[squeak-dev] Controlling a headless server Squeak through VNC

David T. Lewis lewis at mail.msen.com
Sun Dec 4 20:05:07 UTC 2022


Hi Bernhard,

The two dialogs for entering user name and password are for the demonstration
application that comes with the Seaside distribution. You can enter anything
you like for these, I usually just enter 'admin' and 'password' to get through
the dialogs.

The third dialog concerning 'data.obj does not exist' is something
that I do not recognize. I don't see it on Linux so I am guessing
that it may be related to the operating system. I don't have a Mac,
but maybe someone else could try it to confirm?

I'm afraid that there is a fair amount of Linux-specific stuff that
has crept into the the SqueakSource code base over time. Most likely
there is something in the SqueakSource initialization code is trying
to find a serialized copy of the repository, but I can't say why
you are hitting that code path on macOS.

Dave


On Sun, Dec 04, 2022 at 07:36:57PM +0000, Bernhard Pieber wrote:
> Hi Dave,
> 
> Thanks for providing the instructions. I just tried them on Squeak6.1alpha-22300-64bit on macOS 12.6.1.
> 
> When loading update.sscom-dtl.5.mcm two modal dialogs are shown:
> 
> I entered admin and password. Then I get this:
> 
> Any idea what I might be missing?
> 
> Cheers,
> Bernhard
> 
> > Am 03.12.2022 um 22:03 schrieb David T. Lewis <lewis at mail.msen.com>:
> >
> > During a recent board discussion, Tim asked about experiences in using VNC
> > to control server images. There are various ways to do this, but here is how
> > it is done for the https://squeaksource.com server. The easiest way to see
> > how it works is to try it out on your own computer, so here is what to do:
> >
> > - Start with a fresh Squeak image.
> > - Open a Monticello Browser, and add repository http://source.squeak.org/ss.
> > - Open the repository and navigate to category update.sscom.
> > - Select update.sscom-dtl.5.mcm and load it.
> >
> > When loading is complete, you will see a notifier saying that SqueakSource
> > is running on port 8888, as well as a pinnable morph for controlling the
> > RFBServer (for VNC connections).
> >
> > Pin the RFB control morph so that it stays active. If you close it by
> > accident, do "RFBServer menu openInWorld" to get it back.
> >
> > Save the image once and restart it to make sure the startup initialization
> > is working.
> >
> > You can now open a web browser on http://localhost:8888 to connect to
> > the SqueakSource web interface. Only one account will be present in the
> > repository, this is your administrative user with user name 'admin' and
> > password 'password'. Changing that password (from the web interface) is
> > a good idea.
> >
> > The following will work only on Unix/Linux/OSX:
> >
> > In the RFBServer menu, in the passwords menu, select "allow empty passwords"
> >
> > In a terminal window (outside of Squeak), identify the pid of the Squeak VM
> > process (pgrep -l squeak).
> >
> > From the terminal, send a SIGUSR2 signal to the VM process. If the Squeak
> > VM pid is 1234, then the command is "kill -SIGUSR2 1234".
> >
> > Back in the Squeak image, you will see the VNC control change from
> > "RFBServer (stopped)" to "RFBServer :1" to indicate that it is accepting
> > VNC connections on display number 1. It will stay in this state for the
> > next 60 seconds.
> >
> > From a VNC client program running on the local machine, connect to
> > localhost:1, and you should have an active connection to the Squeak image.
> >
> > If you want to run your SqueakSource image on another server, run the
> > VM with -vm-display-null and use ssh port forwarding if needed to access
> > the VNC ports.
> >
> > For example, I have a unix account on the server that hosts squeaksource.com.
> > When I want to open the running SqueakSource image through VNC, I first
> > log in to the Linux server with a command like this (except that 10.1.2.3
> > is not the real address that we are using).
> >
> > $ ssh -L8888:localhost:8888 -L5900:localhost:5900 -L5901:localhost:5901 10.1.2.3
> >
> > Once logged in, I locate the Squeak VM process and send SIGUSR2 to it. I keep
> > the login session open to handle the port forwarding while I use VNC.
> >
> > Then back on my local computer, I open a VNC connection to localhost:1 to
> > get a connection to the running image. This step needs to be done within 60
> > seconds of the SIGUSR2, after than no further connections will be accepted.
> >
> > I used to use a VNC password (settable from the RFBServer menu) but I decided
> > that it was too much hassle given the 60 second connection enablement window,
> > which can only be started by someone with login access to the server and
> > sufficient privilege to send signals to the VM process.
> >
> > If you want to copy any of these ideas for use in some other Squeak server
> > application, the interesting bits are in class SSImageInit, especially
> > SSImageInit class>>enableFRBServerOnSigUsr2.
> >
> > I should note that RFBServer is written by Ian Piumarta. I don't recall
> > where it was originally hosted, but a copy of RFB-ikp.8.mcz is in our
> > source.squeak.org/ss repository, along with later updates that are currently
> > in use for SqueakSource.
> >
> > Dave
> 



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