Re: Simple way for web to execute root shell script.

On 24/05/2025 03:13, Rich wrote:

In comp.os.linux.misc The Natural Philosopher <tnp@invalid.invalid> wrote:

On 23/05/2025 19:44, Rich wrote:

In comp.os.linux.misc The Natural Philosopher <tnp@invalid.invalid> wrote:

I have a shell script that monitors hardware stuff - it needs to run
as root and be called by Apache as user www.
>
   Bookworm linux on a Pi4.
>
Its all inside a domestic firewall so security is not a huge issue.
What is the quickest and simplest solution to this?

>
You've been given lots of options already.  But not this one.
>
What "hardware stuff" is it monitoring?  If it is reading files in
/proc and/or /sys to obtain its "data" then another alternative would
be to setup /proc and /sys to be mounted group or world readable (or to
reset permissions on the necessary files via a rc.local boot script to
group or world readable).  That would let the script "monitor" without
being root.  Then you could even convert the script into a CGI script
(which Apache is more than able to execute, and doing so for minimal
text output involves the script outputting a handful of HTTP headers
before the monitor data) and get your "monitoring data" back via
Apache.
>

Sadly the data is not available in /sys or /proc AFAIK.

 Yeah, at least the smart data is not (as far as I am aware) available
via /proc or /sys.
 

No. I didnt think so either. :-(
Neither I think is the vcgencmd stuff.
Probably disk and network data is in there somewhere.

Another option.  You could setup a cronjob, as root, to run your script
on some periodic basis (once per minute, every 10 minutes, etc.) and
save the results into a file that is readable via the 'www' user (or to
save the info directly into a file in the Apache htdocs hierarchy from
where you want to retreive it).
 Then you can 'pull' the data via Apache from that file.
 

I've used that approach elsewhere, But it means more storage.

You'd have data that is up to date as of the last run of the script,
but you would not have the "exactly now it is Y" aspect (unless your
AJAX pulled just after a cronjob run *and* you were watching the
'meters' at that very moment).
 You could even include a "date" as the first line, so you could see if
something got hung by the time value being too far in the past.
 

Could do, yes. But this way I get up to the second data.
Essentially this is pushing the Pi 4 a bit to its limits and I want to be able to do a snap inspection.
--
    "Fanaticism consists in redoubling your effort when you have forgotten your aim."
  George Santayana