[SOLVED] Post real time output to Slack with bash script

Post real time output to Slack with bash script

I have a python script that I am executing with cron job. This script generates some output while executing and I wish to post it to Slack channel in real time.

Here is a bash script that I have:

#!/bin/bash

log_file=logs_$(date '+\%Y-\%m-\%d_\%H:\%M').txt

cd /path/to/script/run.py > /path/to/logs/${log_file} 2>&1 

cat /path/to/logs/${log_file} | while read LINE; do
  (echo "$LINE" | grep -e "Message" ) && curl -X POST --silent --data-urlencode \
    "payload={\"text\": \"$(echo $LINE | sed "s/\"/'/g")\"}" "https://hooks.slack.com/services/xxxxxx";
done

This scrip works but it of course posts all messages to slack once the python script has already been executed. Is there any way I could configure it so that messages would be sent to Slack in real time while the python script is still being executed?

Solution

You may be able to read the output from your run.py script via process substitution:

#!/bin/bash

log_file=logs_$(date '+\%Y-\%m-\%d_\%H:\%M').txt

while read -r line ; do
    printf "%s\n" "$line"
    (grep -e "Message" <<< "$line") && curl -X POST --silent --data-urlencode \
        "payload={\"text\": \"$(echo $line | sed "s/\"/'/g")\"}" "https://hooks.slack.com/services/xxxxxx";
done < <(/path/to/script/run.py 2>&1) >> "$log_file"

It may also prove useful to paste your code into shellcheck.net and have a look at the suggested changes.