Run golint on pkg/haproxy/*.go, and fix to make golint happy.

For the most part by adding go docs, and by using Go naming
conventions in a few cases.

Remove some commented-out code while we're here.

Makefile

@@ -68,6 +68,7 @@ check: build
 	golint ./pkg/controller/...
 	golint ./pkg/interfaces/...
 	golint ./pkg/varnish/...
+	golint ./pkg/haproxy/...
 	golint ./pkg/apis/varnishingress/v1alpha1/...
 	golint ./cmd/...
 	go test -v ./pkg/controller/... ./pkg/interfaces/... ./pkg/varnish/...

pkg/haproxy/faccess.go

@@ -33,6 +33,8 @@ import (
 	"net/url"
 )
 
+// FaccessError encapsulates an error response from an faccess server.
+// Satisfies the error interface.
 type FaccessError struct {
 	Status int
 	PEM    string
@@ -42,11 +44,22 @@ func (err FaccessError) Error() string {
 	return err.PEM + ": " + http.StatusText(err.Status)
 }
 
+// FaccessClient sends requests to an http-faccess server to determine
+// if a file exists and is readable. This is used to find out when a
+// PEM file exists (as projected into a SecretVolume), so that haproxy
+// can be reloaded with the TLS certificate in its configuration.
+//
+//	https://code.uplex.de/testing/http-faccess
 type FaccessClient struct {
 	baseURL *url.URL
 	client  *http.Client
 }
 
+// NewFaccessClient returns a client for the http-faccess server
+// listening at host.
+//
+// host may have the form "addr" or "addr:port", where addr may be a
+// host name or IP address.
 func NewFaccessClient(host string) *FaccessClient {
 	return &FaccessClient{
 		baseURL: &url.URL{
@@ -61,6 +74,10 @@ func (client *FaccessClient) getHost() string {
 	return client.baseURL.Host
 }
 
+// PEMExists returns true iff the http-faccess server reports that the
+// PEM file corresponding to spec exists and is readable.
+//
+// A non-nil error return may wrap FaccessError.
 func (client *FaccessClient) PEMExists(spec SecretSpec) (bool, error) {
 	relPath := &url.URL{Path: spec.CertName()}
 	url := client.baseURL.ResolveReference(relPath)