* Add ServiceBackend interface
This adds a ServiceBackend interface that is shared between etcd/etcd3
(later) and kubernetes, leading to a massive reduction in code. When
returning the specific records from their backend.
Fixes#273
* middleware/proxy
Use connection pooling for communicating with an upstream, instead of
opening a new socket every time.
This makes the proxy more efficient and allowed for some cleanups.
* Some cleanups
* Some fixes
* more
* Kill pool
* Add nil check
* remove pool
While looking into the proxy middleware it appears that there are
several golint messages:
```
ubuntu@ubuntu:~/coredns$ golint middleware/proxy/
middleware/proxy/lookup.go:66:1: exported method Proxy.Forward should have comment or be unexported
middleware/proxy/proxy.go:24:6: exported type Client should have comment or be unexported
middleware/proxy/proxy.go:107:1: exported function Clients should have comment or be unexported
middleware/proxy/reverseproxy.go:10:6: exported type ReverseProxy should have comment or be unexported
middleware/proxy/reverseproxy.go:16:1: exported method ReverseProxy.ServeDNS should have comment or be unexported
middleware/proxy/upstream.go:42:6: exported type Options should have comment or be unexported
```
This fix addressed the above golint messages.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Move all (almost all) Go files in middleware into their
own packages. This makes for better naming and discoverability.
Lot of changes elsewhere to make this change.
The middleware.State was renamed to request.Request which is better,
but still does not cover all use-cases. It was also moved out middleware
because it is used by `dnsserver` as well.
A pkg/dnsutil packages was added for shared, handy, dns util functions.
All normalize functions are now put in normalize.go
Changes large parts of proxy lookup mechanism.
The duplicate zone checking erroneous added a nameserver for each
zone we are auth. for, creating to many backend hosts. So even when a
host was determined do be Down() we still got an (identical) new one
from the list.
The Down() and failure checking for upstream hosts had data race in the
uh.Fails check - we now use atomic.LoadInt32 for that.
Use and debug the test/server.go test servers implementation in the
TestStubLookup test to prevent going out to the internet.
Also delete the stub cycle test. That test was wrong and did not test
what it needed to be testing. Deleted for now.
* middleware/proxy: add spray keyword
When spray is used, the proxy will, when all backend are down, spray to
each target. When not used, default to the old defaults: max 1 failure
and no spray. These defaults are also used when forwarding queries to
another CoreDNS instance.
Update the README with the new keyword.
* typos
* Make MaxFail = 1 again
* more reversals
This implements stubzones in the same way as SkyDNS. This
also works with multiple configured domains and has tests.
Also add more configuration parameters for TLS and path prefix and
enabling stubzones. Run StubUpdates as a startup command to keep up to
date with the list in etcd.
