@Colin we won’t be supporting the subscriber mode currently and it will be added as a future work 2. By disabling the feature the constructor will work as it earlier. If we know the configs don’t have any indirect values or we want the indirect values to remain unresolved we will can just do so by using the enable flag. We won’t be using this in broker as its dynamic and we have added it in future section for now.
On 2019/03/14 16:36:42, "Colin McCabe" <c...@apache.org> wrote: > Hi Tejal,> > > Thanks for the update.> > > One of the critical parts of the ConfigProvider interface is the ability to > monitor changes to a configuration key through ConfigProvider#subscribe and > ConfigProvider#unsubscribe, etc. I don't see how the proposed API supports > this. Can you clarify?> > > Also, it's not clear to me when you would want to enable KIP-421 > functionality and when you would want to disable it. What is the purpose of > making it possible to disable this? Do you have examples of cases where we > would use it and cases where we would not? Would the broker use this > functionality?> > > best,> > Colin> > > > On Mon, Mar 11, 2019, at 10:49, Tejal Adsul wrote:> > > Hi Folks,> > > > > > I have accommodated most of the review comments for > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-421%3A+Support+resolving+externalized+secrets+in+AbstractConfig > > . Reopening the thread for further discussion. Please let me know your > > thoughts on it.> > > > > > Thanks,> > > Tejal> > > > > > On 2019/01/25 19:11:07, "Colin McCabe" <c....@apache.org> wrote: > > > > On Fri, Jan 25, 2019, at 09:12, Andy Coates wrote:> > > > > > > Further, if we're worried about confusion about how to)> > > > > > load the two files, we could have a constructor that does that default> > > > > > > > > > pattern for you.> > > > > > > > > > > > Yeah, I don't really see the need for this two step / two file > > > > approach. I> > > > > > think the config providers should be listed in the main property file, > > > > not> > > > > > some secondary file, and we should avoid backwards compatibility issues > > > > by,> > > > > > as Ewan says, having a new constructor, (deprecating the old), that > > > > allows> > > > > > the functionality to be turned on/off.> > > > > > > > > +1. In the case of the Kafka broker, it really seems like we should put > > > the config providers in the main config file. > > > > > It's more complex to have multiple configuration files, and it doesn't > > > seem to add any value.> > > > > > > > > In the case of other components like Connect, I don't have a strong > > > opinion. We can discuss this on a component-by-component basis. Clearly > > > not all components manage configuration exactly the same way, and that > > > difference might motivate different strategies here.> > > > > > > > > > > > > > > > I suggest we also consider adding a new method to AbstractConfig to > > > > > > allow> > > > > > applications to get the unresolved raw value, e.g. String> > > > > > getRawValue(String key). Given a config entry like "> > > > > > config.providers.vault.password=$> > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/config.providers.vault.password=$>> > > > > > > > > > {file:/path/to/secrets.properties:vault.secret.password}" then > > > > > > getRawValue> > > > > > would always return "$> > > > > > <https://cwiki.apache.org/confluence/display/KAFKA/config.providers.vault.password=$>> > > > > > > > > > {file:/path/to/secrets.properties:vault.secret.password}". I can see > > > > > > > > > > this> > > > > > being useful.> > > > > > > > > I think one of the problems with the interface proposed in KIP-421 is > > > that it doesn't give brokers any way to listen for changes to the > > > configuration. We've done a lot of work to make certain configuration > > > keys dynamic, but we're basically saying if you use external secrets, you > > > can't make use of that at all-- you have to restart the broker to change > > > configuration.