If libpq has been compiled with LDAP support (option --with-ldap for configure) it is possible to retrieve connection options like host or dbname via LDAP from a central server. The advantage is that if the connection parameters for a database change, the connection information doesn't have to be updated on all client machines.
LDAP connection parameter lookup uses the connection service file pg_service.conf (see Section 29.14). A line in a pg_service.conf stanza that starts with ldap:// will be recognized as an LDAP URL and an LDAP query will be performed. The result must be a list of keyword = value pairs which will be used to set connection options. The URL must conform to RFC 1959 and be of the form
where hostname defaults to localhost and port defaults to 389.
Processing of pg_service.conf is terminated after a successful LDAP lookup, but is continued if the LDAP server cannot be contacted. This is to provide a fallback with further LDAP URL lines that point to different LDAP servers, classical keyword = value pairs, or default connection options. If you would rather get an error message in this case, add a syntactically incorrect line after the LDAP URL.
A sample LDAP entry that has been created with the LDIF file
version:1 dn:cn=mydatabase,dc=mycompany,dc=com changetype:add objectclass:top objectclass:groupOfUniqueNames cn:mydatabase uniqueMember:host=dbserver.mycompany.com uniqueMember:port=5439 uniqueMember:dbname=mydb uniqueMember:user=mydb_user uniqueMember:sslmode=require
might be queried with the following LDAP URL: