of acceptable values are kept for the keys that have a restricted list of values.

Attributes

  • keyid - Foreign Key to !AllowedKey
  • value - An acceptable value for that key