Rudder

Hmmmm...

The problem is, there is no standard installation path, only possible candidates on each type of OSes, that may or may not match the currently used one (eg. if the user uses home made packages storing things in /var/lib/my-postgres-9/ so it does not conflict with system packages).

For me, the problem is not that we do not cover every possible case, it is more that we do not give the possibility to do something else (we assume defaults but do not give easily the option to the user to do something else.)

For the ACL configuration, we could try to configure automatically, and just skip and output a helpful message explaining how to do it manually if we can't.

For the postgresql service name, it is an entirely other problem, as there is also no easy way to guess the name used. We can only try to detect it, that's what I did on the Rudder 3.1 init script (get all service candidates matching "postgresql", and use the last one, like "postgresql91")

We introduced correct detection of pg_hba file in #7395 (for rpm only, as debian defaults seem sane enough), and we detect corectly the postgres service name as of #6546

I tried to use Postgresql 11 with Rudder 5.0.9
At install I got the following error

  Installation : 1398866025:rudder-reports-5.0.9.release-1.EL.7.noarch                                                                                                                    12/36 
Unit postgresql.service could not be found.
INFO: Initializing PostgreSQL ...The service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use systemctl.
 Done
Failed to start postgresql.service: Unit not found.
psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
Postgresql failed to start! Halting
warning: %post(rudder-reports-1398866025:5.0.9.release-1.EL.7.noarch) scriptlet failed, exit status 1
Non-fatal POSTIN scriptlet failure in rpm package 1398866025:rudder-reports-5.0.9.release-1.EL.7.noarch
  Mise à jour  : openldap-2.4.44-21.el7_6.x86_64                                                                                                                                          13/36 
  Installation : openldap-clients-2.4.44-21.el7_6.x86_64                                                                                                                                  14/36 
  Installation : perl-Digest-1.17-245.el7.noarch                                                                                                                                          15/36 

indeed, service name is postgresql-11, which isn't find by

systemctl list-unit-files --type service | awk -F'.' '{print $1}' | grep -E "^postgresql[0-9]*$" 

then the following command fails

service ${POSTGRESQL_SERVICE_NAME} initdb
The service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use systemctl.

when using package from distrib¶

doc https://www.postgresql.org/download/linux/redhat/ says that
RHEL 5,6 should do

   service postgresql initdb
   chkconfig postgresql on

rhel7 should do

  postgresql-setup initdb
  systemctl enable postgresql.service
  systemctl start postgresql.service

when using package downloaded from postgresql repo¶

same as when using from distro, except we need full path from postgresql-setup

/usr/pgsql-9.6/bin/postgresql96-setup initdb
systemctl enable postgresql-9.6
systemctl start postgresql-9.6

/usr/pgsql-10/bin/postgresql-10-setup initdb
systemctl enable postgresql-10
systemctl start postgresql-10

/usr/pgsql-11/bin/postgresql-11-setup initdb
systemctl enable postgresql-11
systemctl start postgresql-11

Note the extra *-* for 10 and after