• David Johnson's avatar
    Ubuntu 15 support. · 2baf7655
    David Johnson authored
    Similar to Ubuntu 14, but new and different UIDs, and...
    systemd!  systemd has made it into Ubuntu.  This affects our control net
    discovery.  Our /etc/network/interfaces hack marks eth[0-9] as "auto".
    New Ubuntu versions have systemd (or upstart, if your Ubuntu 15 uses
    that -- our images will not) job that waits for any interfaces marked
    auto to come up, and doesn't timeout for 2 mins.  This doesn't work for
    us, because our use of auto is abuse :).
    So, we enter a new level of abuse.  We change the systemd unit
    dependencies, making the network-online.target service want (depend on)
    our special ifup-wait-emulab-cnet.service (which looks for /run/cnet to
    get written), instead of on ifup-wait-all-auto.service.  This means
    network-online.target happens as soon as the control net is up, which is
    the primary thing we're concerned about.
    Now, if experimenters would ever add their own special "auto" interfaces
    to /etc/network/interfaces, the rest of the startup scripts that depend
    on network-online.target could possibly race (although you would think
    that our control net discovery will be slower than any static
    But for now, this solution appealed more that "faking" that eth[0-9] are
    all up by writing the right files --- or by finding a better mechanism
    instead of abusing "auto".
configure.ac 8.76 KB