Add IGNORE(label) which ignores label at the provider (#183) (#300)

* Add support for the IGNORE(name) directive (#183)

IGNORE is like NO_PURGE but for a spefic record instead of the whole
zone. This is very useful for instance if you have a zone where
only some records are managed externally from dnscontrol (for instance
using kubernetes external dns system).

Adding IGNORE("foo") in the zone will make dnscontrol not trying
to manage the "foo" record (and especially not deleting it).
dnscontrol will error out if the "foo" record is both ignored and
managed in dnscontrol.

This can be seen as a generic Cloudflare's ignored label.

Signed-off-by: Brice Figureau <brice@daysofwonder.com>

* Deprecate CloudFlare ignoredLabels in favor of IGNORE (#183)

Since IGNORE implements a generic `ignoredLabels` system, let
the user know CF `ignoredLabels` are deprecated.

Signed-off-by: Brice Figureau <brice@daysofwonder.com>

integrationTest/integration_test.go

@@ -112,6 +112,7 @@ func runTests(t *testing.T, prv providers.DNSServiceProvider, domainName string,
 				}
 				dom.Records = append(dom.Records, &rc)
 			}
+			dom.IgnoredLabels = tst.IgnoredLabels
 			models.PostProcessRecords(dom.Records)
 			dom2, _ := dom.Copy()
 			// get corrections for first time
@@ -196,8 +197,9 @@ func TestDualProviders(t *testing.T) {
 }
 
 type TestCase struct {
-	Desc    string
-	Records []*rec
+	Desc          string
+	Records       []*rec
+	IgnoredLabels []string
 }
 
 type rec models.RecordConfig
@@ -266,6 +268,13 @@ func tlsa(name string, usage, selector, matchingtype uint8, target string) *rec
 	return r
 }
 
+func ignore(name string) *rec {
+	return &rec{
+		Name: name,
+		Type: "IGNORE",
+	}
+}
+
 func makeRec(name, target, typ string) *rec {
 	return &rec{
 		Name:   name,
@@ -281,9 +290,19 @@ func (r *rec) ttl(t uint32) *rec {
 }
 
 func tc(desc string, recs ...*rec) *TestCase {
+	var records []*rec
+	var ignored []string
+	for _, r := range recs {
+		if r.Type == "IGNORE" {
+			ignored = append(ignored, r.Name)
+		} else {
+			records = append(records, r)
+		}
+	}
 	return &TestCase{
-		Desc:    desc,
-		Records: recs,
+		Desc:          desc,
+		Records:       records,
+		IgnoredLabels: ignored,
 	}
 }
 
@@ -480,5 +499,12 @@ func makeTests(t *testing.T) []*TestCase {
 		)
 	}
 
+	// ignored recrods
+	tests = append(tests,
+		tc("Empty"),
+		tc("Create some records", txt("foo", "simple"), a("foo", "1.2.3.4")),
+		tc("Add a new record - ignoring foo", a("bar", "1.2.3.4"), ignore("foo")),
+	)
+
 	return tests
 }