[Dsg-halla_gas] [EXTERNAL] Re: Login instructions and remote monitoring

[Marc Mcmullen]

I'll give this a try. VNC is already enabled on the RP.  I just needed a work around because I didn't know if there was a computer on that subnet with VNC available.

Thanks,
Marc
________________________________
From: Brad Sawatzky <brads at jlab.org>
Sent: Monday, December 21, 2020 2:43 PM
To: Marc Mcmullen <mcmullen at jlab.org>
Cc: dsg-halla_gas at jlab.org <dsg-halla_gas at jlab.org>; Chuck Long <mlong at jlab.org>
Subject: [EXTERNAL] Re: [Dsg-halla_gas] Login instructions and remote monitoring

Hi Marc,

I not on vacation yet, but am (unfortunately) tied up in meetings all
afternoon.  Happy to chat Tuesday if you like.  I'll summarize my
approach below, FWIW.

The way I've done this in the past is to have the VNC server only bound
to 'localhost'.  This is very easy under linux, MacOS/Windows need to
  Linux:
    vncviewer -via user at host :1

  Windows/MacOS:
  - 'SSVNC' : client with automatic tunneling built in
  - Or open a terminal and establish the tunnel manually
      $ ssh -L 5901:localhost:5901 user at host
    - Then run the VNC client and connect to 'localhost:5901'
      $ open 'vnc://localhost:5901'  (MacOS terminal, for example)

The tunnel removes the valid security risks with 'raw' VNC access, and
allows people to still connect across VLANs firewalling.

-- Brad

On Mon, 21 Dec 2020, Marc Mcmullen wrote:

> Hi Brad,
> I have experimented with VNC, but there are some hoops to get around. Do you
> have a few minutes to chat? Not sure if you are on vacation.
> Thanks,
> Marc
>
> ----------------------------------------------------------------------------
>



> From: Brad Sawatzky <brads at jlab.org>
> Sent: Monday, December 21, 2020 2:18 PM
> To: Marc Mcmullen <mcmullen at jlab.org>
> Cc: dsg-halla_gas at jlab.org <dsg-halla_gas at jlab.org>; Chuck Long
> <mlong at jlab.org>
> Subject: [EXTERNAL] Re: [Dsg-halla_gas] Login instructions and remote
> monitoring
>
> Hi Marc,
>
> I would recommend running the GEM readout in a VNC session.  That would
> allow multiple people to view the screen at a time.  It would also allow
> for full remote operation of the GUI.   (That is, the software will run
> persistently within the VNC session, even if a remote user starts it,
> and will not die if the remote connection drops or someone else wants to
> view the GUI).
>
> -- Brad
>
> Oe Fri, 18 Dec 2020, Marc Mcmullen wrote:
>
> > Hi,
> > DSG has installed the GEM Gas Flow Readout single board computer
> (Raspberry
> > Pi). The software installed is prototype and will be updated in 2021.
> > Here are some important notes on monitoring:
> >
> >  1. It is best practice to remotely login using the instructions attached
> to
> >     this email to monitor the gas flow, even if you are local (at the
> lab).
> >     If you are at the gas distribution rack, please observe the flow by
> >     looking at the Flow Meter Panel in the rack.
> >
> >   1. logging in and running the display on the local Raspberry Pi monitor
> >      will prevent viewing the display remotely
> >   2. If the display is left on locally, the CSS program will have to be
> >      "killed" or the Raspberry pi will have to be rebooted (~ 2 minutes)
> and
> >      all software must be restarted (~ 2 minutes) per the instructions (on
> >      the desktop of the Raspberry Pi and in this email)
> >
> >  2. To remote monitor follow the instructions attached to this email. DSG
> >     has already started the monitoring program, if it is not running:
> >
> >   1. restart the software by following the attached instructions (also on
> >      the desktop of the Raspberry pi)
> >   2. send an email to the group and someone will restart the software
> >
> >  3. Only one person can remotely log into the Raspberry Pi at a time,
> >     logging in will disconnect someone who is already logged in, so please
> >     coordinate with each other via email and disconnect by closing the
> >     Remote Desktop window when you are finished monitoring
> >
> > In future updates, DSG plans to make a web distribution for the prototype
> > software, allowing multiple users to monitor the CSS screen.
> > Finally, EPICS will be used to monitor gas flow during hall operations.
> > Regards,
> > Marc
>
--
Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
Ph: 757-269-5947  -<>-  Fax: 757-269-5235  -<>- Pager: brads-page at jlab.org
The most exciting phrase to hear in science, the one that heralds new
  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov
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