File Settings should return error in case the file itself does not exist

infrastructure/file_settings_source.go

@@ -35,6 +35,9 @@ func NewFileSettingsSource(
 }
 
 func (s *FileSettingsSource) PublicSSHKeyForUsername(string) (string, error) {
+	if !s.fs.FileExists(s.settingsFilePath) {
+		return "", bosherr.Errorf("File for settings source does not exist: '%s'", s.settingsFilePath)
+	}
 	return "", nil
 }
 

infrastructure/file_settings_source_test.go

@@ -26,10 +26,32 @@ var _ = Describe("FileSettingsSource", func() {
 	})
 
 	Describe("PublicSSHKeyForUsername", func() {
-		It("returns an empty string", func() {
-			publicKey, err := source.PublicSSHKeyForUsername("fake-username")
-			Expect(err).ToNot(HaveOccurred())
-			Expect(publicKey).To(Equal(""))
+		Context("when the settings file exists", func() {
+			BeforeEach(func() {
+				settingsFileName := "/fake-settings-file-path"
+				source = infrastructure.NewFileSettingsSource(settingsFileName, fs, logger)
+				err := fs.WriteFileString(settingsFileName, "{}")
+				Expect(err).NotTo(HaveOccurred())
+			})
+
+			It("returns an empty string", func() {
+				publicKey, err := source.PublicSSHKeyForUsername("fake-username")
+				Expect(err).ToNot(HaveOccurred())
+				Expect(publicKey).To(Equal(""))
+			})
+		})
+
+		Context("when the settings file does not exist", func() {
+			BeforeEach(func() {
+				source = infrastructure.NewFileSettingsSource("/missing-settings-file-path", fs, logger)
+			})
+
+			It("returns an error with the file path", func() {
+				_, err := source.PublicSSHKeyForUsername("fake-username")
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("File for settings source does not exist"))
+				Expect(err.Error()).To(ContainSubstring("/missing-settings-file-path"))
+			})
 		})
 	})
 

infrastructure/multi_settings_source.go

@@ -42,6 +42,7 @@ func (s *MultiSettingsSource) PublicSSHKeyForUsername(username string) (string,
 			s.selectedSSHKeySource = source
 			return publicSSHKey, nil
 		}
+		s.logger.Warn("multi-settings-source", "Failed to get public SSH key from source: %v", err)
 	}
 
 	return "", bosherr.WrapErrorf(err, "Getting public SSH key for '%s'", username)

infrastructure/multi_settings_source_test.go

@@ -85,6 +85,11 @@ var _ = Describe("MultiSettingsSource", func() {
 					Expect(err).ToNot(HaveOccurred())
 					Expect(publicKey).To(Equal("fake-public-key-2"))
 				})
+
+				It("logs a warning for the first source", func() {
+					_, _ = source.PublicSSHKeyForUsername("fake-username") //nolint:errcheck
+					Expect(logBuffer.String()).To(ContainSubstring("fake-public-key-err-1"))
+				})
 			})
 
 			Context("when both sources fail to get ssh key", func() {
@@ -93,6 +98,11 @@ var _ = Describe("MultiSettingsSource", func() {
 					Expect(err).To(HaveOccurred())
 					Expect(err.Error()).To(ContainSubstring("fake-public-key-err-2"))
 				})
+
+				It("logs a warning for the first source", func() {
+					_, _ = source.PublicSSHKeyForUsername("fake-username") //nolint:errcheck
+					Expect(logBuffer.String()).To(ContainSubstring("fake-public-key-err-1"))
+				})
 			})
 		})