On Tue, Mar 29, 2016 at 3:26 PM, Bill Farner <wfar...@apache.org> wrote:
> If i'm understanding you correctly, that doesn't address preventing users > from reading the credentials though. > It does: Say: /var/lib/aurora/creds 400 root And then if the CommandInfo has user: aurora (executor user as Steve suggested), it will get a copy of /var/lib/aurora/creds in its sandbox chowned to 400 aurora Now aurora's executor (thermos), launches a task in role www-data announcing for it using the cred. The www-data user will not be able to read the local sandbox 400 aurora creds. > On Tue, Mar 29, 2016 at 1:52 PM, John Sirois <jsir...@apache.org> wrote: > > > On Tue, Mar 29, 2016 at 2:31 PM, Steve Niemitz <sniem...@apache.org> > > wrote: > > > > > So maybe we add it, but don't change the current default behavior? > > > > > > > Could we use the CommandInfo.uris [1] to solve this? IE: the scheduler > > would need to learn the credential file path, and with that knowledge, > the > > local mesos (root) readable credential file could be specified as a uir > > dependency for all launched executors (or bare commands). IIUC, if the > URI > > if a file:// the local secured credentails file will be copied into the > > sandbox where it can be read by the executor (as aurora). > > > > [1] > > > https://github.com/apache/mesos/blob/master/include/mesos/mesos.proto#L422 > > > > > > > > > > On Tue, Mar 29, 2016 at 4:26 PM, Bill Farner <wfar...@apache.org> > wrote: > > > > > > > I'm in favor of moving forward. There's no requirement to use the > > > > Announcer, and a non-root executor seems like a useful option. > > > > > > > > On Tue, Mar 29, 2016 at 1:00 PM, Steve Niemitz <sniem...@apache.org> > > > > wrote: > > > > > > > > > Makes sense, I guess it can be up to the cluster operator which > model > > > to > > > > > choose. Is there any interest in the feature I proposed or should > I > > > just > > > > > drop it? It's not a lot of code, but also it's not a requirement > for > > > > > anything we're working on either (the docker stuff however, is). > > > > > > > > > > On Tue, Mar 29, 2016 at 1:39 PM, Bill Farner <wfar...@apache.org> > > > wrote: > > > > > > > > > > > That's correct - those credentials should require privileged > > access. > > > > > > > > > > > > On Tue, Mar 29, 2016 at 10:25 AM, Steve Niemitz < > > > > > > sniem...@twitter.com.invalid> wrote: > > > > > > > > > > > > > Re: ZK credential files, thats an interesting issue, I assume > you > > > > don't > > > > > > > want the role user to be able to read it either, and only root > or > > > > some > > > > > > > other privileged user? > > > > > > > > > > > > > > On Tue, Mar 29, 2016 at 12:14 PM, Erb, Stephan < > > > > > > > stephan....@blue-yonder.com> > > > > > > > wrote: > > > > > > > > > > > > > > > I am in favor of your proposal. We offer less attack surface > if > > > the > > > > > > > > executor is not running as root. > > > > > > > > > > > > > > > > Interesting though, this introduces another security problem: > > The > > > > > > > > credentials file in the incoming Zookeeper ACL patch ( > > > > > > > > https://reviews.apache.org/r/45042/) will have to be > readable > > by > > > > > > > > everyone. That feels a little bit like being back to square > > one. > > > > > > > > ________________________________________ > > > > > > > > From: Steve Niemitz <sniem...@apache.org> > > > > > > > > Sent: Tuesday, March 29, 2016 17:34 > > > > > > > > To: dev@aurora.apache.org > > > > > > > > Subject: Looking for feedback - Setting CommandInfo.user by > > > default > > > > > > when > > > > > > > > launching tasks. > > > > > > > > > > > > > > > > I've been working on some changes to how aurora submits tasks > > to > > > > > mesos, > > > > > > > > specifically around Docker tasks, but I'd also like to see > how > > > > people > > > > > > > feel > > > > > > > > about making it more general. > > > > > > > > > > > > > > > > Currently, when Aurora submits a task to mesos, it does NOT > set > > > > > > > > command.user on the ExecutorInfo, this means that mesos > > > configures > > > > > the > > > > > > > > sandbox (mesos sandbox that is) as root, and launches the > > > executor > > > > > > > > (thermos_executor in our case) as root as well. > > > > > > > > > > > > > > > > What then happens is that the executor then chown()s the > > sandbox > > > it > > > > > > > creates > > > > > > > > to the aurora role/user, and also setuid()s the runners it > > forks > > > to > > > > > > that > > > > > > > > role/user. However, the executor itself is still running as > > > root. > > > > > > > > > > > > > > > > My proposal / change is to set command.user to the aurora > role > > by > > > > > > > default, > > > > > > > > which will cause the executor to run as that user. I've > tested > > > > this > > > > > > > > already, and no changes are needed to the executor, it will > > still > > > > try > > > > > > to > > > > > > > > chown the sandbox (which is fine since it already owns it), > and > > > > > > setuid() > > > > > > > > the runners it forks (again, fine, since they're already > > running > > > as > > > > > > that > > > > > > > > user). > > > > > > > > > > > > > > > > *The controversial part of this* however is I'd like to > enable > > > this > > > > > > > > behavior BY DEFAULT, and allow disabling it (reverting to the > > > > current > > > > > > > > behavior now) via a flag to the scheduler. My reasoning here > > is > > > > two > > > > > > > fold. > > > > > > > > 1) It's a more secure default, preventing a compromised > > executor > > > > > from > > > > > > > > doing things it shouldn't, and 2) we already have a lot of > > "flag > > > > > > bloat", > > > > > > > > and flags are hard enough to discover as they are. However, > I > > do > > > > > > believe > > > > > > > > this should be considered as a "breaking change", > particularly > > > > > because > > > > > > of > > > > > > > > finicky PEX extraction for the executor. > > > > > > > > > > > > > > > > I'd like to hear people's thoughts on this. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- John Sirois 303-512-3301
