This still needs cleanup, but this is a first pass the cleans some
cruft and documents our style (in middleware.md) and makes all the
docs match that style.

Add the ability to add a class of responses to be logged; success,
denial or error. The default is to log everything (all).

Fixes #258

Make tests compile; failed to catch this due to use of tags for this
part of the (test) code.

Some document improvements and add a few more tests.

Add support for wildcard records, while taking care of wildcard-cnames
and DNSSEC. Add enough tests to check all the corner cases.

Rename: positive -> success
negative -> denial

There is a third (unused category) which is error. Start using these
new in the caching middleware and later in the logging middleware.

* 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

Make DefaultPort just be 53. And use the value of Port to make the zone
stanzas complete (instead of defaulting to 53 always). This allows you
to override the port with dns.port.

This is purely travis (and maybe local testing). Does not warrent (IMHO)
a contrib/ directory. Hide it in a .travis directory.

Make the methods that handle Metrics all use pointer receivers to fix
sync.Once not being initialized.

Finish the setup_test to test for failures. And make the check for the
address more strict and return an error when it does not have a port
number.

Add a toplevel test that starts a CoreDNS server with metrics enabled
so we catch these errors in the future.

This fix fixes a typo in middle/cache/README.md:
`1 hours` => `1 hour`
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

Make it return an error when you use `transfer from` when you're
not a secondary.

Add tests as well.

Fixes #310

Fix the unknown flags handling when receiving such message. We should
zero out all of the Z bits in the OPT record before returning.

Current behavior:

    dig +norec +noad +ednsflags=0x80 soa miek.nl @deb.atoom.net
    ...
    ; EDNS: version: 0, flags:; MBZ: 0080 , udp: 4096

New:

    dig +norec +noad +ednsflags=0x80 soa miek.nl @localhost -p 2053
    ...
    ; EDNS: version: 0, flags:; udp: 4096

Take care no to overwrite the Do bit.

We still accept *all* EDNS option; I do not consider that a bug in
itself.

Fixes #306

* Add a setup test for middleware/file

This fix adds a setup test for middleware/file so that there is
a basic coverage for the Corefile processing of middleware/file.

This fix is related to 308 (Will look into it).
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* middleware/file: use helper function for test

Fixup setup_test.go and use the test.TempFile function to make things
somewhat shorter.

Use clean up the use of testing.T in TempFile - it is not used.

Make the cache memory bounded, by using a LRU cache. Also split the
cache in a positive and negative one - each with its own controls.

Extend the cache stanza to allow for this:

    cache {
       positive limit [ttl]
       negative limit [ttl]
    }

is now possible. This also add a cache_test.go in the toplevel test/
directory that exercises the caching path.

Fixes #260

This fix updates .travis.yml and Makefile for several places:
- Remove unneeded `docker pull gcr.io/google_containers/hyperkube-amd64:v1.2.4` (only v1.3.7 was used)
- Use docker to deploy etcd (insteadof downloading etcd binary).
- Merge `make testk8s` and `make testk8s-setup` (no need to have multiple targets for a couple of tests)
- Set version of etcd and kubernetes in .travis.yml (so that it is easy to update new version in the future)
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

Add tests for parsing etcd Corefile stanza. Discover a bug in the code,
fix that as well.

This fix moves the content of `.coverage.sh` to the Makefile
and creates a target of `make coverage`. This cleans up as
there is really no need to have a redundant script for
simple coverage test.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

This fix cleans up `.travis.yml` and use `go_import_path`
to replace the customerized script for go import path
(in case the build is from a forked repo).
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

Avoid clashing with other server types.

This clashes to Caddy, which also has its own quiet flag. Move stuff
around a bit, also to prevent cyclic imports.

* Doc: add package docs

Add short package level docs to make godoc looks nicer.
Add some badges to the README.

* correct url

Fix the crash and add `setup_test.go` to catch this in the future.

Fixes #292

Fixes #293

* Added TLS to k8s client

Added options for TLS kubernetes client connection.

* Fix k8s TLS config option parsing

Brings config option parsing for kubernetes TLS in line with recent changes.

* Put TLS config on one line

Put kubernetes tls config on one line to match style established in etcd tls config.

* Add tls option to README

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>

Lint k8s middleware

Refactoring of k8s helpers

* Fix linter errors

* More linting fixes

* More docs and making members private that dont need to be public

* Fix linter errors

* More linting fixes

* More docs and making members private that dont need to be public

* More lint fixes

This leaves:

~~~
middleware/kubernetes/nametemplate/nametemplate.go:64:6: exported type NameTemplate should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:71:1: exported method NameTemplate.SetTemplate should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:108:1: exported method NameTemplate.GetZoneFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:116:1: exported method NameTemplate.GetNamespaceFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:120:1: exported method NameTemplate.GetServiceFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:124:1: exported method NameTemplate.GetTypeFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:135:1: exported method NameTemplate.GetSymbolFromSegmentArray should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:167:1: exported method NameTemplate.IsValid should have comment or be unexported
middleware/kubernetes/nametemplate/nametemplate.go:182:6: exported type NameValues should have comment or be unexported
middleware/kubernetes/util/util.go:1:1: package comment should be of the form "Package util ..."
middleware/kubernetes/util/util.go:27:2: exported const WildcardStar should have comment (or a comment on this block) or be unexported
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
~~~

I plan on reworking the proxy anyway, so I'll leave that be.

Revert k8s changes