Sorry for the delay:
Two questions that we didn't see in the wiki:
1. Is there an expiration for delegation tokens? Renewal? How do we revoke them?
2. If we want to use delegation tokens for "do-as" (say, submit Storm
job as my user), we will need a producer for every job (we can't share
them between multiple jobs running on same node), since we only
authenticate when connecting. Is there a plan to change this for
delegation tokens, in order to allow multiple users with different
tokens to share a client?
Gwen
On Tue, May 3, 2016 at 9:12 AM, parth brahmbhatt
<brahmbhatt.pa...@gmail.com> wrote:
> Bumping this up one more time, can other committers review?
>
> Thanks
> Parth
>
> On Tue, Apr 26, 2016 at 9:07 AM, Harsha <ka...@harsha.io> wrote:
>
>> Parth,
>> Overall current design looks good to me. I am +1 on the KIP.
>>
>> Gwen , Jun can you review this as well.
>>
>> -Harsha
>>
>> On Tue, Apr 19, 2016, at 09:57 AM, parth brahmbhatt wrote:
>> > Thanks for review Jitendra.
>> >
>> > I don't like the idea of infinite lifetime but I see the Streaming use
>> > case. Even for Streaming use case I was hoping there will be some notion
>> > of
>> > master/driver that can get new delegation tokens at fixed interval and
>> > distribute to workers. If that is not the case for we can discuss
>> > delegation tokens renewing them self and the security implications of the
>> > same.
>> >
>> > I did not want clients to fetch tokens from zookeeper, overall I think
>> > its
>> > better if clients don't rely on our metadata store and I think we are
>> > moving in that direction with all the KIP-4 improvements. I chose
>> > zookeeper as in this case the client will still just talk to broker , its
>> > the brokers that will use zookeeper which we already do for a lot of
>> > other
>> > usecases + ease of development + and the ability so tokens will survive
>> > even a rolling restart/cluster failure. if a majority agrees the added
>> > complexity to have controller forwarding keys to all broker is justified
>> > as
>> > it provides tighter security , I am fine with that option too.
>> >
>> > Given zookeeper does not support SSL we can not store master keys in
>> > zookeeper as master keys will be exposed on wire. To support rotation
>> > without affecting current clients is something I need to put more thought
>> > in. My current proposal assumes the rotation will invalidate all current
>> > tokens.
>> >
>> > I request committers to also review and post their comments so we can
>> > make
>> > progress on this KIP.
>> >
>> > Thanks
>> > Parth
>> >
>> > On Tue, Apr 19, 2016 at 8:39 AM, Ashish Singh <asi...@cloudera.com>
>> > wrote:
>> >
>> > > On Mon, Apr 18, 2016 at 11:26 AM, Harsha <ka...@harsha.io> wrote:
>> > >
>> > > > Unifying the two discussion threads on this KIP.
>> > > >
>> > > > Here is the response from Jitendra
>> > > >
>> > > > "The need for a large number of clients that are running all over the
>> > > > cluster that authenticate with Kafka brokers, is very similar to the
>> > > > Hadoop use case of large number of tasks running across the cluster
>> that
>> > > > need authentication to Hdfs Namenode. Therefore, the delegation token
>> > > > approach does seem like a good fit for this use case as we have seen
>> it
>> > > > working at large scale in HDFS and YARN.
>> > > >
>> > > > The proposed design is very much inline with Hadoop approach. A few
>> > > > comments:
>> > > >
>> > > > 1) Why do you guys want to allow infinite renewable lifetime for a
>> > > > token? HDFS restricts a token to a max life time (default 7 days). A
>> > > > token's vulnerability is believed to increase with time.
>> > > >
>> > > I agree that having infinite lifetime might not be the best idea.
>> > >
>> > > >
>> > > > 2) As I understand the tokens are stored in zookeeper as well, and
>> can
>> > > > be updated there. This is clever as it can allow replacing the tokens
>> > > > once they run out of max life time, and clients can download new
>> tokens
>> > > > from zookeeper. It shouldn't be a big load on zookeeper as a client
>> will
>> > > > need to get a new token once in several days. In this approach you
>> don't
>> > > > need infinite lifetime on the token even for long running clients.
>> > > >
>> > > > 3) The token password are generated using a master key. The master
>> key
>> > > > should also be periodically changed. In Hadoop, the default renewal
>> > > > period is 1 day.?
>> > > >
>> > > IIUC, this will require brokers maintaining a list of X most recent
>> master
>> > > keys. This list will have to be persisted somewhere, as if a broker
>> goes
>> > > down it will have to get that list again and storing master keys on ZK
>> is
>> > > not the best idea. However, if a broker goes down then we have much
>> bigger
>> > > issue to deal with and client can always re-authenticate is such
>> events.
>> > >
>> > > Did you happen to take a look at other alternatives this list has
>> > > suggested?
>> > >
>> > > >
>> > > > Thanks for a thorough proposal, great work!"
>> > > >
>> > > >
>> > > >
>> > > > On Mon, Mar 7, 2016, at 10:28 PM, Gwen Shapira wrote:
>> > > > > Makes sense to me. Thanks!