> > > > > > > > > Unfortunately, the AbstractConfig interface isn't well suited to > > > listening for config changes. In order to do that, you probably need to > > > use the KIP-297 interface directly. Which means that maybe we should go > > > back to the drawing board here, unfortunately. :(> > > > > > > > > best,> > > > > Colin> > > > > > > > > > > > > > > > With regards to on-change subscription: surely all we'd need is to > > > > provide> > > > > > a way for users to attach a callback for a given key, right? e.g. > > > > `boolean> > > > > > subscribe(key, callback)`, where the return value is true if the key > > > > has a> > > > > > config provider, false if it doesn't. I think this would be worthwhile> > > > > > > > > > including as it stops people having to build their own, doing the > > > > parsing> > > > > > and wiring themselves.> > > > > > > > > > > > Andy> > > > > > > > > > > > On Fri, 25 Jan 2019 at 09:11, Rajini Sivaram <ra...@gmail.com>> > > > > > wrote:> > > > > > > > > > > > > *Regarding brokers, I think if we want to avoid exposing secrets> > > > > > > over DescribeConfigs responses, we'd probably need changes similar to > > > > > those> > > > > > > we needed to make for the Connect REST API. *> > > > > > >> > > > > > > Password configs are not returned in DescribeConfigs response in the> > > > > > > > > > > > broker. The response indicates that the config is sensitive and no > > > > > value is> > > > > > > returned.> > > > > > >> > > > > > >> > > > > > > On Thu, Jan 24, 2019 at 11:38 PM Ewen Cheslack-Postava > > > > > <ew...@confluent.io>> > > > > > > wrote:> > > > > > >> > > > > > > > > It allows _all_ existing clients of the class, e.g. those in > > > > > > > Apache> > > > > > > > Kafka or in applications written by other people that use the > > > > > > class, to> > > > > > > get> > > > > > > > this functionality for free, i.e. without any code changes. (I > > > > > > realize> > > > > > > > this is probably where the 'unexpected effects' comes from).> > > > > > > >> > > > > > > > > Personally, I think we should do our best to make this work > > > > > > > seamlessly> > > > > > > /> > > > > > > > transparently, because we're likely going to have this > > > > > > functionality for> > > > > > > a> > > > > > > > long time.> > > > > > > >> > > > > > > > Connect (and connectors that may also use AbstractConfig for > > > > > > themselves> > > > > > > > since they are supposed to expose a ConfigDef anyway) could > > > > > > definitely be> > > > > > > > an issue. I'd imagine formats like this are rare, but we do know > > > > > > there> > > > > > > are> > > > > > > > some cases where people add new syntax, e.g. the landoop > > > > > > connectors> > > > > > > support> > > > > > > > some sort of inline sql-like transformation. I don't know of any > > > > > > cases> > > > > > > that> > > > > > > > would specifically conflict with the syntax, but there is some > > > > > > risk.> > > > > > > >> > > > > > > > I agree getting it automated would be ideal, and it is probably > > > > > > more> > > > > > > > reasonable to claim any issues would be unlike if unresolvable > > > > > > cases> > > > > > > don't> > > > > > > > result in an exception. On the other hand, I think the vast > > > > > > majority of> > > > > > > the> > > > > > > > benefit would come from making this work for brokers, Connect, and> > > > > > > > > > > > > Streams> > > > > > > > (and in most applications making this work is pretty trivial given > > > > > > the> > > > > > > > answer to question (1) is that it works by passing same config to > > > > > > the> > > > > > > > static method then constructor).> > > > > > > >> > > > > > > > Tying this discussion also back to the question about subscribing > > > > > > for> > > > > > > > updates, apps would commonly need modification to support that, and > > > > > > I> > > > > > > think> > > > > > > > ideally you want to be using some sort of KMS where rotation is > > > > > > done> > > > > > > > automatically and you need to subscribe to updates. Since it's a > > > > > > pretty> > > > > > > > common pattern to only look up configs once instead of always going > > > > > > back> > > > > > > to> > > > > > > > the AbstractConfig, you'd really only be able to get some of the > > > > > > long> > > > > > > term> > > > > > > > intended benefit of this improvement. We should definitely have a > > > > > > follow> > > > > > > up> > > > > > > > to this that deals with the subscriptions, but I think the current > > > > > > scope> > > > > > > is> > > > > > > > still a useful improvement -- Connect got this implemented because> > > > > > > > > > > > > exposure> > > > > > > > of secrets via REST API was such a big problem. Making the changes > > > > > > in> > > > > > > > AbstractConfig is a better long term solution so we can get this > > > > > > working> > > > > > > > with all components.