.. -*- mode: rst -*-
.. _server-plugins-generators-pkgmgr:
======
Pkgmgr
======
.. note::
See [wiki:ClientTools/RPMng#PackageTagNewStyleandAttributes
RPMng#PackageTagNewStyleandAttributes].''' The way of showing the
architecture of the RPM has changed. The new way is "arch". The
old way is "multiarch". '''This document needs to be updated and
include version of Bcfg2 where change took place.'''
The Pkgmgr plugin resolves the Abstract Configuration Entity "Package"
to a package specification that the client can use to detect, verify
and install the specified package.
For a package specification to be included in the Literal configuration
the name attribute from an Abstract Package Tag (from Base or Bundler)
must match the name attribute of a Package tag in Pkgmgr, along with
the appropriate group associations of course.
Each file in the Pkgmgr directory has a priority. This allows the
same package 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 package.
Usage of Groups in Pkgmgr
=========================
Groups are used by the Pkgmgr plugin, along with host metadata,
for selecting the package 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 Pkgmgr
========================
PackageList Tag
---------------
The PackageList Tag may have the following attributes:
+-----------+-----------------------------------------------+----------------+
| Name | Description | Values |
+===========+===============================================+================+
| priority | Sets the priority for packages in the package | Integer |
| | list. The higher value wins. | |
+-----------+-----------------------------------------------+----------------+
| type | Package type that applies to all packages in | deb|rpm|blast| |
| | the list. This value is inherited by all | encap|sysv| |
| | packages without an explicit type attribute. | portage|yum |
+-----------+-----------------------------------------------+----------------+
| uri | URI to prepend to filename sto fetch packages | String |
| | in this list. | |
+-----------+-----------------------------------------------+----------------+
| multiarch | Comma-separated list of architectures that | String |
| | apply to all packages in this list. Inherited | |
| | by all package entries in the file that does | |
| | not have this attribute explicitly. | |
+-----------+-----------------------------------------------+----------------+
| srcs | To be used with multiarch support. Inherited | String |
| | by all Package entries without this attribute | |
+-----------+-----------------------------------------------+----------------+
Pkgmgr Group Tag
----------------
The Pkgmgr 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, set to ``auto`` to install | String |
| | the latest version in the client's cache, or | |
| | ``any`` to verify that any version of the | |
| | package is installed on the client | |
+------------+----------------------------------------------+------------+
| file | Package file name. Several other attributes | String |
| | (name, version) can be automatically defined | |
| | based on regular expressions defined in the | |
| | Pkgmgr plugin. | |
+------------+----------------------------------------------+------------+
| simplefile | Package file name. No name parsing is | String |
| | performed, so no extra fields get set | |
+------------+----------------------------------------------+------------+
| verify | Whether package verification should be done | True|False |
+------------+----------------------------------------------+------------+
| multiarch | Comma-separated list of the architectures of | String |
| | this package that should be installed. | |
| | (Temporary work-around) | |
+------------+----------------------------------------------+------------+
| srcs | File name creation rules for multiarch | String |
| | packages. (Temporary work-around) | |
+------------+----------------------------------------------+------------+
| type | Package type (rpm, yum, apt, sysv, blast) | String |
+------------+----------------------------------------------+------------+
Client Tag
----------
The Client Tag is used in a PackageList 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 |
+--------+----------------------------------------------+------------+
Pkgmgr Directory
================
The Pkgmgr/ directory keeps the XML files that define what packages
are available for a host or image and where to find those packages.
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 Packages 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 Packages to a host's literal configuration.
Listed detailed below is one possible structure for the Pkgmgr directory.
The files are structured to contain particular portions of distribution
repositories.
The files in the directory are::
$ ls Pkgmgr/
centos-4-noarch-updates.xml
centos-4-x86_64-updates.xml
centos-4-x86_64.xml
backup.example.com.xml
fedora-core-4-noarch-updates.xml
fedora-core-4-x86-updates.xml
fedora-core-4-x86.xml
rhel-as-4-noarch-updates.xml
rhel-as-4-x86-updates.xml
rhel-as-4-x86.xml
rhel-es-4-noarch-updates.xml
rhel-es-4-x86-updates.xml
rhel-es-4-x86.xml
rhel-ws-4-noarch-udpates.xml
rhel-ws-4-x86_64-updates.xml
rhel-ws-4-x86_64.xml
rhel-ws-4-x86-updates.xml
rhel-ws-4-x86.xml
As can be seen the file names have been selected to indicate what the
contents are and have been split by Vendor, product and repository area.
A partial listing of the centos-4-x86_64.xml is below
.. code-block:: xml
$ cat centos-4-x86_64.xml
...
.. code-block:: xml
$ cat centos-4-x86_64-updates.xml
...
Here it can be seen that the data is encapsulated in a !PackageList Tag
which describes the URI of the files described, the type of package,
and the priority of the files in this list.
The priority is used to decide which specific file to use when there are
multiple files that could be used for a particular host. The highest
priority file is the one that is used.
Using this system, it is possible to have a file that contains all the
Packages from the original installation, centos-4-x86_64.xml in this case,
and then create a new file that contains updates that are made available
afterwards, centos-4-x86_64-updates.xml and centos-4-noarch-updates.xml
in this case. The priority of the update PackageLists just needs to be
higher so that they will be selected instead of the original installation
Packages.
The backup.example.com.xml contains a packalist for a specific host which
is qualified by the Client tag. Its Packages have a higher priority
than the update Packages. This is because this particular host requires
special Packages that are older than the ones available in the updates.
.. code-block:: xml
...
Simplifying Multi-Architecture Environments with :ref:`Altsrc `
=================================================================================================
Frequently multi-architecture environments (typically x86_64) will run
into problems needing to specify different architectures on different
groups for clients. For example, desktop machines may install 32-bit
compatibility packages in addition to 64-bit ones, while servers
may install only 64-bit packages. Specifying this in the Pkgmgr was
onerous, because different package targets (64bit, 32+64, etc) needed
to be specified on a package by group basis. Two features have been
implemented that should ease this situation considerably.
* The :ref:`Altsrc ` feature adds the ability to add a "bind as" directive
to entries. For example, the following entry, in a bundle:
.. code-block:: xml
would bind as if it were named bar, while the entry would still appear named "foo" in the client configuration specification.
* Pkgmgr now builds virtual package targets for any package with Instance
client elements. This means that if a client attempts to bind:
.. code-block:: xml
It will only include the instances listed in the package.
By using these features together, a bundle can include:
.. code-block:: xml
This in conjunction with a Pkgmgr entry that looks like:
.. code-block:: xml
Will result in a bound entry that looks like:
.. code-block:: xml
Altogether, this should move policy decisions about package architectures
to bundles/base.
Client Driver (Plugins) Specific Attributes
===========================================
Not all the attributes that are available in Pkgmgr are honoured by all
the client drivers. The following client drivers (plugins) have driver
specific attributes:
* :ref:`RPMng `