[Date Prev][Date Next]
Re: ITS#3781 back-config doesn't work with xxx
>>> Is there a description somewhere of what it means to support
>>> back-config? For example, how would back-perl do it? The admin can
>>> write a Perl config() function which defines new slapd.conf directives;
>>> only a few directives are hardcoded.
>> I suggest that backends like back-perl just define a "perl-" directive
>> that allows arbitrary length and args which are passed to the
>> user-provided config routine. I see it a bit harder to implement "emit"
>> in a consistent way, though.
> That implies that you'll only have a single attributeType for back-perl
> config directives. I guess it would work, but it pretty much means
> implementing a table-driven config engine in perl, to manage things from
> there (assuming you want to support LDAP_MOD_DELETE and have full
> runtime reconfigurability).
Well, assume one doesn't want to support that for now then:-)
> Or maybe a set of perl hooks for constructing schema tables that can
> be passed to config_register_schema(), so that the perl module can
> properly define its config items. I think either way this is a fair
> chunk of perl XS code.
Seems a pity to put this in XS, other programmable backends could
have use for it.
Maybe I just don't know back-config well enough yet, but I don't
get the problem with the single directive approach. Keeping
general programmable backends in mind, I imagine something like -
* Make a general olcStatement attribute. OCTET STRING, X-ORDERED.
* Pass slapd.conf statements or olcStatement values to the current
bi->bi_db_config() as usual. If that succeeds from slapd.conf,
save the raw statement as a new olcStatement value.
* Do not accept run-time configuration operations by default,
since that might confuse existing Perl programs.
Here is where I imagine I may be departing from how back-config
thinks, but anyway -
If/when someone feels like implementing run-time configuration:
* Allow a new perl routine "dyn_config" which takes a modification
request to config parameters as an argument and returns success
To perform a config modification request, block future config
modifications, check that the change would be valid as far as
back-ldif is concerned (by simulating the change with the noop
control?), call dyn_config(), perform the back-ldif
modification, and cancel the blocking.
* Create a Perl routine "read_config" which the Perl program can
call, which returns the current config statements - or the
statements matching an optional parameter to read_config.
* There could be a "config-option" statement to describe config
options the database will accept. In that case, generate
database-specific - not backend-specific - config attributes,
with OIDs generated from the option name and some reserved
prefix. That would provide some syntax checking but otherwise
be treated just like olcStatement.
If a database has no config-option statements, or if there is
a 'config-option *' statement, fall back on olcStatement.