CLI: conf get|set postgresql

[jesperpedersen]

conf set postgresql <server> <key> <value> [reload]
conf get postgresql <server> <key>

In order to set a PostgreSQL (postgresql.conf) GUC. User must have access to 'postgres'

[fluca1978]

Uhm, I don't understand the use case for this. Since we can already get the primary information out of pgagraol, why pass a configuration parameter to PostgreSQL directly?
Besides, I woul see a cli lile : primary conf get|set <key> <value> <immediate_reload>.

[jesperpedersen]

I meant <server> instead of primary, but I like the get part too

[fluca1978]

I meant <server> instead of primary, but I like the get part too

But again, is this a dedicated and pgagroal-implemented way to send a message to a server to change a GUC?
What is the advantaged instead of psql -h pgagroal-host -c 'SET foo = true;' postgres?

[jesperpedersen]

@fluca1978 Precisely, it is a unified interface across the projects to read/write GUC directly from a server without using psql

[fluca1978]

@fluca1978 Precisely, it is a unified interface across the projects to read/write GUC directly from a server without using psql

Are we going to implement as fixed queries, like SELECT setting FROM pg_settings WHERE name = $1;? Because, according to me, the difficult part is setting a parameter (is this possible in the message protocol?) because we don't know the context (that's lead to UPDATE pg_settings ...).

[jesperpedersen]

How the ALTER SYSTEM SET command is run is part of the issue to figure out. get should be straight forward

[fluca1978]

I am still thinking about the command line of this feature, and I'm not convinced.
Why not introducing a flag, like:

pgagroal-cli conf get --server primary max_connections

Clearly, the --server flag points to a section in pgagroal.conf, hence the default value will be --server pgagroal.
Drawback: this can confuse users when asking for a pgagroal setting related to a server, e.g.,:

pgagroal-cli --server primary conf get port

against something like:

pgagroal-cli conf get primary.port

[jesperpedersen]

Yeah, we could use --server or --postgresql for this. In the full response we could highlight it is coming from PostgreSQL and not pgagroal