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

1 files changed, 6 insertions, 3 deletions

diff --git a/middleware/kubernetes/handler.go b/middleware/kubernetes/handler.go
index 44de8da3d..168b65508 100644
--- a/middleware/kubernetes/handler.go
+++ b/middleware/kubernetes/handler.go
@@ -11,15 +11,15 @@ import (
 
 func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 
-    fmt.Println("[debug] here entering ServeDNS: ctx:%v dnsmsg:%v", ctx, r)
+	fmt.Printf("[debug] here entering ServeDNS: ctx:%v dnsmsg:%v\n", ctx, r)
 
 	state := middleware.State{W: w, Req: r}
 	if state.QClass() != dns.ClassINET {
 		return dns.RcodeServerFailure, fmt.Errorf("can only deal with ClassINET")
 	}
 
-    // Check that query matches one of the zones served by this middleware,
-    // otherwise delegate to the next in the pipeline.
+	// Check that query matches one of the zones served by this middleware,
+	// otherwise delegate to the next in the pipeline.
 	zone := middleware.Zones(k.Zones).Matches(state.Name())
 	if zone == "" {
 		if k.Next == nil {
@@ -43,6 +43,9 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
 		records, err = k.AAAA(zone, state, nil)
 	case "TXT":
 		records, err = k.TXT(zone, state)
+		// TODO: change lookup to return appropriate error. Then add code below
+		// this switch to check for the error and return not implemented.
+		//return dns.RcodeNotImplemented, nil
 	case "CNAME":
 		records, err = k.CNAME(zone, state)
 	case "MX":