This change adds a new `dns_config.recursor_strategy` option which
controls how Consul queries DNS resolvers listed in the `recursors`
config option. The supported options are `sequential` (default), and
`random`.
Closes#8807
Co-authored-by: Blake Covarrubias <blake@covarrubi.as>
Co-authored-by: Priyanka Sengupta <psengupta@flatiron.com>
A previous commit started using QueryRefuced, but that is not correct. QueryRefuced refers to
the OpCode, not the query type.
Instead use errNoAnswer because we have no records for that query type.
Now that trimDNSResponse is handled by the caller we don't need to pass this value
around. We can remove it from both the serviceLookup struct, and two functions.
The dispatch function was called from a single place and did nothing but add a default value.
Removing it makes code easier to trace by removing an unnecessary hop.
* return an invalid record when asked for an addr dns with type other then A and AAAA
* add changelog
* fix ANY use case and add a test for it
* update changelog type
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
* return empty response if the question record type do not match for addr
* set comment in the right place
* return A\AAAA record in extra section if record type is not A\AAAA for addr
* Fix failing test
* remove commented code
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
* use require for test validation
* use variable to init struct
* fix failing test
* Update agent/dns.go
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
* Update .changelog/10401.txt
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
* Update agent/dns.go
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
* Update agent/dns.go
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
* Update agent/dns.go
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
* fix compilation error
Co-authored-by: Daniel Nephin <dnephin@hashicorp.com>
Send empty array [] instead of [""] in DNS requests when TagFilter is not set
Do not change case sensitivity of services anymore in `getServiceNodes()` since
cache keys are now case insensitive
This new package provides a client agent implementation of an interface
for fetching the health of services.
This approach has a number of benefits:
1. It provides a much more explicit interface. Instead of everything
dependency on `RPC()` and `Cache.Get()` for many unrelated things
they can depend on a type that are named according to the behaviour
it provides.
2. It gives us a single place to vary the behaviour and migrate to
a new form of RPC (gRPC). The current implementation has two options
(cache, or direct RPC), and in the future we will have more.
It is also a great opporunity to start adding `context.Context` args
to these operations, which in the future will allow us to cancel
the operations.
3. As a concequence of the first, in the Server agent where we make
these calls we can replace the current in-memory RPC calls with
a thin adapter for the real method. This removes the `net/rpc`
machinery from the call in places where it is not needed.
This new package is quite small right now, but I think we can expect it
to grow to a more reasonable size as other RPC calls are replaced.
This change also happens to replace two very similar implementations with
a single implementation.
Previsouly it was done in Agent.Start, which is much later then it needs to be.
The new 'dns' package was required, because otherwise there would be an
import cycle. In the future we should move more of the dns server into
the dns package.
Previously, we were only returning a single ListenerPort for a single
service. However, we actually allow a single service to be serviced over
multiple ports, as well as allow users to define what hostnames they
expect their services to be contacted over. When no hosts are defined,
we return the default ingress domain for any configured DNS domain.
To show this in the UI, we modify the gateway-services-nodes API to
return a GatewayConfig.Addresses field, which is a list of addresses
over which the specific service can be contacted.
This will allow to increase cache value when DC is not valid (aka
return SOA to avoid too many consecutive requests) and will
distinguish DC being temporarily not available from DC not existing.
Implements https://github.com/hashicorp/consul/issues/8102
Blocking queries issues will still be uncancellable (that cannot be helped until we get rid of net/rpc). However this makes it so that if calling getWithIndex (like during a cache Notify go routine) we can cancell the outer routine. Previously it would keep issuing more blocking queries until the result state actually changed.
* Implements a simple, tcp ingress gateway workflow
This adds a new type of gateway for allowing Ingress traffic into Connect from external services.
Co-authored-by: Chris Piraino <cpiraino@hashicorp.com>
* Use consts for well known tagged adress keys
* Add ipv4 and ipv6 tagged addresses for node lan and wan
* Add ipv4 and ipv6 tagged addresses for service lan and wan
* Use IPv4 and IPv6 address in DNS
* Add updated github.com/miekg/dns to go modules
* Add updated github.com/miekg/dns to vendor
* Fix github.com/miekg/dns api breakage
* Decrease size when trimming UDP packets
Need more room for the header(?), if we don't decrease the size we get an
"overflow unpacking uint32" from the dns library
* Fix dns truncate tests with api changes
* Make windows build working again. Upgrade x/sys and x/crypto and vendor
This upgrade is needed because of API breakage in x/sys introduced
by the minimal x/sys dependency of miekg/dns
This API breakage has been fixed in commit
855e68c859
Refactor dns to have same behavior between A and SRV.
Current implementation returns the node name instead of the service
address.
With this fix when querying for SRV record service address is return in
the SRV record.
And when performing a simple dns lookup it returns a CNAME to the
service address.
This allows addresses to be tagged at the service level similar to what we allow for nodes already. The address translation that can be enabled with the `translate_wan_addrs` config was updated to take these new addresses into account as well.
The DNS config parameters `recursors` and `dns_config.*` are now hot
reloaded on SIGHUP or `consul reload` and do not need an agent restart
to be modified.
Config is stored in an atomic.Value and loaded at the beginning of each
request. Reloading only affects requests that start _after_ the
reload. Ongoing requests are not affected. To match the current
behavior the recursor handler is loaded and unloaded as needed on config
reload.
* Fix race condition in DNS when using cache
The healty node filtering was modifying the result from the cache, which
caused a crash when multiple queries were made to the same service
simultaneously.
We now copy the node slice before filtering to ensure we do not modify
the data stored in the cache.
* Fix wording in dns cache config doc
s/dns_max_age/cache_max_age/
Adds two new configuration parameters "dns_config.use_cache" and
"dns_config.cache_max_age" controlling how DNS requests use the agent
cache when querying servers.
