The problem
The CKAN installation documentation shows you how to list the installed PostgreSQL databases.
The command looks like this:
sudo -u postgres psql -l
When I try that in my shell, I get an error:
$ sudo -u postgres psql -l
sudo: psql: command not found
The workaround
Daniel2d2art on the CentOS forum worked around the problem by fully qualifying the path to psql.
My psql lives in the directory /usr/pgsql-9.2/bin
, so my workaround now looks like this:
sudo -u postgres /usr/pgsql-9.2/bin/psql -l
When I try that in my shell, it works:
$ sudo -u postgres /usr/pgsql-9.2/bin/psql -l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
--------------+----------+----------+-------------+-------------+-----------------------
postgis_test | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
(4 rows)
How do I fix it properly?
I shouldn't have to fully qualify the path, right?
The postgres user already has psql in its path:
$ sudo -u postgres echo $PATH
/usr/pgsql-9.2/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin
How do I fix this properly?
Best Answer
Why sudo ignores your path
sudo doesn't use your user's path or the postgres user's path. sudo has its own path, defined by the the
secure_path
variable in the file/etc/sudoers
.The output of
echo $PATH
is misleading in this case. To see the path that sudo really uses, useprintenv PATH
instead. In my case, the output looked like this:The output doesn't contain
/usr/pgsql-9.2/bin
, where psql lives, so it's not in sudo's path either.To fix the problem you can add where psql lives to the
secure_path
variable.How to tell sudo where psql lives
Use
sudo visudo
to open/etc/sudoers
in vi.The file should contain a line like this:
This line sets the path for sudo. The part after the equals sign is the same as the output of the previous
printenv PATH
example.Replace it with something like this:
The replacement appends
/usr/pgsql-9.2/bin
to the path list. The path list separator is a colon (:
).Save and close the file.
To check that it worked, try the
printenv PATH
command again:Looks good!
Now try the
psql -l
command:It works!
Thanks to Drew Khoury who pointed me to a solution for a similar problem on Super User.