It's useful to have a confirmation of which database repmgr is trying
to connect to when the -S/--superuser connection is provided.
It will always be the database defined in the repmgr.conf "conninfo"
parameter, but having the name available is useful when e.g.
troubleshooting issues with .pgpass configuration.
The removal of some extensions functions means it's not possible to
follow the conventional incremental upgrade path; instead we'll
create a script for direct upgrades to 5.1.
Commit 0574279 set the file permissions to 0600 rather than the user's
umask, but if initdb was executed with -g/--allow-group-access, the
file is maintained with 0640, so we'll just maintain the existing
permssions.
It's possible a repmgrd instance might still be in the primary check
phase while a primary has already been promoted. Therefore it's
necessary to check for new primary notifications here, so we can
follow a new primary as quickly as possible.
We have a --downstream option to check for attached nodes, but it
would be useful to have a corresponding --upstream option too.
A following patch will adapt the behaviour of this option when executed
on the primary node.
This is mainly useful for the --data-directory-config option, which
requires permission to read pg_settings to verify that the data
directory configured in "repmgr.conf" matches the data directory
actually in use.
If pg_settings read permission is not available, repmgr will fall
back to a simple check that the data directory configured in
"repmgr.conf" is a valid PostgreSQL directory. This is not entirely
foolproof, as it's possible PostgreSQL could be using a different
data directory.
No need to check for empty parameters; this is something left over
from the original configuration file parsing. Since converting
to use the PostgreSQL-based configuration file parsing, it is
redundant.
From PostgreSQL 12, the SQL-level function "pg_promote()" can be used
to promote a PostgreSQL instance, however usage is restricted to
superusers and users to whom explicit execution permission for this
function has been granted.
Therefore, if execution permission is not available, fall back to
"pg_ctl promote".
