Add DebugInfo() API and put the information on /validate

container/docker/factory.go

@@ -149,6 +149,10 @@ func (self *dockerFactory) CanHandleAndAccept(name string) (bool, bool, error) {
 	return true, canAccept, nil
 }
 
+func (self *dockerFactory) DebugInfo() map[string][]string {
+	return map[string][]string{}
+}
+
 func parseDockerVersion(full_version_string string) ([]int, error) {
 	version_regexp_string := "(\\d+)\\.(\\d+)\\.(\\d+)"
 	version_re := regexp.MustCompile(version_regexp_string)

container/factory.go

@@ -30,6 +30,9 @@ type ContainerHandlerFactory interface {
 
 	// Name of the factory.
 	String() string
+
+	// Returns debugging information. Map of lines per category.
+	DebugInfo() map[string][]string
 }
 
 // TODO(vmarmol): Consider not making this global.
@@ -90,3 +93,17 @@ func ClearContainerHandlerFactories() {
 
 	factories = make([]ContainerHandlerFactory, 0, 4)
 }
+
+func DebugInfo() map[string][]string {
+	factoriesLock.RLock()
+	defer factoriesLock.RUnlock()
+
+	// Get debug information for all factories.
+	out := make(map[string][]string)
+	for _, factory := range factories {
+		for k, v := range factory.DebugInfo() {
+			out[k] = v
+		}
+	}
+	return out
+}

container/factory_test.go

@@ -31,6 +31,10 @@ func (self *mockContainerHandlerFactory) String() string {
 	return self.Name
 }
 
+func (self *mockContainerHandlerFactory) DebugInfo() map[string][]string {
+	return map[string][]string{}
+}
+
 func (self *mockContainerHandlerFactory) CanHandleAndAccept(name string) (bool, bool, error) {
 	return self.CanHandleValue, self.CanAcceptValue, nil
 }

manager/manager.go

@@ -107,6 +107,9 @@ type Manager interface {
 
 	// Get details about interesting docker images.
 	DockerImages() ([]DockerImage, error)
+
+	// Returns debugging information. Map of lines per category.
+	DebugInfo() map[string][]string
 }
 
 // New takes a memory storage and returns a new manager.
@@ -1131,3 +1134,7 @@ func (m *manager) DockerInfo() (DockerStatus, error) {
 	}
 	return out, nil
 }
+
+func (m *manager) DebugInfo() map[string][]string {
+	return container.DebugInfo()
+}

validate/validate.go

@@ -313,6 +313,13 @@ func HandleRequest(w http.ResponseWriter, containerManager manager.Manager) erro
 
 	ioSchedulerValidation, desc := validateIoScheduler(containerManager)
 	out += fmt.Sprintf(OutputFormat, "Block device setup", ioSchedulerValidation, desc)
+
+	// Output debug info.
+	debugInfo := containerManager.DebugInfo()
+	for category, lines := range debugInfo {
+		out += fmt.Sprintf(OutputFormat, category, "", strings.Join(lines, "\n\t"))
+	}
+
 	_, err = w.Write([]byte(out))
 	return err
 }