Is there an option to save logs?
There is an option to use loggings inside as a write on the screen.
But when trying to save logs, it does not work, it does not create the logging file.
Hi @BugzTheBunny,
Thank you for sharing with the Streamlit community!
This post covers how to enable logging via the command line. You mentioned that you have already tried to save logs â can you provide a code snippet or screenshot of the commands youâve already tried?
Best,
Caroline
1 Like
Hi @Caroline !
The code is pretty simple:
import streamlit as st
import logging
logging.basicConfig(filename='example.log')
logging.debug('This message should go to the log file')
But for some reason the exmaple.log file is not being created, and u did run it now using
streamlit run app.py --logger.level=debug
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Hi @BugzTheBunny,
You will need to add a parameter to what youâre entering in the command line that will redirect stderr to a file. The syntax of this parameter should be â2>logfilename.txtâ
For example:
streamlit run streamlit_app.py --logger.level=debug 2>logs.txt
Best,
Caroline
2 Likes
Okay, thatâs great for a run command, is there an option to make it in a config file?
Thanks for the answer!!
2 Likes
Hey!
Thanks again, really helpful.
But I actually meant is there an option to use the â2> logs.logâ into the config?
If not thatâs also okay, Iâm using docker, so thatâs not really an issue, just wanted to know 
Hi @BugzTheBunny,
That piece is just redirecting stderr to a different file, so you would need to include it in the command unfortunately.
Best,
Caroline
1 Like
Hi again⊠this is not working when using docker 
I run the code, but while using docker for this, it does not work when using dockerâŠ
the output is still being seen in the console, rathar then being writtenin the fileâŠ
beyond that, the file itself is not being created.
DockerFile:
FROM python:3.8-slim-buster
COPY streamlit_src /app
COPY aoi_defects_clustering/src /app/src
COPY unit_level_analysis /app/unit_level_analysis
COPY machines.csv /app/machines.csv
WORKDIR /app
RUN python -m pip install --upgrade pip
RUN pip install -r requirements.txt
EXPOSE 8889
ENTRYPOINT ["streamlit","run","--server.port","8889","app.py","--logger.level=info","2>","streamlit_logs.log"]
Am I missing something?
1 Like
Found a solution!
FROM python:3.8-slim-buster
COPY streamlit_src /app
...
...
COPY run_app.sh /app/run_app.sh
RUN python -m pip install --upgrade pip
RUN pip install -r requirements.txt
RUN chmod +x /app/run_app.sh
WORKDIR /app
EXPOSE 8889
ENTRYPOINT ["/bin/bash"]
CMD ["./run_app.sh"]
run_app.sh:
streamlit run --server.port 8889 app.py --logger.level=info 2> streamlit_logs.log
2 Likes
Nonetheless, it would be a nice feature if we could also enable file logging in config.toml besides the log level 
1 Like
A small suggestion for improving your Dockerfile:
WORKDIR /app
COPY . .
and add a .dockerignore file to the repo so that only the wanted files get copied to the container image.
1 Like
Will COPY . . just copy all of the content? if so, thatâs not what i need unfortunately, there are a lot of items i need to ignore, si this is a shorter way.
Or im missing something?
Yes.
But you can use also inverted logic in the ignore files, for example
# Ignore everything
*
# But not these files...
!file1.py
!file2.py
1 Like
Great to know!
Im pretty new to docker, been using it for about a month only, and would not really call myself a poweruser of this.
Will use it in the future, but at this point the shorter way is just to copy these 4 files 
Thanks a lot tho!
As far as i know, the .dockerignore uses the same syntax/logic as the .gitignore files.
So you can use this knowledge in different cases.
1 Like
Will dig deeper then
(10 months later) 
I have a similar, but slightly different problem.
Running my app locally, I can download (from within the app) a log file containing all the log-messages.
However, when I run the hosted app, I see the logs only in the little âmanage appâ-shell.
The file that I download is always empty!
Any help would be appreciated.
Here are some screenshots and a link to the app:
Hosted
Local
app
I suspected that loggingâs config is not correct.
So, just for the sake of debugging things, I tried a new, easy to config library called lovely-logger.
Locally, everything works fine, but this time the online version produces a file with duplicated messages
Any idea what might be misconfigured?
I tried to configure the logger
In a function, that is called only once per session.
Thanks for your help!