Watch the htpasswd file for changes and update the htpasswdMap (#1701)

* dynamically update the htpasswdMap based on the changes made to the htpasswd file

* added tests to validate that htpasswdMap is updated after the htpasswd file is changed

* refactored `htpasswd` and `watcher` to lower cognitive complexity

* returned errors and refactored tests

* added `CHANGELOG.md` entry for #1701 and fixed the codeclimate issue

* Apply suggestions from code review

Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>

* Fix lint issue from code suggestion

* Wrap htpasswd load and watch errors with context

* add the htpasswd wrapped error context to the test

Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>

pkg/authentication/basic/htpasswd_test.go

@@ -1,8 +1,11 @@
 package basic
 
 import (
+	"os"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
+	. "github.com/onsi/gomega/types"
 )
 
 const (
@@ -84,13 +87,89 @@ var _ = Describe("HTPasswd Suite", func() {
 				})
 
 				It("returns an error", func() {
-					Expect(err).To(MatchError("could not open htpasswd file: open ./test/htpasswd-doesnt-exist.txt: no such file or directory"))
+					Expect(err).To(MatchError("could not load htpasswd file: could not open htpasswd file: open ./test/htpasswd-doesnt-exist.txt: no such file or directory"))
 				})
 
 				It("returns a nil validator", func() {
 					Expect(validator).To(BeNil())
 				})
 			})
+
+			Context("htpasswd file is updated", func() {
+				const filePathPrefix = "htpasswd-file-updated-"
+				const adminUserHtpasswdEntry = "admin:$2y$05$SXWrNM7ldtbRzBvUC3VXyOvUeiUcP45XPwM93P5eeGOEPIiAZmJjC"
+				const user1HtpasswdEntry = "user1:$2y$05$/sZYJOk8.3Etg4V6fV7puuXfCJLmV5Q7u3xvKpjBSJUka.t2YtmmG"
+				var fileNames []string
+
+				AfterSuite(func() {
+					for _, v := range fileNames {
+						err := os.Remove(v)
+						Expect(err).ToNot(HaveOccurred())
+					}
+
+				})
+
+				type htpasswdUpdate struct {
+					testText              string
+					remove                bool
+					expectedLen           int
+					expectedGomegaMatcher GomegaMatcher
+				}
+
+				assertHtpasswdMapUpdate := func(hu htpasswdUpdate) {
+					var validator Validator
+					var file *os.File
+					var err error
+
+					// Create a temporary file with at least one entry
+					file, err = os.CreateTemp("", filePathPrefix)
+					Expect(err).ToNot(HaveOccurred())
+					_, err = file.WriteString(adminUserHtpasswdEntry + "\n")
+					Expect(err).ToNot(HaveOccurred())
+
+					validator, err = NewHTPasswdValidator(file.Name())
+					Expect(err).ToNot(HaveOccurred())
+
+					htpasswd, ok := validator.(*htpasswdMap)
+					Expect(ok).To(BeTrue())
+
+					if hu.remove {
+						// Overwrite the original file with another entry
+						err = os.WriteFile(file.Name(), []byte(user1HtpasswdEntry+"\n"), 0644)
+						Expect(err).ToNot(HaveOccurred())
+					} else {
+						// Add another entry to the original file in append mode
+						_, err = file.WriteString(user1HtpasswdEntry + "\n")
+						Expect(err).ToNot(HaveOccurred())
+					}
+
+					err = file.Close()
+					Expect(err).ToNot(HaveOccurred())
+
+					fileNames = append(fileNames, file.Name())
+
+					It("has the correct number of users", func() {
+						Expect(len(htpasswd.users)).To(Equal(hu.expectedLen))
+					})
+
+					It(hu.testText, func() {
+						Expect(htpasswd.Validate(adminUser, adminPassword)).To(hu.expectedGomegaMatcher)
+					})
+
+					It("new entry is present", func() {
+						Expect(htpasswd.Validate(user1, user1Password)).To(BeTrue())
+					})
+				}
+
+				Context("htpasswd entry is added", func() {
+					assertHtpasswdMapUpdate(htpasswdUpdate{"initial entry is present", false, 2, BeTrue()})
+				})
+
+				Context("htpasswd entry is removed", func() {
+					assertHtpasswdMapUpdate(htpasswdUpdate{"initial entry is removed", true, 1, BeFalse()})
+				})
+
+			})
 		})
 	})
 })