How to set value of ipa_hostname directive in sssd.conf using Augeas
Took a couple days but I finally figured this out. I added some extra code to show how to address another section in the same file. Hope this helps.
$domain = abc.net
augeas { "sssd.conf ipa_hostname":
lens => 'sssd.lns',
incl => '/etc/sssd/sssd.conf',
changes => [
"set target[ . = 'sssd']/services 'nss, sudo, pam, ssh'",
"set target[ . = 'sssd']/config_file_version 2",
"set target[ . = 'sssd']/domains ${domain}",
"set target[ . = 'domain/${domain}']/ipa_hostname ${hostname}.${domain}",
],
notify => Service["sssd"]
}