Locating the PostgreSQL configuration file
Sometimes you get to manage a PostgreSQL instance on an unknown system, and this means you don’t know how to locate the PostgreSQL configuration file.An example could be when you are running PostgreSQL on a Docker container:
root@ff20ff72ee64:/# ps -auxwww
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
postgres 1 0.0 0.8 288596 18076 ? Ss 16:05 0:00 postgres
postgres 22 0.0 0.1 288732 3860 ? Ss 16:05 0:00 postgres: checkpointer
postgres 23 0.0 0.1 288596 3096 ? Ss 16:05 0:00 postgres: background writer
postgres 24 0.0 0.3 288596 6260 ? Ss 16:05 0:00 postgres: walwriter
postgres 25 0.0 0.1 289024 3068 ? Ss 16:05 0:00 postgres: autovacuum launcher
postgres 26 0.0 0.1 143856 2264 ? Ss 16:05 0:00 postgres: stats collector
postgres 27 0.0 0.1 288884 2564 ? Ss 16:05 0:00 postgres: logical replication launcher
root 70 0.0 0.1 19856 2236 pts/0 Ss 16:12 0:00 /bin/bash
Assuming you have the credentials of a PostgreSQL super user, you can ask PostgreSQL itself:
root@ff20ff72ee64:/# psql -U postgres -c 'SHOW config_file'
config_file
------------------------------------------
/var/lib/postgresql/data/postgresql.conf
(1 row)
You should have the administrator user credentials, since you have been assigned to manage this PostgreSQL instance!Of course, you can have your credentials stored into the
.pgpass file, as usual.
You can also save some extra “attaching” operations by macking
docker do all the stuff for you:
$ docker exec -it db psql -U ckan -c 'SHOW config_file'
config_file
------------------------------------------
/var/lib/postgresql/data/postgresql.conf
(1 row)
There are other methods, of course, including a search with
find(1) or locate.