>> > > > >
>> > > > > On Mon, Mar 7, 2016 at 9:25 PM, Harsha <ka...@harsha.io> wrote:
>> > > > > > It doesn't need any release vehicle but still the work can move
>> > > > forward.
>> > > > > > If anyone is interested in the KIP please do the review and
>> provide
>> > > the
>> > > > > > comments.
>> > > > > >
>> > > > > > -Harsha
>> > > > > >
>> > > > > > On Mon, Mar 7, 2016, at 04:59 PM, Ismael Juma wrote:
>> > > > > >> I agree that it would be good to have more time to review and
>> > > discuss
>> > > > > >> KIP-48.
>> > > > > >>
>> > > > > >> Ismael
>> > > > > >>
>> > > > > >> On Tue, Mar 8, 2016 at 12:55 AM, Gwen Shapira <
>> g...@confluent.io>
>> > > > wrote:
>> > > > > >>
>> > > > > >> > Hi Team,
>> > > > > >> >
>> > > > > >> > Since KIP-48 depends on KIP-43, which is already a bit of a
>> risk
>> > > for
>> > > > > >> > the next release - any chance we can delay delegation tokens
>> to
>> > > > Kafka
>> > > > > >> > 0.10.1?
>> > > > > >> > With the community working on a release every 3 month, this
>> is not
>> > > > a huge
>> > > > > >> > delay.
>> > > > > >> >
>> > > > > >> > Gwen
>> > > > > >> >
>> > > > > >> > On Fri, Feb 26, 2016 at 5:11 PM, Ashish Singh <
>> > > asi...@cloudera.com>
>> > > > wrote:
>> > > > > >> > > Parth,
>> > > > > >> > >
>> > > > > >> > > Thanks again for the awesome write up. Following our
>> discussion
>> > > > from the
>> > > > > >> > > JIRA, I think it will be easier to compare various
>> alternatives
>> > > > if they
>> > > > > >> > are
>> > > > > >> > > listed together. I am stating below a few alternatives along
>> > > with
>> > > > a the
>> > > > > >> > > current proposal.
>> > > > > >> > > (Current proposal) Store Delegation Token, DT, on ZK.
>> > > > > >> > >
>> > > > > >> > > 1. Client authenticates with a broker.
>> > > > > >> > > 2. Once a client is authenticated, it will make a broker
>> side
>> > > > call to
>> > > > > >> > > issue a delegation token.
>> > > > > >> > > 3. The broker generates a shared secret based on
>> > > HMAC-SHA256(a
>> > > > > >> > > Password/Secret shared between all brokers, randomly
>> > > generated
>> > > > > >> > tokenId).
>> > > > > >> > > 4. Broker stores this token in its in memory cache.
>> Broker
>> > > > also stores
>> > > > > >> > > the DelegationToken without the hmac in the zookeeper.
>> > > > > >> > > 5. All brokers will have a cache backed by zookeeper so
>> they
>> > > > will all
>> > > > > >> > > get notified whenever a new token is generated and they
>> will
>> > > > update
>> > > > > >> > their
>> > > > > >> > > local cache whenever token state changes.
>> > > > > >> > > 6. Broker returns the token to Client.
>> > > > > >> > >
>> > > > > >> > > Probable issues and fixes
>> > > > > >> > >
>> > > > > >> > > 1. Probable race condition, client tries to authenticate
>> with
>> > > > a broker
>> > > > > >> > > that is yet to be updated with the newly generated DT.
>> This
>> > > can
>> > > > > >> > probably be
>> > > > > >> > > dealt with making dtRequest block until all brokers have
>> > > > updated
>> > > > > >> > their DT
>> > > > > >> > > cache. Zk barrier or similar mechanism can be used.
>> However,
>> > > > all such
>> > > > > >> > > mechanisms will increase complexity.
>> > > > > >> > > 2. Using a static secret key from config file. Will
>> require
>> > > yet
>> > > > > >> > another
>> > > > > >> > > config and uses a static secret key. It is advised to
>> rotate
>> > > > secret
>> > > > > >> > keys
>> > > > > >> > > periodically. This can be avoided with controller
>> generating
>> > > > > >> > secretKey and
>> > > > > >> > > passing to brokers periodically. However, this will
>> require
>> > > > brokers to
>> > > > > >> > > maintain certain counts of secretKeys.
>> > > > > >> > >
>> > > > > >> > > (Alternative 1) Have controller generate delegation token.
>> > > > > >> > >
>> > > > > >> > > 1. Client authenticates with a broker.
>> > > > > >> > > 2. Once a client is authenticated, it will make a broker
>> side
>> > > > call to
>> > > > > >> > > issue a delegation token.
>> > > > > >> > > 3. Broker forwards the request to controller.
>> > > > > >> > > 4. Controller generates a DT and broadcasts to all
>> brokers.
>> > > > > >> > > 5. Broker stores this token in its memory cache.
>> > > > > >> > > 6. Controller responds to broker’s DT req.
>> > > > > >> > > 7. Broker returns the token to Client.
