Re: On login trigger: take three

út 22. 12. 2020 v 12:42 odesílatel Konstantin Knizhnik <k.knizhnik@postgrespro.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

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