macOS Command-Line – Launchd Listening on Port 4444

command linelaunchdmacosopen source

the lsof command tells me launchd is listening on port 4444:

$ sudo lsof -i tcp:4444

COMMAND PID USER   FD   TYPE           DEVICE SIZE/OFF NODE NAME
launchd   1 root   32u  IPv4 0xfe4e7e9bb5c1a5      0t0  TCP localhost:krb524 (LISTEN)
launchd   1 root   46u  IPv4 0xfe4e7e9bb5c1a5      0t0  TCP localhost:krb524 (LISTEN)

I'm trying to set up a Selenium (https://www.seleniumhq.org/) Server whose default port is 4444 – I realise I could change Selenium's port, but I don't recall having this clash on Macs previously (I guess prior to Tiger)

Is it possible/viable to have launchd run on a different port?

EDIT:
I found the following info by searching which plist files refer to port 4444 – it shows that it's part of the Server configuration. The Wiki feature of Server is currently turned OFF. Is it safe to edit this file to change the port setting?

/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.auth.plist:19: http://localhost:4444/auth
/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.changepassword.plist:19: http://localhost:4444/changepassword
/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.collabd.plist:24: http://localhost:4444/svc
/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.collabd.plist:33: http://localhost:4444/streams/activity
/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.wiki.plist:24: http://localhost:4444/preview
/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.wiki.plist:33: http://localhost:4444/files
/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.wiki.plist:42: http://localhost:4444/upload_file
/Applications/Server.app/Contents/ServerRoot/private/etc/apache2/webapps/com.apple.webapp.wiki.plist:51: http://localhost:4444/app-context/wiki

Best Answer

Yes. Changing port is as simple as running it with a command line override:

selenium-server -port 4455

The above would try listening on port 4455 instead of 4444

Changing launchd is a little more work since you need to locate the exact file on the filesystem that it got the directions to listen on 4444.

Here is a nice write up of one such way to configure selenium to use port 4444

So, you’d need to edit the plist that controls the launch. I would recommend using homebrew to install this:

mac:dev me$ brew install selenium-server-standalone
==> Downloading https://selenium-release.storage.googleapis.com/3.11/selenium-server-standalone-3.11.0.jar
######################################################################## 100.0%
==> Caveats
To have launchd start selenium-server-standalone now and restart at login:
  brew services start selenium-server-standalone
Or, if you don't want/need a background service you can just run:
  selenium-server -port 4444
==> Summary
?  /usr/local/Cellar/selenium-server-standalone/3.11.0: 5 files, 22.3MB, built in 7 seconds
mac:dev me$ selenium-server -port 4455

You can see that you can override the port from this selenium server from the command line or edit ~/Library/LaunchAgents/homebrew.mxcl.selenium-server-standalone.plist to change these two lines that control the default port:

<string>-port</string>
<string>4444</string>

once you save the change, cycle the service using:

brew services restart selenium-server-standalone
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