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Segmentation fault when running in Docker container #1019
Description
I'm trying to run a Python script in a Docker container talking with db2, but I just get a segmentation fault. We can run the Python-script locally, but when I try it from a container it fails, and using db2cli to debug doesn't help.
- Operating System Name: Dockerfile
FROM python:3.12 - db2level output from clidriver if in use:
$ ./db2level
DB21085I This instance or install (instance name, where applicable: "*") uses
"64" bits and DB2 code release "SQL11059" with level identifier "060A010F".
Informational tokens are "DB2 v11.5.9.0", "special_50315",
"DYN2410311831AMD64_50315", and Fix Pack "0".
Product is installed at "..".
- Target Db2 Server Version: ??
- Python Version: 3.12.11
- ibm_db version: 3.2.6
- For non-Windows, output of below commands:
uname = Linux
uname -m = x86_64 - Value of below environment variables if set:
IBM_DB_HOME:
PATH:
LIB/LD_LIBRARY_PATH/DYLD_LIBRARY_PATH:
Dockerfile:
FROM python:3.12
RUN pip install ibm_db --no-binary :all: --no-cache-dir
RUN ln -s /var/run/secrets/db2-license/db2consv_zs.lic /usr/local/lib/python3.12/site-packages/clidriver/license/db2consv_zs.lic
db2cli validate:
$ ./db2cli validate -connstring "UID=xxx;PWD=xxx;HOSTNAME=xxx;PORT=5025;DATABASE=xxx" -displaylic
===============================================================================
Client information for the current copy:
===============================================================================
Client Package Type : IBM Data Server Driver For ODBC and CLI
Client Version (level/bit): DB2 v11.5.9.0 (special_50315/64-bit)
Client Platform : Linux/X8664
Install/Instance Path : ..
DB2DSDRIVER_CFG_PATH value: <not-set>
db2dsdriver.cfg Path : ../cfg/db2dsdriver.cfg
DB2CLIINIPATH value : <not-set>
db2cli.ini Path : ../cfg/db2cli.ini
db2diag.log Path : db2diag.log
===============================================================================
db2dsdriver.cfg schema validation for the entire file:
===============================================================================
Note: The validation utility could not find the configuration file
db2dsdriver.cfg. The file is searched at "../cfg/db2dsdriver.cfg".
Segmentation fault (core dumped)
Activity
Earammak commentedon Jun 26, 2025
@Kyrremann , Can you please share from which path you are running. Can you please share the sample python script. Looks like you are facing issue in running db2 command only from docker.
bchoudhary6415 commentedon Jun 26, 2025
@Kyrremann Please delete or edit your above comment,
Your userID and password are visible here.
Thank you
Kyrremann commentedon Jun 26, 2025
Thanks for letting me know, I was so sure I had triple checked for that kind of blunder! Luckily it's an internal database, but still need to make a new password.
The path is
/usr/local/lib/python3.12/site-packages/clidriver/bin. In this issue I've just showed the problems using the db2-tools, as I though it would be simpler to reproduce.The Python script:
The output from running the script in our environment is:
As you can see, everything looks okay when running the Python-script, but it stops at the last line and exit. Since we are running in Kubernetes we get the exit code
139which meansSIGSEGV.bchoudhary6415 commentedon Jun 26, 2025
@Kyrremann , Please try to edit the logs and than paste.
Thank you
Earammak commentedon Jun 26, 2025
@Kyrremann I would request you to share the trace for python script.
To collect the traces use below commands:
db2trc on -f 1.trc
python test.py
db2trc off
db2trc flw 1.trc 1.flw
db2trc fmt 1.trc 1.fmt
db2trc fmt -cli 1.trc 1.cli
Share these 1.flw, 1.fmt and 1.cli files here. We will look into trace files.
x10an14-nav commentedon Jun 27, 2025
Thanks for helping us out @Earammak! Here are the files as requested:
https://gist.github.com/x10an14-nav/a445d06e90b6177aaf569f62438e49c4
bimalkjha commentedon Jul 11, 2025
@Kyrremann You have not provided info about
Target Db2 Server Version: ??while opening the issue. Are you trying to connect to a z/OS server or iSeries server? Are you able to connect to the same server using same license file when you install ibm_db outside docker on Linux OS? Please clarify. Thanks.bimalkjha commentedon Jul 11, 2025
@x10an14-nav I checked the shared log files. Thanks for sharing it.
In 1.fmt file, we can see below logs:
1.flw:
By looking on traces, we can see that clidriver is trying to install client side db2connect license but during the installation, it crashes under
LicAddLicense()function. Your license file is for Db2 for z/OS server. If you are using this license to connect to iSeries server, then please use correct license.If you are trying to connect to z/OS server, please check file permission of db2consv_zs.lic file. If you have empty line at end of this file, please remove it. This license file is a text file, so make sure if you transferred it from an OS which do not match OS of docker, then file format might have changed or corrupted. Please provide more info to understand your issue. Thanks.
Kyrremann commentedon Jul 14, 2025
I'll find out about the zOS vs iSeries, and come back on that.Just got told that we are using zOS servers.
There was one new line at end of file (which is pretty normal/recommended on unix files), but I got the same error when I removed it. File permissions are set to read, but there is one thing I haven't tried yet. The way we side load the license is by using symbol links, maybe the client doesn't follow symbol links? I'll try without linking tomorrow.
Maybe it's a wrong licenseKyrremann commentedon Jul 15, 2025
I finally made it work! The problem was symlinks, the client doesn't follow symlinks. So when I switched to a writable filesystem and copied the license instead of using symlink the
validatecommand successfully completed. Another thing is that I needed the new line at the end of the file too.