ERROR: DATA_SERVER_HOST environment variable is not set, cannot continue

[benajamin]

Describe the problem:
I installed, started Pixelator, then started pyStxm. A window poped up with the following:

An unhandled exception occurred. Please report the problem
using the error reporting dialog or via email to <russ.berg@lightsource.ca>.
A log has been written to "".

Error information:
--------------------------------------------------------------------------------
2025-10-30, 18:41:05
--------------------------------------------------------------------------------
<class 'Exception'>: 
ERROR: DATA_SERVER_HOST environment variable is not set, cannot continue
--------------------------------------------------------------------------------
  File "/home/watts/dev/Pixelator/pyStxm/pyStxm/./cls/applications/pyStxm/runPyStxm.py", line 244, in <module>
    go()
  File "/home/watts/dev/Pixelator/pyStxm/pyStxm/./cls/applications/pyStxm/runPyStxm.py", line 219, in go
    from cls.applications.pyStxm.stxmMain import pySTXMWindow
  File "/home/watts/dev/Pixelator/pyStxm/pyStxm/cls/applications/pyStxm/../../../cls/applications/pyStxm/stxmMain.py", line 24, in <module>
    from cls.applications.pyStxm.main_obj_init import MAIN_OBJ
  File "/home/watts/dev/Pixelator/pyStxm/pyStxm/cls/applications/pyStxm/../../../cls/applications/pyStxm/main_obj_init.py", line 63, in <module>
    MAIN_OBJ = main_object_base(beamline_desc, endstation_name, beamline_cfg_dct=bl_config_dct, main_cfg=appConfig)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/watts/dev/Pixelator/pyStxm/pyStxm/cls/applications/pyStxm/../../../cls/appWidgets/main_object.py", line 143, in __init__
    raise Exception("ERROR: DATA_SERVER_HOST environment variable is not set, cannot continue")
0.0.1

The console had the following output:

(pyStxm) watts@Flask:~/dev/Pixelator/pyStxm/pyStxm$ ./runpyStxm.sh 
/home/watts/dev/Pixelator/pyStxm/miniforge3/envs/pyStxm/lib/python3.11/site-packages/epics/ca.py:28: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
  from pkg_resources import resource_filename
Successfully wrote to /home/watts/dev/Pixelator/pyStxm/pyStxm/cls/applications/pyStxm/../../../bcm/backend.py
Screen: HDMI-A-1
Final destination screen size: 3440 x 1440
get_style: Using stylesheets in dark_linux_hires_disp
Loading beam line configuration from [amb_bl10ID1]

[RussBerg]

I need to take a look again at merging an environment variable but for now set DATA_SERVER_HOST to the IP addr of the machine that Pixelator is being run from

[benajamin]

I added export DATA_SERVER_HOST="127.0.0.1" to runpyStxm.py and now I don't get the error popup, but it seems to get stuck on a non-existent NX_server.

(pyStxm) watts@Flask:~/dev/Pixelator/pyStxm/pyStxm$ ./runpyStxm.sh 
/home/watts/dev/Pixelator/pyStxm/miniforge3/envs/pyStxm/lib/python3.11/site-packages/epics/ca.py:28: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
  from pkg_resources import resource_filename
Successfully wrote to /home/watts/dev/Pixelator/pyStxm/pyStxm/cls/applications/pyStxm/../../../bcm/backend.py
Screen: HDMI-A-1
Final destination screen size: 3440 x 1440
get_style: Using stylesheets in dark_linux_hires_disp
Loading beam line configuration from [amb_bl10ID1]
Connecting to data server at tcp://127.0.0.1:56566
Checking if process [nx_server] is running on host [IPADDRHERE] port [5555]
        ERROR: Send operation timed out.
        ERROR: Check host [IPADDRHERE] port [5555] and make sure that mongodb is running

To be clear, I have "NoHardware" PixelatorController running on the same machine with ports:

   "publisherPort" : "56561",
   "requestPort" : "56562",

[RussBerg]

As I think you discovered the name of the beamline configuration needed to be set in app.ini as it was still set to an EPICS beamline config here at the CLS.

Don't put the env var in runpyStxm.py, these environment variables are intended to be set in reqd_env_vars.sh which will be sourced when you start pyStxm with the start script runpyStxm.sh

[benajamin]

I moved the env var as requested and set the bl_config to sls_x07da_polLux, and now pyStxm starts as expected.

I also had to set the dataPublisherPort to 56563 in the Pixelator settings.