Plugins/Rules

  1. The Rules Plugin
    1. Usage of Groups in Rules
    2. Tag Attributes in Rules
      1. Rules Tag
      2. Rules Group Tag
      3. Package Tag
      4. Permissions Tag
      5. Action Tag
      6. Service Tag
      7. Directory Tag
      8. SymLink Tag
      9. Client Tag
      10. Path Tag
    3. Rules Directory

The Rules Plugin

The Rules plugin resolves the following Abstract Configuration Entities:

  • Service
  • Directory
  • SymLink
  • Package
  • Path
  • Permissions
  • Action

to literal configuration entries suitable for the client drivers to consume.

For an entity specification to be included in the Literal configuration the name attribute from an Abstract Entity Tag (from Base or Bundler) must match the name attribute of an Entity tag in Rules, along with the appropriate group associations of course.

Each file in the Rules directory has a priority. This allows the same Entities to be served by multiple files. The priorities can be used to break ties in the case that multiple files serve data for the same Entity.

Usage of Groups in Rules

Groups are used by the Rules plugin, along with host metadata, for selecting the Configuration Entity entries to include in the clients literal configuration. They can be thought of as: 

if client is a member of group1 then
    assign to literal config

Nested groups are conjunctive (logical and). 

if client is a member of group1 and group2 then
    assign to literal config

Group membership may be negated.

Tag Attributes in Rules

Rules Tag

The Rules Tag may have the following attributes:

Name Description Values
priority Sets the priority for Rules in this Rules list.The higher value wins. String

Rules Group Tag

The Rules Group Tag may have the following attributes:

Name Description Values
name Group Name String
negate Negate group membership (is not a member of) (True|False)

Package Tag

The Package Tag may have the following attributes:

Name Description Values
name Package Name String
version Package Version orversion='noverify' to not do version checking in the Yum driver only (temporary work a round). String
file Package file name. Several other attributes (name, version) can be automatically defined based on regular expressions defined in the Pkgmgr plugin. String
simplefile Package file name. No name parsing is performed, so no extra fields get set String
verify verify='false' - do not do package verification String
reloc RPM relocation path. String
multiarch Comma separated list of the architectures of this package that should be installed. String
srcs Filename creation rules for multiarch packages. String
type Package type. (rpm, yum, apt,sysv,blast) String

Permissions Tag

The Permissions tag is

Name Description Values
name Name of the file. String
perms Permissions of the file.
owner Owner of the file.
group Group of the file.

Action Tag

See Actions

Service Tag

The Service tag is

Name Description Values
name Service Name String
status Should the service be on or off. (on|off)
restart Service command for restart (default:restart) String
type Driver to use on the client to manage this service. (chkconfig|deb|rc-update|smf)
sequence Order for service startup (debian services only) integer

Directory Tag

The Directory tag is

Name Description Values
name Directory Name String
perms Permissions of the directory. String
owner Owner of the directory String
group Group Owner of the directory String
prune prune unspecified entries from the Directory true|false

SymLink Tag

The SymLink tag is

Name Description Values
name Name of the symlink. String
to File to link to String

Client Tag

The Client Tag is used in Rules for selecting the package entries to include in the clients literal configuration. Its function is similar to the Group tag in this context. It can be thought of as: 

if client is name then
    assign to literal config

The Client Tag may have the following attributes:

Name Description Values
name Client Name String
negate Negate client selection (if not client name) (True|False)

Path Tag

The Path tag is

Name Description Values
name Name of the file String
type Type of file nonexistent

Rules Directory

The Rules/ directory keeps the XML files that define what rules are available for a host. All the files in the directory are processed.

The names of the XML files have no special meaning to Bcfg2; they are simply named so it's easy for the administrator to know what the contents hold. All Rules could be kept in a single file if so desired. Bcfg2 simply uses the Groups in the files and priorities to determine how to assign Rules to a host's literal configuration. 

<Rules priority="0">
    <Directory group="root" name="/autonfs" owner="root" perms="0755"/>
    <Directory group="utmp" name="/var/run/screen" owner="root" perms="0775"/>
    <Directory group="root" name="/autonfs/stage" owner="root" perms="0755"/>
    <Directory group="root" name="/exports" owner="root" perms="0755"/>
    <Directory name="/etc/condor" owner="root" group="root" perms="0755"/>
    <Directory name="/logs" group="wwwtrans" owner="root" perms="0775"/>
    <Directory name="/mnt" group="root" owner="root" perms="0755"/>
    <Directory name="/my" owner="root" group="root" perms="0755"/>
    <Directory name="/my/bin" owner="root" group="root" perms="0755"/>
    <Directory name="/nfs" owner="root" group="root" perms="0755"/>
    <Directory name="/sandbox" perms="0777" owner="root" group="root"/> 
    <Directory name="/software" group="root" owner="root" perms="0755"/>
    <Permissions perms="0555" group="audio" owner="root" name="/dev/dsp"/>
    <Permissions perms="0555" group="audio" owner="root" name="/dev/mixer"/>
    <SymLink name="/bin/whatami" to="/mcs/adm/bin/whatami"/>
    <SymLink name="/chibahomes" to="/nfs/chiba-homefarm"/>
    <SymLink name="/home" to="/nfs/mcs-homefarm"/>
    <SymLink name="/homes" to="/home"/>
    <SymLink name="/mcs" to="/nfs/mcs"/>
    <SymLink name="/my/bin/bash" to="/bin/bash"/>
    <SymLink name="/my/bin/tcsh" to="/bin/tcsh"/>
    <SymLink name="/my/bin/zsh" to="/bin/zsh"/>
    <SymLink name="/software/common" to="/nfs/software-common"/>
    <SymLink name="/software/linux" to="/nfs/software-linux"/>
    <SymLink name="/software/linux-debian_sarge" to="/nfs/linux-debian_sarge"/>
    <SymLink name="/usr/bin/passwd" to="/usr/bin/yppasswd"/>
    <SymLink name="/usr/bin/yppasswd" to="/mcs/bin/passwd"/>
    <SymLink name="/usr/lib/libgd.so.1.8" to="/usr/lib/libgd.so.1.8.4"/>
    <SymLink name="/usr/lib/libtermcap.so.2" to="/usr/lib/libtermcap.so"/>
    <SymLink name="/usr/local/bin/perl" to="/usr/bin/perl"/>
    <SymLink name="/usr/local/bin/perl5" to="/usr/bin/perl"/>
    <SymLink name="/usr/local/bin/tcsh" to="/bin/tcsh"/>
    <Service name='ntpd' status='on' type='chkconfig'/>
    <Service name='haldaemon' status='on' type='chkconfig'/>
    <Service name='messagebus' status='on' type='chkconfig'/>
    <Service name='netfs' status='on' type='chkconfig'/>
    <Service name='network' status='on' type='chkconfig'/>
    <Service name='rawdevices' status='on' type='chkconfig'/>
    <Service name='sshd' status='on' type='chkconfig'/>
    <Service name='syslog' status='on' type='chkconfig'/>
    <Service name='vmware-tools' status='on' type='chkconfig'/>
</Rules>