This happens because MariaDB ODBC distinguish between empty or null username or password, so if we send empty string values it tries to use local system user. ODBC stored values are tests:tests but instead query is done using zabbix as user

  5204:20190210:160003.410 In get_value() key:'db.odbc.select[myserver]'
  5204:20190210:160003.410 In get_value_db() key_orig:'db.odbc.select[myserver]' query:'select 1'
  5204:20190210:160003.410 In zbx_odbc_connect() dsn:'myserver' user:''
  5204:20190210:160003.411 zbx_odbc_diag(): [SQL_SUCCESS]
  5204:20190210:160003.411 zbx_odbc_diag(): [SQL_SUCCESS]
  5204:20190210:160003.411 zbx_odbc_diag(): [SQL_SUCCESS]
  5204:20190210:160003.415 zbx_odbc_diag(): [SQL_ERROR]:[28000][1045][[unixODBC][ma-3.0.8]Access denied for user 'zabbix'@'localhost' (using password: NO)]
  5204:20190210:160003.416 End of zbx_odbc_connect()
  5204:20190210:160003.416 End of get_value_db():NOTSUPPORTED

An isql session (odbc trace) using odbc.ini #isql myserver:

ODBC][6969][1549817891.100123][SQLConnect.c][3700]
        Entry:
            Connection = 0x19f9050
            Server Name = [myserver][length = 26 (SQL_NTS)]
            User Name = [NULL]
            Authentication = [NULL]
        UNICODE Using encoding ASCII 'ISO8859-1' and UNICODE 'UCS-2LE'

[ODBC][6969][1549817891.117190][SQLConnect.c][4273]
        Exit:[SQL_SUCCESS]

Being sent user & password as null values ODBC uses stored credentials at odbc.ini file and login is successful 

Patch proposed is very simple, if user or pass are empty send them to ODBC as null values. With this small patch it works as expected.

patched zabbix-server log:

  5624:20190210:160953.717 In zbx_odbc_connect() dsn:'myserver' user:''
  5624:20190210:160953.718 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.718 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.718 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.725 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.725 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.725 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.725 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.726 zbx_odbc_diag(): [SQL_SUCCESS]
  5624:20190210:160953.726 zbx_odbc_connect() connected to MariaDB(10.01.000038) using libmaodbc.so(03.00.0008)
  5624:20190210:160953.726 End of zbx_odbc_connect()
  5624:20190210:160953.726 In zbx_odbc_select() query:'select 1'
  5624:20190210:160953.726 zbx_odbc_diag(): [SQL_SUCCESS]

Hello Jose Deniz,

Thank you for registering this thread.

Is it correct that you are trying an option to not store any other database credentials inside Zabbix database? Instead, you want to store credentials on the filesystem only?

Hello aigars.kadikis,

Yes. Configured in that way. odbc.ini storing DSN, user, password, database and server. Nothing is stored at zabbix database but key and SQL query. I've been using this model widely on 3.0 LTS

Hi,

Thank you for reporting the issue.

I was able to replicate this behavior with MariaDB connector 3.1.0RC version. Not sure if this warrants a fix from the Zabbix side or some additional clarification in the documentation - I'll pass this on to the development team for them to discuss internally.

I've been using this model widely on 3.0 LTS

jadeniz, you mean the patch? I'm surprised to hear that 4.0 behaves any different to 3.0.

@cyclone This configuration worked in Zabbix 2.4 and 3.0. I found this problem upgrading 3.0 servers and none of them (2.4 or 3.0) were patched. Basically they stopped working after 4.0 upgrade.

(1) [D] Update ODBC description to mention what specifying username and password does.

User name Enter the database user name (optional if user is specified in odbc.ini)
Password Enter the database user password (optional if password is specified in odbc.ini)

To:

User name Enter the database user name (optional, if left blank then user specified in odbc.ini will be used)
Password Enter the database user password (optional, if left blank then password specified in odbc.ini will be used)

(2) [D] Upgrade notes

While MySQL and PostgreSQL drivers should work the same as before the upgrade, due to changes required for MariaDB driver to work correctly some unixODBC drivers might need reconfiguration in cases where empty username or password was configured in Database monitor item and it was not meant to work as mentioned below:
user name (optional, if left blank then user specified in odbc.ini will be used)
user password (optional, if left blank then password specified in odbc.ini will be used)

If empty password or user is required it needs to be specified in odbc.ini instead.

Successfully tested

Zabbix typically uses

if ('\0' == *some_string)

instead of

if ('\0' == some_string[0])

vso yes cyclone that is true and was noticed but forgotten to change, thanks a lot for reminding.

cyclone You are welcome!

Fixed in:

• pre-4.0.7rc1 r91887
• pre-4.2.1rc1 r91888
• pre-4.4.0alpha1 (trunk) r91889