How do I configure Ubuntu one on a server?

Ubuntu One requires X and a dbus session. You can make it work headless following these instructions: https://wiki.ubuntu.com/UbuntuOne/Headless

Running Ubuntu One in Headless Mode

1. Install ubuntuone-client package:

   sudo apt-get install ubuntuone-client 
   

2. Setup the user directories:

   mkdir -p ~/.config/ubuntuone ~/bin 
   

   If you did not have a ~/bin when you logged in, your path doesn't include it, to rectify run (or simply log out and in again and ubuntu will set it up for you):

   export PATH=$HOME/bin:$PATH 
   

3. Obtain OAuth key for your account:

   cd /tmp
   wget http://people.canonical.com/~roman.yepishev/us/ubuntuone-sso-login.py
   python ubuntuone-sso-login.py
   Ubuntu SSO Login: **your Ubuntu SSO Login**
   Password: **your Ubuntu SSO Password**
   oauth=hPQWPsH:rhOokmNiRuuoiHe... 
   

4. Copy the line starting with oauth= to ~/.config/ubuntuone/syncdaemon.conf as oauth parameter under main section (this is ini-style file):

   [__main__]
   oauth=hPQWPsH:rhOokmNiRuuoiHe... 
   

   (you might just as well remove the first two fields in the oauth-string, ie oath=aaa:bbb:ccc:ddd => oath=ccc:ddd )

5. Download the u1sdtool wrapper which will start dbus when needed. By default Ubuntu adds ~/bin/ to your path, so when you run u1sdtool, you will be running the wrapper.

   wget http://people.canonical.com/~roman.yepishev/us/u1sdtool-wrapper -O ~/bin/u1sdtool
   chmod +x ~/bin/u1sdtool 
   

6. Start Ubuntu One, check Ubuntu One status and connect (starting from Oneiric Ubuntu One is connecting automatically when started):

   u1sdtool --start
   u1sdtool --status
   State: READY
     connection: Not User With Network
     description: ready to connect
     is_connected: False
     is_error: False
     is_online: False
     queues: IDLE
   u1sdtool --connect 
   

   If you are greeted with a with the display manager error, try prepending u1sdtool with ~/bin/ since the most probable cause are the aforementioned issue with your PATH.

7. Look at the string followed by "connection". If it says "Not User" your credentials haven't been processed, stop and start the syncdaemon:

   u1sdtool --quit
   u1sdtool --start
   

   and try again.

   If it says "No network", it claims you're not connected to the internet, and I had to fix this by installing nmcli (sudo apt-get install network-manager --no-install-recommends) and fiddle with nmcli. You might need to install consolekit, too.

8. Start adding files to ~/Ubuntu One directory and u1sdtool to add UDF, publish the files etc.

I just had this issue.

Turns out it was because I was connecting with screen+ssh.

http://www.rootninja.com/dbus-session-bus-address-with-applications-using-ssh/

Running this solves the issue for me:

eval `dbus-launch --sh-syntax`