* Add regression test for broken DNS truncation

With the latest changes to the implementation, request.Scrub() returns
invalid response messages which are larger than the advertised buffer
size. This commit adds a failing test for that.

* Add benchmark for response truncation

* request: re-adjust size for edns0 RR

Cherry-picked the test and benchmark commits from #1962 and make the
failing test not fail, by adding minimal fix in request.go.

This makes size 12 bytes smaller if we need to add back the OPT RR in
the message.

Closes: #1962
Signed-off-by: Miek Gieben <miek@miek.nl>

* Scrub: correctly check for EDNS0, not only Do

Make Scrub check for EDNS0, not only if the Do bit is set.
Signed-off-by: Miek Gieben <miek@miek.nl>

This downloads gometalinter (which is now breaking in the CI tests).
Also the goimports target is run with ||true, so nothing will break
if this flags anything (done because of gofmt changes in between
release).

Probably I will setup something to use github's linter API:
https://github.com/markstory/lint-reviewSigned-off-by: Miek Gieben <miek@miek.nl>

Signed-off-by: Miek Gieben <miek@miek.nl>

* Document current limitations of loop

* Update README.md

The Onstartup loop wouldn't call break after the first success, thereby
sending the query multiple times and halting the process.

Some small other optimizations as well.
Signed-off-by: Miek Gieben <miek@miek.nl>

Signed-off-by: Lorenzo Fontana <lo@linux.com>

Generate the sha256 sum of each asset. These should all be automatically
be uploaded in the github-push target.
Signed-off-by: Miek Gieben <miek@miek.nl>

* New plugin: loop

Add a plugin that detects loops. It does this by sending an unique query
to our selves. If we see the query more than twice we stop the process.
If there isn't a loop, the plugin disables it self and becomes a noop
plugin.
Signed-off-by: Miek Gieben <miek@miek.nl>

* bliep
Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin/log: add log.Fatal[f]

Add log.Fatal(f) to mimic more of the log package. The first and only
use is in the (new) loop plugin.
Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin/erratic: add axfr support

Add support for axfr. This to fix and test long standing axfr issues
that are hard to test if we don't support it directly in coredns.

The most intriguing feature is withholding the last SOA from a response
so the client needs to wait; drop (no reply) and delay is also
supported. All TTLs are set to zero.

Add simple tests that checks if first record is a SOA.
Signed-off-by: Miek Gieben <miek@miek.nl>

* more test coverage
Signed-off-by: Miek Gieben <miek@miek.nl>

* Clean up tests logging

This cleans up the travis logs so you can see the failures better.

Older tests in tests/ would call log.SetOutput(ioutil.Discard) in
a haphazard way. This add log.Discard and put an `init` function in each
package's dir (no way to do this globally). The cleanup in tests/ is
clear.

All plugins also got this init function to have some uniformity and kill
any (future) logging there in the tests as well.

There is a one-off in pkg/healthcheck because that does log.
Signed-off-by: Miek Gieben <miek@miek.nl>

* bring back original log_test.go
Signed-off-by: Miek Gieben <miek@miek.nl>

* suppress logging here as well
Signed-off-by: Miek Gieben <miek@miek.nl>

Logs the amount of entries we parsed after every parse, but only when
debug is loaded.
Signed-off-by: Miek Gieben <miek@miek.nl>

Fixes #1960

Log and returns an error when the name rewrite creates a name that is
illegal. Add test in name_test.go to see if an error is returned.

Possible followup could be the only check this if a name-rewrite is
done.

Fixes: #1638
Signed-off-by: Miek Gieben <miek@miek.nl>

Automatically submitted.

Releasing 1.2.0 uncovered some rough edges that need to be documented.
Also fix github-push target and docker login.
Signed-off-by: Miek Gieben <miek@miek.nl>

Automatically submitted.

* release: automate the release

This PR aims to various pieces into place so we can automate the coredns
release. It needs the script from coredns/release to be installed. Dreck
is to be setup as described in coredns/release/README.md

The release-coredns script can be tested and allows for other branches
than master to be test.

This PR also features some cleanup in the Makefile.release so we don't
call the godep target for each linux release - this speeds it up for
some bit.

Manually running ./release-coredns -t auto-release builds the artifects
for this release, but (of course) doesn't upload anything yet.

