k8s middleware cleanup, testcases, basic SRV (#181)

* Removing unnecessary gitignore pattern

* Updating Makefile to run unittests for subpackages

* Adding Corefile validation to ignore overlapping zones

* Fixing SRV query handling

* Updating README.md now that SRV works

* Fixing debug message, adding code comment

* Clarifying implementation of zone normalization

* "Overlapping zones" is ill-defined. Reimplemented zone overlap/subzone
  checking to contain these functions in k8s middleware and provide
  better code comments explaining the normalization.

* Separate build verbosity from test verbosity

* Cleaning up comments to match repo code style

* Merging warning messages into single message
* Moving function docs to before function declaration

* Adding test cases for k8sclient connector

* Tests cover connector create and setting base url
* Fixed bugs in connector create and setting base url functions

* Updaing README to group and order development work

* Priority focused on achieving functional parity with SkyDNS.

* Adding work items to README and cleaning up formatting

* More README format cleaning

* List formating

* Refactoring k8s API call to allow dependency injection

* Add test cases for data parsing from k8s into dataobject structures

* URL is dependency-injected to allow replacement with a mock http
  server during test execution

* Adding more data validation for JSON parsing tests

* Adding test case for GetResourceList()

* Adding notes about SkyDNS embedded IP and port record names

* Marked test case implemented.

* Fixing formatting for example command.

* Fixing formatting

* Adding notes about Docker image building.

* Adding SkyDNS work item

* Updating TODO list

* Adding name template to Corefile to specify how k8s record names are assembled

* Adding template support for multi-segment zones

* Updating example CoreFile for k8s with template comment

* Misc whitespace cleanup

* Adding SkyDNS naming notes

* Adding namespace filtering to CoreFile config

* Updating example k8sCoreFile to specify namespaces

* Removing unused codepath

* Adding check for valid namespace

* More README TODO restructuring to focus effort

* Adding template validation while parsing CoreFile

* Record name template is considered invalid if it contains a symbol of the form ${bar} where the symbol
  "${bar}" is not an accepted template symbol.

* Refactoring generation of answer records

* Parse typeName out of query string
* Refactor answer record creation as operation over list of ServiceItems

* Moving k8s API caching into SkyDNS equivalency segment

* Adding function to assemble record names from template

* Warning: This commit may be broken. Syncing to get laptop code over to dev machine.

* More todo notes

* Adding comment describing sample test data.

* Update k8sCorefile

* Adding comment

* Adding filtering support for kubernetes "type"

* Required refactoring to support reuse of the StringInSlice function.

* Cleaning up formatting

* Adding note about SkyDNS supporting word "any".

* baseUrl -> baseURL

* Also removed debug statement from core/setup/kubernetes.go

* Fixing test breaking from Url -> URL naming changes

* Changing record name template language ${...} -> {...}

* Fix formatting with go fmt

* Updating all k8sclient data getters to return error value

* Adding error message to k8sclient data accessors

* Cleaning up setup for kubernetes

* Removed verbose nils in initial k8s middleware instance
* Set reasonable defaults if CoreFile has no parameters in the
kubernetes block. (k8s endpoint, and name template)

* Formatting cleanup -- go fmt

middleware/kubernetes/lookup.go

@@ -17,7 +17,7 @@ func (k Kubernetes) records(state middleware.State, exact bool) ([]msg.Service,
 	if err != nil {
 		return nil, err
 	}
-    // TODO: Do we want to support the SkyDNS (hacky) Group feature?
+	// TODO: Do we want to support the SkyDNS (hacky) Group feature?
 	services = msg.Group(services)
 	return services, nil
 }
@@ -141,7 +141,7 @@ func (k Kubernetes) AAAA(zone string, state middleware.State, previousRecords []
 	return records, nil
 }
 
-// SRV returns SRV records from etcd.
+// SRV returns SRV records from kubernetes.
 // If the Target is not a name but an IP address, a name is created on the fly.
 func (k Kubernetes) SRV(zone string, state middleware.State) (records []dns.RR, extra []dns.RR, err error) {
 	services, err := k.records(state, false)
@@ -208,13 +208,13 @@ func (k Kubernetes) SRV(zone string, state middleware.State) (records []dns.RR,
 			}
 			// k.AAA(zone, state1, nil) as well...?
 		case ip.To4() != nil:
-			serv.Host = k.Domain(serv.Key)
+			serv.Host = serv.Key
 			srv := serv.NewSRV(state.QName(), weight)
 
 			records = append(records, srv)
 			extra = append(extra, serv.NewA(srv.Target, ip.To4()))
 		case ip.To4() == nil:
-			serv.Host = k.Domain(serv.Key)
+			serv.Host = serv.Key
 			srv := serv.NewSRV(state.QName(), weight)
 
 			records = append(records, srv)
@@ -226,17 +226,17 @@ func (k Kubernetes) SRV(zone string, state middleware.State) (records []dns.RR,
 
 // Returning MX records from kubernetes not implemented.
 func (k Kubernetes) MX(zone string, state middleware.State) (records []dns.RR, extra []dns.RR, err error) {
-    return nil, nil, err
+	return nil, nil, err
 }
 
 // Returning CNAME records from kubernetes not implemented.
 func (k Kubernetes) CNAME(zone string, state middleware.State) (records []dns.RR, err error) {
-    return nil, err
+	return nil, err
 }
 
 // Returning TXT records from kubernetes not implemented.
 func (k Kubernetes) TXT(zone string, state middleware.State) (records []dns.RR, err error) {
-    return nil, err
+	return nil, err
 }
 
 func (k Kubernetes) NS(zone string, state middleware.State) (records, extra []dns.RR, err error) {
@@ -259,11 +259,11 @@ func (k Kubernetes) NS(zone string, state middleware.State) (records, extra []dn
 		case ip == nil:
 			return nil, nil, fmt.Errorf("NS record must be an IP address: %s", serv.Host)
 		case ip.To4() != nil:
-			serv.Host = k.Domain(serv.Key)
+			serv.Host = serv.Key
 			records = append(records, serv.NewNS(state.QName()))
 			extra = append(extra, serv.NewA(serv.Host, ip.To4()))
 		case ip.To4() == nil:
-			serv.Host = k.Domain(serv.Key)
+			serv.Host = serv.Key
 			records = append(records, serv.NewNS(state.QName()))
 			extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
 		}