Valid point. Makes sense to drive this decision from the user and the framework.
On Tue, Oct 11, 2016 at 9:32 PM, Jie Yu <yujie....@gmail.com> wrote: > > > > While I believe this particular logic of setting LIBPROCESS_ADVERTISE_IP > > to agent IP can be done in the agent (it could look at the port mapping > > as well) > > > What if there are multiple port mappings? How can the agent decide which > port to be used as LIBPROCESS_ADVERTISE_PORT? > > On Tue, Oct 11, 2016 at 9:27 PM, Avinash Sridharan <avin...@mesosphere.io> > wrote: > > > Definitely a +1 for executor binding to 0.0.0.0, instead of doing a > > `gethostname` and `getaddrinfo`. But I am assuming this semantics would > > kick in only if LIBPROCESS_IP is not set, which should be the norm. > > > > +1 for LIBPROCESS_ADVERTISE_IP and LIBPROCESS_ADVERTISE_PORT and the onus > > being on the frameworks to set these variables. I guess the framework can > > set the LIBPROCESS_ADVERTISE_IP to the agent IP and > > LIBPROCESS_ADVERTISE_PORT to the host port when it specifies a > > port-mapping. While I believe this particular logic of > > setting LIBPROCESS_ADVERTISE_IP to agent IP can be done in the agent (it > > could look at the port mapping as well), when to actually set these > > variables (whether the executors even need to advertise their IP > addresses, > > is a decision that the Frameworks should be privy too and not left to the > > agent. > > > > On Tue, Oct 11, 2016 at 7:31 PM, haosdent <haosd...@gmail.com> wrote: > > > > > > libprocess should always bind to 0.0.0.0 > > > + 1 for this > > > > > > On Wed, Oct 12, 2016 at 2:33 AM, Jie Yu <yujie....@gmail.com> wrote: > > > > > > > Hi folks, > > > > > > > > I was in the process of cleaning up some tech debt related to env > > > variables > > > > in our code base. I created an epic ticket > > > > <https://issues.apache.org/jira/browse/MESOS-6341> to track. I > > searched > > > > relevant tickets fired previously, and found MESOS-3740 > > > > <https://issues.apache.org/jira/browse/MESOS-3740>. I did some > digging > > > on > > > > how we handle LIBPROCESS_IP currently, and here are my findings: > > > > > > > > 1) We always set LIBPROCESS_IP in the executor environment variables: > > > > https://github.com/apache/mesos/blob/master/src/slave/ > > > > slave.cpp#L6793-L6796 > > > > > > > > This is not an issue for an executor that runs on host network. > > However, > > > if > > > > the executor wants to run on non-host network (e.g., overlay), this > > might > > > > be problematic, because libprocess for the executor will try to bind > to > > > > LIBPROCESS_IP, but the IP is not valid inside the container. > > > > > > > > 2) As mentioned in MESOS-3740 > > > > <https://issues.apache.org/jira/browse/MESOS-3740>, some user wants > to > > > run > > > > a Mesos framework in a Mesos container. The old style framework > driver > > > > assumes a 2 way communication channel between the framework and the > > Mesos > > > > master. In order for the master to reach the framework running > inside a > > > > Mesos container, the framework's libprocess should advertise its ip > and > > > > port properly. This problem gets tricky because the networking for > the > > > > Mesos container: > > > > > > > > 2.a) If the container uses host network, libprocess should bind to > > > 0.0.0.0, > > > > and advertise itself using the agent ip and the relevant port > > > > 2.b) If the container has a routable ip (e.g., using calico or > > overlay), > > > > libprocess should still bind to 0.0.0.0, and advertise itself using > the > > > > container ip and the relevant port. Currently, it binds to agent ip > > > (which > > > > will fail), and advertise itself using agnet ip and the port in the > > > > container (which will fail as well) > > > > 2.c) If the container has a private ip (e.g., bridge), libprocess > > should > > > > still bind to 0.0.0.0, and advertise itself using the agent ip and > > > _mapped_ > > > > host port. Currently, it binds to agent ip (which will fail), and > > > advertise > > > > itself using agent ip and the port in the container (which will fail > as > > > > well) > > > > > > > > Therefore, the workaround > > > > <https://github.com/mesosphere/mesos/commit/ > > > b9c622b53b3ffcc27911fcdcefc37a > > > > 52ebe33bdd> > > > > suggested in MESOS-3740 <https://issues.apache.org/ > > > jira/browse/MESOS-3740> > > > > is not ideal. It does not consider 2.b) and 2.c) > > > > > > > > Libprocess now supports both LIBPROCESS_IP and > LIBPROCESS_ADVERTISE_IP > > so > > > > the bind address does not have to be the address that is being > > > advertised. > > > > > > > > For the 2.c) case, Mesos don't have a way to determine the advertise > > port > > > > (mapped port). This information is only known to the framework (which > > > host > > > > port it'll use to serve as the mapped port for the libprocess). > > > > > > > > Given that, I think Mesos should not bindly set LIBPROCESS_IP to > agent > > IP > > > > in executor environment variables. Framework should be the one that > > sets > > > > LIBPROCESS_ADVERTISE_IP and LIBPROCESS_ADVERTISE_PORT appropriately > if > > it > > > > tries to launch another Mesos framework so that Master can reach the > > new > > > > framework. If the framework just wants to launch a regular container > > that > > > > does not depends on libprocess, it should simply not set these env > > > > variables. > > > > > > > > Also, I think libprocess should always bind to 0.0.0.0, rather than > > > doing a > > > > hostname lookup and bind to the IP found for the hostname. > > > > LIBPROCESS_ADVERTISE_IP can be used to overwrite the ip address it > > wants > > > to > > > > advertise to peers. If that's not specified, it'll try to do a > hostname > > > > lookup to guess a routable ip. > > > > > > > > Thoughts? > > > > - Jie > > > > > > > > > > > > > > > > -- > > > Best Regards, > > > Haosdent Huang > > > > > > > > > > > -- > > Avinash Sridharan, Mesosphere > > +1 (323) 702 5245 > > > -- Avinash Sridharan, Mesosphere +1 (323) 702 5245