> > > > > > > >> > > > > > > > Regarding brokers, I think if we want to avoid exposing secrets > > > > > > over> > > > > > > > DescribeConfigs responses, we'd probably need changes similar to > > > > > > those we> > > > > > > > needed to make for the Connect REST API. Also agree we'd need to > > > > > > think> > > > > > > > about how to make this work with dynamic configs (which would also > > > > > > be a> > > > > > > > nice thing to extend to, e.g., Connect).> > > > > > > >> > > > > > > > As a practical suggestion, while it doesn't give you the update for > > > > > > free,> > > > > > > > we could consider also deprecating the existing constructor to > > > > > > encourage> > > > > > > > people to update. Further, if we're worried about confusion about > > > > > > how to> > > > > > > > load the two files, we could have a constructor that does that > > > > > > default> > > > > > > > pattern for you.> > > > > > > >> > > > > > > > -Ewen> > > > > > > >> > > > > > > > On Thu, Jan 24, 2019 at 11:36 AM Colin McCabe <cm...@apache.org>> > > > > > > wrote:> > > > > > > >> > > > > > > > > On Thu, Jan 24, 2019, at 11:25, TEJAL ADSUL wrote:> > > > > > > > > >> > > > > > > > > >> > > > > > > > > > On 2019/01/24 17:26:02, Andy Coates <an...@confluent.io> > > > > > > > > wrote:> > > > > > > > > > > I'm wondering why we're rejected changing AbstractConfig to> > > > > > > > > > > > > > > > > > automatically> > > > > > > > > > > resolve the variables?> > > > > > > > > > >> > > > > > > > > > > > 1. Change AbstractConfig to *automatically* resolve > > > > > > > > > > variables of> > > > > > > > the> > > > > > > > > form> > > > > > > > > > > specified in KIP-297. This was rejected because it would > > > > > > > > > change the> > > > > > > > > > > behavior of existing code and might cause unexpected > > > > > > > > > effects.> > > > > > > > > > >> > > > > > > > > > > Doing so seems to me to have two very large benefits:> > > > > > > > > > >> > > > > > > > > > > 1. It allows the config providers to be defined within the > > > > > > > > > same> > > > > > > file> > > > > > > > > as the> > > > > > > > > > > config that uses the providers, e.g.> > > > > > > > > > >> > > > > > > > > > > config.providers=file,vault> > > > > > > > > > > <> > > > > > > > >> > > > > > > >> > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/config.providers=file,vault> > > > > > > > > > > > > > >> > > > > > > > > > > config.providers.file.> > > > > > > > > > > <> > > > > > > > >> > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/config.providers.file> > > > > > > > > > > > > .>> > > > > > > > > > > class=org.apache.kafka.connect.configs.FileConfigProvider> > > > > > > > > > > <> > > > > > > > >> > > > > > > >> > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/org.apache.kafka.connect.configs.FileConfigProvider> > > > > > > > > > > > > > >> > > > > > > > > > > config.providers.file.param.path=> > > > > > > > > > > <> > > > > > > > >> > > > > > > >> > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/config.providers.file.other.prop=another> > > > > > > > > > > > > > >> > > > > > > > > > > /mnt/secrets/passwords> > > > > > > > > > >> > > > > > > > > > > foo.baz=/usr/temp/> > > > > > > > > > > <> > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/foo.baz=/usr/temp/>> > > > > > > > > > > > > > > > > foo.bar=$ <> > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/foo.bar=$> > > > > > > > > >> > > > > > > > > > > {file:/path/to/variables.properties:foo.bar}> > > > > > > > > > >> > > > > > > > > > > Is this possible with what's currently being proposed? i.e > > > > > > > > > could> > > > > > > you> > > > > > > > > load> > > > > > > > > > > the file and pass the map first to `loadConfigProviders` and > > > > > > > > > then> > > > > > > > > again to> > > > > > > > > > > the constructor?