Running two separate servers (was Re: venv questions)

[gene heskett]

On 8/29/22 23:22, Chris Angelico wrote:
> On Tue, 30 Aug 2022 at 12:59, gene heskett <gheskett at shentel.net> wrote:
>> But that might create another problem. how to differentiate the servers,
>> both of which
>> will want to use localhost:5000 to serve up their web pages we run
>> things with.
>>
>> Suggested solutions?
> This is nothing to do with venvs, so I'm forking the thread.
>
> By far the easiest way to differentiate them is to NOT have them both
> on localhost:5000. Depending on how you invoke the servers, you should
> be able to find a way to configure one (or both) of them to a
> different port; common methods include a "--port" argument, setting
> the PORT environment variable, and poking in the code to find the
> number 5000 and changing it to some other value.
>
> (Less common methods include poking in ctypes to find the number 5000
> and changing it to some other value. Mentioned only because I realise
> the alternative interpretation of my previous comment.)
>
> Another method would be to change the "localhost" part. The standard
> for IP addresses is that 127.x.y.z means localhost, regardless of what
> x, y, and z are; so you could have one of them bind to 127.0.0.2 and
> the other to 127.0.0.3, which you could then use in your browser the
> same way (http://127.0.0.2:5000/ and http://127.0.0.3:5000/
> respectively).
>
> But if you can't change anything else, you'll have to make the two
> processes cooperate in some way, or worst case, just make sure you
> shut one down before you start the other up.
>
> ChrisA
That is a limitation I'd druther not have to deal with Chris. I want two
separate octoprint servers running with no interaction between them.

So I'm thinking of venv's named rock64prusa, and rock64ender5+, each with
"port#" on my local net. So chromium could have two tabs open, one to
localhost:5000 and one to localhost:5001, totally independent of each other.

I already have that in my /etc/hosts file. No dns resolving involved.

And from snooping just now, the port # is set it /etc/default/octoprint, 
so copy
/etc/default/octoprint to octoprint-prusa, and to octoprint-ender5+, do 
the same in
/etc/init.d, and change the port # & venv name  in the -ender5+ version. 
Then
reconfigure the ender5+ version to drive that printer.

With the venv isolation, it should work, with a browser tab at 
localhost:5000 and
another tab at localhost:5001, each pointing at its own directory tree 
in /home/gene.

The separation is also because of the way linux finds usb facilities, the
prusa is always /dev/ttyACM0 and the ender5+ is almost always /dev/ttyUSB0.
in this case I've a 4 port usb hub with port disabling switches plugged
into the rock64.

One of the things I want to try is plugging in a startech usb3 to sata 
adapter
with a small SSD plugged into it, and move the /tmp directory off that poor
u-sd card to prolong its life.

And each with its own input buffer that cura can see from here. The new 
cura 5.1
has its own set of problems, not being able to see octoprints defaulted 
input buffer
hidden behind a dotted directory being a starter, toss in that it has no 
way to look at
.. and that requires a user session of mc just to move the gcode 
produced to be printed
from a local dir here to the input buffer of that instance of octoprint.

Back at this come daylight.  Thank you Chris.

Cheers, Gene Heskett.
-- 
"There are four boxes to be used in defense of liberty:
  soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
  - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>