Re: On login trigger: take three

út 22. 12. 2020 v 12:42 odesílatel Konstantin Knizhnik <
k(dot)knizhnik(at)postgrespro(dot)ru> napsal:

>
>
> On 22.12.2020 12:25, Pavel Stehule wrote:
>
>
> regress tests fails
>
> sysviews ... FAILED 112 ms
> test event_trigger ... FAILED (test process exited with
> exit code 2) 447 ms
> test fast_default ... FAILED 392 ms
> test stats ... FAILED 626 ms
> ============== shutting down postmaster ==============
>
>
> Sorry, fixed.
>

no problem

I had to fix doc

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 6ff783273f..7aded1848f 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1008,7 +1008,7 @@ include_dir 'conf.d'
trigger when a client connects. This parameter is switched on by
default.
Errors in trigger code can prevent user to login to the system.
I this case disabling this parameter in connection string can
solve the problem:
- <literal>psql "dbname=postgres options='-c
enable_client_connection_trigger=false'".
+ <literal>psql "dbname=postgres options='-c
enable_client_connection_trigger=false'"</literal>.
</para>
</listitem>
</varlistentry>

I am thinking again about enable_client_connection_trigger, and although it
can look useless (because error is ignored for superuser), it can be useful
for some debugging and administration purposes. Probably we don't want to
start the client_connection trigger from backup tools, maybe from some
monitoring tools. Maybe the possibility to set this GUC can be dedicated to
some special role (like pg_signal_backend).

+ <varlistentry id="guc-enable-client-connection-trigger"
xreflabel="enable_client_connection_trigger">
+ <term><varname>enable_client_connection_trigger</varname>
(<type>boolean</type>)
+ <indexterm>
+ <primary><varname>enable_client_connection_trigger</varname>
configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Enables firing the <literal>client_connection</literal>
+ trigger when a client connects. This parameter is switched on by
default.
+ Errors in trigger code can prevent user to login to the system.
+ I this case disabling this parameter in connection string can
solve the problem:
+ <literal>psql "dbname=postgres options='-c
enable_client_connection_trigger=false'"</literal>.
+ </para>
+ </listitem>
+ </varlistentry>

There should be note, so only superuser can change this value

There is should be tab-complete support

diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 3a43c09bf6..08f00d8fc4 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2970,7 +2970,8 @@ psql_completion(const char *text, int start, int end)
COMPLETE_WITH("ON");
/* Complete CREATE EVENT TRIGGER <name> ON with event_type */
else if (Matches("CREATE", "EVENT", "TRIGGER", MatchAny, "ON"))
- COMPLETE_WITH("ddl_command_start", "ddl_command_end", "sql_drop");
+ COMPLETE_WITH("ddl_command_start", "ddl_command_end",
+ "client_connection", "sql_drop");

/*
* Complete CREATE EVENT TRIGGER <name> ON <event_type>. EXECUTE
FUNCTION

Regards

Pavel

>
> --
>
> Konstantin Knizhnik
> Postgres Professional: http://www.postgrespro.com
> The Russian Postgres Company
>
>