Add /release to the OWNERS and allow command to be executed (this still
needs to be tested).
Signed-off-by: Miek Gieben <miek@miek.nl>

* that makefile target doesnt exist anymore
Signed-off-by: Miek Gieben <miek@miek.nl>

* test release for now
Signed-off-by: Miek Gieben <miek@miek.nl>

* Slightly better output
Signed-off-by: Miek Gieben <miek@miek.nl>

* remove again
Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin/forward: add HealthChecker interface

Make the HealthChecker interface and morph the current DNS health
checker into that interface.

Remove all whole bunch of method on Forward that didn't make sense.

This is done in preparation of adding a DoH client to forward - which
requires a completely different healthcheck implementation (and more,
but lets start here)
Signed-off-by: Miek Gieben <miek@miek.nl>

* Use protocol
Signed-off-by: Miek Gieben <miek@miek.nl>

* Dial doesnt need to be method an Forward either
Signed-off-by: Miek Gieben <miek@miek.nl>

* Address comments

Address various comments on the PR.
Signed-off-by: Miek Gieben <miek@miek.nl>

Prevent future; "remove trailing whitespace" PR, but adding a simple
presubmit that checks for this.

This presubmit flagged quite some offenders, remove all trailing
whitespace from. Apart from that there aren't any other changes.
Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin/metadata: finish documentation

Finish the README.md, add corner case in the IsLabel test and reword
some code comments slightly.

Generate the man-pages and add man/coredns-metadata.7 as well.
Signed-off-by: Miek Gieben <miek@miek.nl>

* Fix test
Signed-off-by: Miek Gieben <miek@miek.nl>

- compliance with metadata contract. If metadata value is empty, ignore rewrite - like if metadata does not exist. (#1953)

* - add support of metadata values for edns0 local variables

* - comments from review.

* - simplify label check. Add UT

* - enhance check for Labels, add UT
- remove IsMetadataSet

* - edns0 variable - if variable is not found just ignore the rewrite.

Fix documentation and remove the unused From method.
Signed-off-by: Miek Gieben <miek@miek.nl>

Fix documentation and touch up plugin/forward/README.md
Signed-off-by: Miek Gieben <miek@miek.nl>

* DoH: put in pkg/doh

Factor out the DoH stuff into its own package, add function to request
a DoH response. This can be used by forward (and maybe proxy) to
implement DoH client support.
Signed-off-by: Miek Gieben <miek@miek.nl>

* lint
Signed-off-by: Miek Gieben <miek@miek.nl>

* ... and make it compile
Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin/forward: add prefer_udp option

* updated according to code review

 - fixed linter warning
 - removed metric parameter in Proxy.Connect()

Automatically submitted.

* Doc updates

Make the name section fit on one line.
Signed-off-by: Miek Gieben <miek@miek.nl>

* Regen docs
Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin/metadata: adjust doc to latest code.
Signed-off-by: Miek Gieben <miek@miek.nl>

Automatically submitted.

Allow plugins to dump messages in text pcap to the log. The forward
plugin does this when a reply does not much the query.

If the debug plugin isn't loaded Hexdump and Hexdumpf are noop.
Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin/cache: add extra test for FORMERR

Add extra test that test for not caching a formerr.
Signed-off-by: Miek Gieben <miek@miek.nl>

* govet
Signed-off-by: Miek Gieben <miek@miek.nl>

Exporting Zone.File to avoid getters and setters

Updating getter and setter for Zone.File to be less racy

Renaming GetFile to File in zone plugin

* request: add LocalIP

Fix TODO that was added: Add LocalIP and test the Clear() method.
Signed-off-by: Miek Gieben <miek@miek.nl>

* Move to Errorf

PR feedback and move to Errorf instead Fatalf.
Signed-off-by: Miek Gieben <miek@miek.nl>

This was done anyway, but only deep in the functions, just do this
everywhere; allows for shorter code and request.Request allows for
caching as well.

Cleanups, make it more Go like.
* remove unneeded switches
* remove testdir (why was this there??)
* simplify the logic
* remove unneeded variables
* put short functions on a single line
* fix documentation.
* spin off wire funcs in wire.go, make them functions.
Signed-off-by: Miek Gieben <miek@miek.nl>

k8s' client-go has been updated to v8.0.0 (1.11). This fix
updates client-go dependency so that it is in sync.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>