> > > > > > > > > > >> > > > > > > > > > > 2. It allows _all_ existing clients of the class, e.g. those > > > > > > > > > in> > > > > > > > Apache> > > > > > > > > > > Kafka or in applications written by other people that use > > > > > > > > > the> > > > > > > class,> > > > > > > > > to get> > > > > > > > > > > this functionality for free, i.e. without any code changes. > > > > > > > > > (I> > > > > > > > realize> > > > > > > > > > > this is probably where the 'unexpected effects' comes from).> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > I'm assuming the unexpected side effects come about if an > > > > > > > > > existing> > > > > > > > > > > properties file already contains compatible config.providers> > > > > > > > > > > > > > > > > > > > <> > > > > > > > >> > > > > > > >> > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/config.providers=file,vault> > > > > > > > > > > > > > >> > > > > > > > > > > entries _and_ has other properties in the form ${xx:yy} or> > > > > > > > > > > > > > > > > > ${xx:yy:zz}.> > > > > > > > > > > While possible, these seems fairly unlikely unless for > > > > > > > > > random> > > > > > > client> > > > > > > > > > > property files. So I'm assuming there's a specific instance > > > > > > > > > where> > > > > > > we> > > > > > > > > think> > > > > > > > > > > this is likely? Something to do with Connect config maybe?> > > > > > > > > > >> > > > > > > > > > > Personally, I think we should do our best to make this work> > > > > > > > > > > > > > > > > seamlessly> > > > > > > > > /> > > > > > > > > > > transparently, because we're likely going to have this> > > > > > > functionality> > > > > > > > > for a> > > > > > > > > > > long time.> > > > > > > > > > >> > > > > > > > > > > Andy> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > > On Tue, 22 Jan 2019 at 17:38, te...@confluent.io <> > > > > > > te...@confluent.io> > > > > > > > >> > > > > > > > > wrote:> > > > > > > > > > >> > > > > > > > > > > > Hi all,> > > > > > > > > > > >> > > > > > > > > > > > We would like to start vote on KIP-421 to to enhance the> > > > > > > > > AbstractConfig> > > > > > > > > > > > base class to support replacing variables in configurations > > > > > > > > > > just> > > > > > > > > prior to> > > > > > > > > > > > parsing and validation.> > > > > > > > > > > >> > > > > > > > > > > > Link for the KIP:> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-421%3A+Support+resolving+externalized+secrets+in+AbstractConfig> > > > > > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > > Thanks,> > > > > > > > > > > > Tejal> > > > > > > > > > > >> > > > > > > > >> > > > > > > > > Hi,> > > > > > > > >> > > > > > > > > I think Andy and Rajini bring up a good point. If this change > > > > > > > is> > > > > > > limited> > > > > > > > > to just Connect, then it's not completely clear why it needs to > > > > > > > be in> > > > > > > > > AbstractConfig. On the other hand, if it applies to brokers and> > > > > > > > > > > > > > clients> > > > > > > > > (and other things), then we should figure out how that > > > > > > > integration will> > > > > > > > > look.> > > > > > > > >> > > > > > > > > > > Hi Andy,> > > > > > > > > >> > > > > > > > > > So wanted to make sure that we come up with a simple approach > > > > > > > > with no> > > > > > > > > > side effects or additional changes to any components. The > > > > > > > > rejected> > > > > > > > > > approach would require a change in Connect's behavior and we > > > > > > > > dint> > > > > > > want> > > > > > > > > > to make that for this approach.> > > > > > > > >> > > > > > > > > It seems like it should be possible to keep Connect's behavior > > > > > > > the same> > > > > > > > as> > > > > > > > > it is now, but add automatic external configuration lookup to the > > > > > > > Kafka> > > > > > > > > broker. In order to do this, we could have an additional > > > > > > > parameter> > > > > > > that> > > > > > > > > was set by the broker but not by Connect.> > > > > > > > >> > > > > > > > > One candidate is we could have a Java parameter which describes > > > > > > > which> > > > > > > > > config key to look at to find the config providers. Then the > > > > > > > broker> > > > > > > > could> > > > > > > > > set this, but connect could leave it unset. Then people using > > > > > > > the> > > > > > > broker> > > > > > > > > could describe their config providers in the configuration file > > > > > > > itself,> > > > > > > > and> > > [message truncated...]
