如何从Ansible中的组中获取包含特定字符串的主机名

Question

I'm using Ansible and need to lookup my database server to use in a config file.

I have a group of all database servers: groups.rds and I know that the server I'm looking for contains a certain string, eg. "development".

What is the cleanest way to find that hostname?

I'm looking for something like this: groups.rds.contains("development").first()

Answer 1

You can do this with the select filter , combined with the match filter .

groups.rds | select("match", ".*production.*") | first

But you're asking for the cleanest solution. From here it looks like you're trying to identify an environment (development) based on a host name. If that's the case, wouldn't it make sense to have another group for this?

If you'd had something like this:

[non_rds]
some.unrelated.development.host

[rds]
some.production.host
some.staging.host
some.development.host

[production]
some.production.host

[staging]
some.staging.host

[development]
some.development.host
some.unrelated.development.host

Then it would be very easy to get the intersection of these groups:

groups.rds | intersect(groups.development) | first

This would give you only the hosts which are in both groups rds and development , which is some.development.host .