NAME

       Rex::CMDB - Function to access the CMDB (configuration management database)

DESCRIPTION

       This module exports a function to access a CMDB via a common interface.

SYNOPSIS

        use Rex::CMDB;

        set cmdb => {
            type => 'YAML',
            path => [
                'cmdb/{hostname}.yml',
                'cmdb/default.yml',
            ],
            merge_behavior => 'LEFT_PRECEDENT',
        };

        task "prepare", "server1", sub {
          my $virtual_host = cmdb("vhost");
          my %all_information = cmdb;
        };

EXPORTED FUNCTIONS

   set cmdb
       CMDB is enabled by default, with Rex::CMDB::YAML as default provider.

       The path option specifies an ordered list of places to look for CMDB information. The path
       specification supports any Rex::Hardware variable as macros, when enclosed within curly
       braces. Macros are dynamically expanded during runtime. The default path settings is:

        [qw(
            cmdb/{operatingsystem}/{hostname}.yml
            cmdb/{operatingsystem}/default.yml
            cmdb/{environment}/{hostname}.yml
            cmdb/{environment}/default.yml
            cmdb/{hostname}.yml
            cmdb/default.yml
        )]

       Please note that the default environment is, well, "default".

       You can define additional CMDB paths via the `-O` command line option by using a
       semicolon-separated list of `cmdb_path=path` key-value pairs:

        rex -O 'cmdb_path=cmdb/{domain}.yml;cmdb_path=cmdb/{domain}/{hostname}.yml;' taskname

       Those additional paths will be prepended to the current list of CMDB paths (so the last
       one specified will get on top, and thus checked first).

       The CMDB module looks up the specified files in order and then returns the requested data.
       If multiple files specify the same data for a given case, then the first instance of the
       data will be returned by default.

       Rex uses Hash::Merge internally to merge the data found on different levels of the CMDB
       hierarchy. Any merge strategy supported by that module can be specified to override the
       default one. For example one of the built-in strategies:

        merge_behavior => 'LEFT_PRECEDENT'

       Or even custom ones:

        merge_behavior => {
            SCALAR => { ... },
            ARRAY  => { ... },
            HASH   => { ... },
        }

       For full list of options, please see the documentation of Hash::Merge.

   cmdb([$item, $server])
       Function to query a CMDB. If this function is called without $item it should return a hash
       containing all the information for the requested server. If $item is given it should
       return only the value for $item.

        task "prepare", "server1", sub {
          my $virtual_host = cmdb("vhost");
          my %all_information = cmdb;
        };