>> > > > > >> > >
>> > > > > >> > > Probable issues and fixes
>> > > > > >> > >
>> > > > > >> > > 1. We will have to add new APIs to support controller
>> pushing
>> > > > tokens
>> > > > > >> > to
>> > > > > >> > > brokers on top of the minimal APIs that are currently
>> > > proposed.
>> > > > > >> > > 2. We will also have to add APIs to support the
>> bootstrapping
>> > > > case,
>> > > > > >> > i.e,
>> > > > > >> > > when a new broker comes up it will have to get all
>> delegation
>> > > > tokens
>> > > > > >> > from
>> > > > > >> > > the controller.
>> > > > > >> > > 3. In catastrophic failures where all brokers go down,
>> the
>> > > > tokens will
>> > > > > >> > > be lost even if servers are restarted as tokens are not
>> > > > persisted
>> > > > > >> > anywhere.
>> > > > > >> > > If this happens, then there are more important things to
>> > > worry
>> > > > about
>> > > > > >> > and
>> > > > > >> > > maybe it is better to re-authenticate.
>> > > > > >> > >
>> > > > > >> > > (Alternative 2) Do not distribute DT to other brokers at
>> all.
>> > > > > >> > >
>> > > > > >> > > 1. Client authenticates with a broker.
>> > > > > >> > > 2. Once a client is authenticated, it will make a broker
>> side
>> > > > call to
>> > > > > >> > > issue a delegation token.
>> > > > > >> > > 3. The broker generates DT of form, [hmac + (owner,
>> renewer,
>> > > > > >> > > maxLifeTime, id, hmac, expirationTime)] and passes back
>> this
>> > > > DT to
>> > > > > >> > client.
>> > > > > >> > > hmac is generated via {HMAC-SHA256(owner, renewer,
>> > > > maxLifeTime, id,
>> > > > > >> > hmac,
>> > > > > >> > > expirationTime) using SecretKey}. Note that all brokers
>> have
>> > > > this
>> > > > > >> > SecretKey.
>> > > > > >> > > 4. Client then goes to any broker and to authenticate
>> sends
>> > > > the DT.
>> > > > > >> > > Broker recalculates hmac using (owner, renewer,
>> maxLifeTime,
>> > > > id, hmac,
>> > > > > >> > > expirationTime) info from DT and its SecretKey. If it
>> matches
>> > > > with
>> > > > > >> > hmac of
>> > > > > >> > > DT, client is authenticated. Yes, it will do other
>> obvious
>> > > > checks of
>> > > > > >> > > timestamp expiry and such.
>> > > > > >> > >
>> > > > > >> > > Note that secret key will be generated by controller and
>> passed
>> > > to
>> > > > > >> > brokers
>> > > > > >> > > periodically.
>> > > > > >> > > Probable issues and fixes
>> > > > > >> > >
>> > > > > >> > > 1. How to delete a DT? Yes, that is a downside here.
>> However,
>> > > > this can
>> > > > > >> > > be handled with brokers maintaining a blacklist of DTs,
>> DTs
>> > > > from this
>> > > > > >> > list
>> > > > > >> > > can be removed after expiry.
>> > > > > >> > > 2. In catastrophic failures where all brokers go down,
>> the
>> > > > tokens will
>> > > > > >> > > be lost even if servers are restarted as tokens are not
>> > > > persisted
>> > > > > >> > anywhere.
>> > > > > >> > > If this happens, then there are more important things to
>> > > worry
>> > > > about
>> > > > > >> > and
>> > > > > >> > > maybe it is better to re-authenticate.
>> > > > > >> > >
>> > > > > >> > >
>> > > > > >> > >
>> > > > > >> > > On Fri, Feb 26, 2016 at 1:58 PM, Parth Brahmbhatt <
>> > > > > >> > > pbrahmbh...@hortonworks.com> wrote:
>> > > > > >> > >
>> > > > > >> > >> Hi,
>> > > > > >> > >>
>> > > > > >> > >> I have filed KIP-48 so we can offer hadoop like delegation
>> > > > tokens in
>> > > > > >> > >> kafka. You can review the design
>> > > > > >> > >>
>> > > > > >> >
>> > > >
>> > >
>> https://cwiki.apache.org/confluence/display/KAFKA/KIP-48+Delegation+token+support+for+Kafka
>> > > > > >> > .
>> > > > > >> > >> This KIP depends on KIP-43 and we have also discussed an
>> > > > alternative to
>> > > > > >> > >> proposed design here<
>> > > > > >> > >>
>> > > > > >> >
>> > > >
>> > >
>> https://issues.apache.org/jira/browse/KAFKA-1696?focusedCommentId=15167800&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15167800
>> > > > > >> > >> >.
>> > > > > >> > >>
>> > > > > >> > >> Thanks
>> > > > > >> > >> Parth
>> > > > > >> > >>
>> > > > > >> > >
>> > > > > >> > >
>> > > > > >> > >
>> > > > > >> > > --
>> > > > > >> > >
>> > > > > >> > > Regards,
>> > > > > >> > > Ashish
>> > > > > >> >
>> > > >
>> > >
>> > >
>> > >
>> > > --
>> > >
>> > > Regards,
>> > > Ashish
>> > >
>>
