hostlist is a small script that keeps a text list of hosts with tags and allows you to search that list. The purpose of this script is to facilitate other scripts. For example, if you have a script that needs the hostnames of only production weblogic servers, you would query hostlist first and then loop through the output.

All FQDNs are entered into the configuration file. This file is in YAML format and uses brace expansion very similar to how BASH does brace expansion. A list of values would be comma separated (eg: proxy{1,2} expands to proxy1, proxy2). A range is represented with two periods (eg: proxy{1..3} expands to proxy1, proxy2, proxy3).

The default location for the configuration file is /etc/hostlist.yaml

'extpxy00{1..4}.example.com':
  tags: [ 'prd', 'pxy', 'extpxy']
'extpxy00{1,2}.pre.example.com':
  tags: [ 'pre', 'pxy', 'extpxy']
'intpxy00{1,2}.example.com':
  tags: [ 'prd', 'pxy', 'intpxy']

You can list hosts by running hostlist with a list of tags you want to filter with. You can use any number of tags separated by a space. Using the above sample configuration, running "hostlist prd extpxy" would yield:

extpxy001.example.com
extpxy002.example.com
extpxy003.example.com
extpxy004.example.com

If you want to see a list of all the tags in the cached database, you can run "hostlist show". This list is not sorted in any way.