<!-- Kamailio Project uses GitHub Issues only for bugs in the code or feature requests. Please use this template only for bug reports.

If you have questions about using Kamailio or related to its configuration file, ask on sr-users mailing list:

* https://lists.kamailio.org/mailman3/postorius/lists/sr-users.lists.kamailio....

If you have questions about developing extensions to Kamailio or its existing C code, ask on sr-dev mailing list:

* https://lists.kamailio.org/mailman3/postorius/lists/sr-dev.lists.kamailio.or...

Please try to fill this template as much as possible for any issue. It helps the developers to troubleshoot the issue.

Note that an issue report may be closed automatically after about 2 months if there is no interest from developers or community users on pursuing it, being considered expired. In such case, it can be reopened by writing a comment that includes the token `/notexpired`. About two weeks before considered expired, the issue is marked with the label `stale`, trying to notify the submitter and everyone else that might be interested in it. To remove the label `stale`, write a comment that includes the token `/notstale`. Also, any comment postpone the `expire` timeline, being considered that there is interest in pursuing the issue.

If there is no content to be filled in a section, the entire section can be removed.

You can delete the comments from the template sections when filling.

You can delete next line and everything above before submitting (it is a comment). -->

### Description

<!-- Explain what you did, what you expected to happen, and what actually happened. -->

### Troubleshooting

#### Reproduction

<!-- If the issue can be reproduced, describe how it can be done. -->

#### Debugging Data

<!-- If you got a core dump, use gdb to extract troubleshooting data - full backtrace, local variables and the list of the code at the issue location.

gdb /path/to/kamailio /path/to/corefile bt full info locals list

If you are familiar with gdb, feel free to attach more of what you consider to be relevant. -->

``` I want to read params from environment, so define #!defenv MYSQL_IP #!trydef DBURL "mysql://kamailio:kamailio@MYSQL_IP/kamailio"

but It can't read this ”MYSQL_IP“。

root@d2e1fcc3f89e:/# env |grep MYSQL* MYSQL_URL=172.16.4.111 MYSQL_IP=172.16.4.111

```

#### Log Messages

<!-- Check the syslog file and if there are relevant log messages printed by Kamailio, add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). --> ``` 0(34) ERROR: db_mysql [km_my_con.c:166]: db_mysql_new_connection(): driver error: Unknown server host 'MYSQL_IP' (-2) 0(34) ERROR: <core> [db.c:324]: db_do_init2(): could not add connection to the pool 0(34) ERROR: dispatcher [dispatch.c:955]: ds_connect_db(): cannot initialize db connection 0(34) ERROR: dispatcher [dispatch.c:989]: ds_init_db(): unable to connect to the database 0(34) ERROR: dispatcher [dispatcher.c:439]: mod_init(): could not initiate a connect to the database 0(34) ERROR: <core> [core/sr_module.c:1030]: init_mod(): Error while initializing module dispatcher (/usr/lib/x86_64-linux-gnu/kamailio/modules/dispatcher.so)

```

#### SIP Traffic

<!-- If the issue is exposed by processing specific SIP messages, grab them with ngrep or save in a pcap file, then add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). -->

``` (paste your sip traffic here) ```

### Possible Solutions

<!-- If you found a solution or workaround for the issue, describe it. Ideally, provide a pull request with a fix. -->

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` version: kamailio 5.7.4 (x86_64/linux) flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, MEM_JOIN_FREE, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLOCKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled with gcc 12.2.0

```

* **Operating System**:

<!-- Details about the operating system, the type: Linux (e.g.,: Debian 8.4, Ubuntu 16.04, CentOS 7.1, ...), MacOS, xBSD, Solaris, ...; Kernel details (output of `lsb_release -a` and `uname -a`) -->

``` cat /proc/version Linux version 3.10.0-1160.105.1.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC) ) #1 SMP Thu Dec 7 15:39:45 UTC 2023

```