So you have two computers in the same building, and you want them to share the same synchronised folder, communicating directly with each other.
This is incredibly easy to set up with the git annex assistant.
Let's say the two computers are your computer and your friend's computer. We'll start on your computer, where you open up your git annex dashboard.
*click*
*click*
Now the hard bit. You have to think up a secret phrase, and type it in, (and perhaps get the spelling correct).
Now your computer is in pairing mode. When your friend looks at her git annex dashboard, she sees something like this.
*click*
Now it's up to you to let her know what the secret is. As soon as she enters it, both your computers will be paired, and will begin to sync their git-annex folders. Just like that you can share files.
Something to keep in mind, especially if pairing doesn't seem to be working, is that the two computers need to be on the same network for this pairing process to work. Sometimes a building will have more than one network inside it, and you'll need to connect them both to the same one. Make sure the wireless network name is the same, or that they're both plugged into the same router.
Also, the file sharing set up by this pairing only works when both computers are on the same network. If you go on a trip, any files you edit will not be visible to your friend until you get back.
To get around this, you'll often also want to set up jabber pairing, and a server in the cloud, which they can use to exchange files while away.
And also, you can pair with as many other computers as you like, not just one!
What does pairing actually do behind the scenes?
It ensures that both repositories have correctly configured remotes pointing to each other. If you have already configured this manually, you do not need to perform pairing.
I'm trying to get local pairing working between two local machines (same switch, both connected via cat5 cables) and they're not seeing each other, though I can happily ssh from one box to the other.
In order to eliminate possible sources of problems, I tried these insecure settings:
-A INPUT -j ACCEPT
to the top of my firewall rulespassword
as the shared secretbut I still can't get past "pairing in progress" when pairing with a "Local computer".
Is there any way to get information as to where the two machines are failing to see one another?
Local pairing uses UDP port 55556. This is sent to multicast address 224.0.0.251 (same used by Avahi).
(You also need TCP port 22 open for ssh.)
I hadn't thought of ssh. So here's what I've got now:
-A INPUT -d 224.0.0.251/32 -p udp --dport 55556 -j ACCEPT
git annex webapp
is running as userfrancois
on both machinesopenssh-server
running on port 22 and its firewall allows desktop to connectopenssh-server
running on port 22 and its firewall allows the whole internal network to connect~/.ssh/authorized_keys
on desktop and ssh'ing works~/.ssh/authorized_keys
on laptop (is that required?)password
as a pairing key just to rule out any typos thereI don't see anything in the git-annex log on both of these machines. There's just a bunch of key generation stuff and then the last line is "Pairing in progress".
It turns out that my internal network had badly broken IPv6 configs between the boxes. That was interfering with the multicast packets but not with anything else since all of my other internal traffic is over IPv4.
Getting rid of these static IPv6 addresses has solved my problem. Local pairing is now working as advertised :)