This fix adjusted codecov config (codecov.yml) so that
commit status is success as long as coverage > 40%.

This fix fixes #752.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

Fix transferring the zone from a master and the matching of notifies
to source and dst IP addresses.

Add `upstream` keyword as well, because it is needed for the same
reasons as in the *file* middlware.
Add some dire warning about upstream in the readme of both middlewares.

Out of band testing, hidden by net build tag was added. Integration
testing still needs to be setup.

We would silently ignore anything that we couldn't parse on the command
line, this change make this an error.

Fixes #743

Cant' transfer zone from masters without populating `f`.
This error prevents secondary zones recognized as "true" secondary, so secondary setting never worked.

In grafana we miss the context of where this is called, make the name
more descriptive.

Also test the GH webhook.

* update dockerfile to allow use of https_google

to use TLS in a docker container (based on Alpine linux) you need to also include the CA certificate files

* cleaned up version of Dockerfile that supports https_google

* cleanup: go vet and golint run

Various cleanups trickered by go vet and golint.

* Fix tests and lowercase all errors

Lowercase all errors, some tests in kubernetes use errors from
kubernetes which do start with a capital letter.

* federation initial commit

* UTs/bugfixes

* federation bits

* polish, cover UT gaps

* add TODO

* go fmt & todo note

* remove unrelated change

* pr changes

* start node watcher

* get real node name

* remove unused case

* middleware/debug: add

Add a debug "middleware" that disables the recover() and just lets
CoreDNS crash; very useful for testing.

Fixes ##563

* fix test

* Feedback: check the value of Debug

Don't load a zone with a SOA record, barf with 'no SOA record' error.

* cache: add sharded cache implementation

Add Cache impl and a few tests. This cache is 256-way sharded, mainly
so each shard has it's own lock. The main cache structure is a readonly
jump plane into the right shard.

This should remove the single lock contention on the main lock and
provide more concurrent throughput - Obviously this hasn't been tested
or measured.

The key into the cache was made a uint32 (hash.fnv) and the hashing op
is not using strings.ToLower anymore remove any GC in that code path.

* here too

* Minimum shard size

* typos

* blurp

* small cleanups no defer

* typo

* Add freq based on Johns idea

* cherry-pick conflict resolv

* typo

* update from early code review from john

* add prefetch to the cache

* mw/cache: add prefetch

* remove println

* remove comment

* Fix tests

* Test prefetch in setup

* Add start of cache

* try add diff cache options

* Add hacky testcase

* not needed

* allow the use of a percentage for prefetch

If the TTL falls below xx% do a prefetch, if the record was popular.
Some other fixes and correctly prefetch only popular records.

A somewhat longer living PR to group documentation updates

It's not used, remove it.

* core: -log bolean flag to enable logging

Change to -log flag to a boolean that defaults false and when true
logs to stdout.

* And bool here

* add hosts middleware

* forgot pointer receiver

* add appropriately modified hostsfile tests from golang repo

* remove test artifacts, separate hostsfile parsing from caching and opening, remove unused metrics references, move middleware up the chain

* refactored the logic for creating records and filtering ip address versions. also got PTR lookups working

* Add README.md. Modify config to be more concise. Add zones list to config. Filter PTR responses based on zones list.

* add Fallthrough and return correct dns response code otherwise

* Simplified Hostsfile to only store hosts in the zones we care about, and by ip version. Added handler tests and improved other tests.

* oops, goimports loaded a package from a different repo

* middleware/file: don't reload zone when SOA isn't changed

Give Parse an extra argument which is the SOA's serial, if > 0 we check
against the just parsed SOA and then just return.

Most notable use is in reload.go which is both used in the file and auto
middleware.

Fixes #415

* PR comments

Singleinflight interferes with the health checking of upstream. If an
upstream would fail, singleinflight would mirror that error to to other
proxy *iff* multple identical queries would be inflight. This would lead
to marking *all* upstreams as bad, essentially collapsing multiple
upstreams into a SPOF. Clearly not what we want.

Singleinflight does have some nice properties, but I've opted to rip it
out entirely. Caching should almost (but not quite) as good.

Added a test case in test that uses 3 CoreDNS instances to reflect the
setup from #715.

Found another bug as well, where (when the policy would be nil), we
would always Spray even though we've found a healthy host.

Fixed in upstream, update miekg/dns to latest

Fixes #598

We already lowercase before comparing.

Fixes #447

* Removed caddy

* new stuff

* Now need to go get caddy

* Duh

* middleware/proxy: silence gprc errors

Add discard logger

* Silence glog crap

* Revert "Silence glog crap"

This reverts commit a15dafbca62b4e91d4c41543b4c06b8c39a5e500.

* middleware/file: add DNSSEC support

Add tests for DNSSEC and check if everything is working.

* add signatures

* tweak

* Add DNSSEC signing tests for DNAME

* Just sign it all

This commit updates CONTRIBUTING.md to add a section for vendor management.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

When CoreDNS starts up and can't get a zone transfer going the Apex is
empty. This `nil` is then transformed into wireformat, which fails with
a nil pointer dereference in Go DNS.

In this case we should just return SERVFAIL, because we don't have any
info (yet). Note the lookup code returned NXDOMAIN, which is correct
from a lookup standpoint, but also invalidates every name in the future
loaded zone.

Anyway, look for an apex before doing the lookup and return SERVFAIL if
nothing is found.

Fixes #679

Limit the options in both errors and log middleware, just output to
stdout and let someone else (journald,docker) care about where to route
the logs. This removes syslog and logging to a file.

Fixes #573 #602