What is the correct approach to refresh a running production environment

Question

I am not showing much code here , but I have a requirement to fix. We have file with over 100 function that are being used in various shell scripts in production. We have named it as.

functions.sh

Up-till now each script call this "functions.sh" file in it so it can access the updated function. Like this

#!/bin/bash
# comment
# comment
# Comment

./path/function.sh

echo "Date" > logging()
..

Now we have been asked to get rid of this call :

./path/function.sh

from scripts that will be developed in future. (so that more such files can be added) & make sure latest functions are automatically refreshed in environment as soon as new "functions.sh" is deployed to production and any scripts can use the function defined in them directly . Shall I just call it in .bashrc file as

~/.functions.sh 

or is there anything else we have to do , keeping in mind scripts will be executed in non-interactive mode through crontab. ( all scripts are bash scripts ) any help is appreciated.

Thanks

Answer 1

Read https://www.gnu.org/software/bash/manual/bash.html#Bash-Startup-Files

For non-interactive shells (such as running a script via cron), bash uses the BASH_ENV environment variable as the name of a file to source.

So, for maximum flexibility, you can do something like this:

/some/path
├── functions.d
│   ├── func1.sh
│   ├── func2.sh
│   ├── ...
│   └── funcN.sh
└── functions.sh

And functions.sh could be

#!/usr/bin/env bash
func_dir="${BASH_SOURCE[0]%/*}/functions.d"
if [[ -d "$func_dir" ]]; then
    for f in "$func_dir"/*.sh; do
        if [[ -r "$f" ]]; then
            . "$f"
        fi
    done
fi

In your crontab file, add

BASH_ENV=/some/path/functions.sh

So all you have to do is add a .sh file to that directory, and your cron scripts will source it.

This gives you the flexibility to create files each containing just a single function definition. No more giant library files.