Utilities/Zeroconf.app: Use dns-sd instead of avahi-browse #57
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- This will make it easier to write unit tests later. - This is consistent with the example set in Utilities/Calculator.app. - ./Zeroconf is now just a shell script pointing to the Python application.
In Python 2, there were old-style classes (`class Foo:`) and new-style classes (`class Foo(object):`). This is not necessary in Python 3.
This means that the self.app.aboutToQuit signal will be processed, and the application can clean up after itself.
A simple class representing a service, with some unused fields left out, and with no handle() method.
This will be useful when we want to remove services from the list or avoid adding duplicates.
It runs a command using QProcess and emits each line of the output through a pyqtSignal.
This class discovers services on the local network by running `dns-sd`.
This means the tool no longer leaves several `dns-sd` processes running in the background.
The recently added/modified classes behave differently from the old ones - so hook things up.
I don't know how to remove a PyQt5 widget entirely, so I used setHidden(true).
- self.services changed slightly in the previous commit, so the method has been updated to handle that. - DRY.
Preferences/Sharing.app also depends on Avahi because it uses Utilities/Preferences/Sharing.app/Resources/sharing.py Lines 159 to 160 in ce1bb2f Though, if I'll also note that |
This is a very interesting aspect which I did not know before, I was assuming that it is an either-or. At least Avahi had given me some messages to that end back when I was also experimenting with mDNSResponder/dns-sd, with the result that gvfs did not show network shares in Filer anymore. I will need to do more testing (using Live systems so that I don't break my installed system). Do you think you could implement something like #1 (comment)? |
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Note to self: Consider rewrite in Qt/C++ with https://github.com/nitroshare/qmdnsengine. This one is known to work even though avahi is running on the system (but does not need it). |
Hi!
First of all: I did all this work on a macOS desktop. I suspect everything will work on FreeBSD/hello (FreeBSD's mDNSResponder package comes from Apple), but I don't have a spare machine to experiment with right now.
Anyway, here's a PR that removes one dependency on Avahi from hello. Avahi depends on D-Bus, and D-Bus is unwelcome on hello.
avahi-browseoutputs all the relevant information when provided one set of flags. However thedns-sdtool in the mDNSResponder package requires several invocations to provide the same invocation so the Zeroconf.app tool has become a little more complex.Keeping with the spirit of hello, the whole application is still in one file. However I did add a couple of unit tests in separate files (
Resources/CommandReader_test.pyandResources/ZeroconfService_test.py).Testing
Install and setup mDNSResponder:
sudo pkg install mDNSResponder mDNSResponder_nsssudo vi /etc/nsswitch.confmdnsto the end of thehosts:linesudo sysrc mdnsd_enable=YESsudo service mdnsd startYou can run the application with the
Utilities/Zeroconf.app/Zeroconfscript, or runpython3 Utilities/Zeroconf.app/Resources/zeroconf.py.You can advertise a new service with this command (and take away the new service with Ctrl-C):
Hope this is useful. Thanks!