postgresql: ident authentication failed on fedora

Question

I know this question has been asked several times before, but all answers I could find tell you to add a line like the following to the pg_hba.conf file:

host all all 127.0.0.1/32 md5

So my pg_hba.conf file now looks like this:

# TYPE  DATABASE        USER            ADDRESS                 METHOD                                                                                                                                             

# "local" is for Unix domain socket connections only                                                                                                                                                               
local   all             all                                     peer
# IPv4 local connections:                                                                                                                                                                                          
host    all             all             127.0.0.1/32            ident
# IPv6 local connections:                                                                                                                                                                                          
host    all             all             ::1/128                 ident
# Allow replication connections from localhost, by a user with the                                                                                                                                                 
# replication privilege.                                                                                                                                                                                           
#local   replication     postgres                                peer                                                                                                                                              
#host    replication     postgres        127.0.0.1/32            ident                                                                                                                                             
#host    replication     postgres        ::1/128                 ident                                                                                                                                             

# I've added the following lines:
host    all             all              127.0.0.1/32           trust
host    all             all              ::1/128                trust
host    all             all              127.0.0.1/32           md5
host    all             all              ::1/128                md5
host    all             all              192.168.0.0/24         md5

I have set up several postgresql servers in the past on ubuntu and never had a problem. However, on fedora, I still get the following error message:

FATAL: Ident authentication failed for user "postgres"

The server is running on Fedora 27 Workstation and the postgresql version is 9.6.8-1.fc27.

Answer 1

You have two authentication rules for localhost in your pg_hba.conf, namely ..

host all  all  127.0.0.1/32  ident

and

host all  all  127.0.0.1/32  trust

I believe the system is trying to validate the two authentication options, making the trust option being overwritten by ident. Since you're most likely trying to use trust to authenticate from localhost (based on your file), just comment/delete the following line:

host all  all  127.0.0.1/32  ident

And afterwards either restart your database or reload the conf file using the following query:

SELECT pg_reload_conf();