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weaveworks / weave

Simple, resilient multi-host containers networking and more.
https://www.weave.works
Apache License 2.0
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Maintain a local cache of forwarded forward DNS lookups #2014

Open pidster opened 8 years ago

pidster commented 8 years ago

A queryable cache of forward DNS lookups that have been forwarded by Weave DNS will enable a probe to identify well-known external services used by an application monitored by Scope.

tomwilkie commented 8 years ago

Scope already does reverse lookups on ip addresses and know this information.

On Wednesday, 2 March 2016, Pid notifications@github.com wrote:

A queryable cache of forward DNS lookups that have been forwarded by Weave DNS will enable a probe to identify well-known external services used by an application monitored by Scope.

— Reply to this email directly or view it on GitHub https://github.com/weaveworks/weave/issues/2014.

rade commented 8 years ago

I believe the issue is that for the services in question there is no reverse lookup information available.

pidster commented 8 years ago

@tomwilkie can Scope identify whether an application component is using SQS or SES, from the reverse lookup of an IP address alone?

@errordeveloper and I couldn't see how to do this as the results returned by the reverse lookup did not match the record used for the forward lookup.

awh commented 8 years ago

I'm not sure where the reverse lookups are currently performed, but I would suggest in this case you would want them to be done by each probe against its co-located weaveDNS instance to avoid having to distribute the cache.

tomwilkie commented 8 years ago

The reverse lookups are done by each probe against the system resolver:

https://github.com/weaveworks/scope/blob/master/probe/endpoint/resolver.go