Use lables when resetting logger levels

Take into consideration the labels when resetting the logger levels.
We don't want to reset all the logger levels if we're using a singular
global logger.

context.go

@@ -73,12 +73,12 @@ func (c *Context) GetAllLoggerTags() []string {
 			names[k] = v
 		}
 	}
-	labels := make([]string, 0, len(names))
+	tags := make([]string, 0, len(names))
 	for name := range names {
-		labels = append(labels, name)
+		tags = append(tags, name)
 	}
-	sort.Strings(labels)
-	return labels
+	sort.Strings(tags)
+	return tags
 }
 
 func (c *Context) getLoggerModule(name string, tags []string) *module {
@@ -214,15 +214,22 @@ func (c *Context) ApplyConfig(config Config, labels ...Labels) {
 
 // ResetLoggerLevels iterates through the known logging modules and sets the
 // levels of all to UNSPECIFIED, except for <root> which is set to WARNING.
-func (c *Context) ResetLoggerLevels() {
+// If labels are provided, then only loggers that have the provided labels
+// will be reset.
+func (c *Context) ResetLoggerLevels(labels ...Labels) {
+	label := mergeLabels(labels)
+
 	c.modulesMutex.Lock()
 	defer c.modulesMutex.Unlock()
+
 	// Setting the root module to UNSPECIFIED will set it to WARNING.
 	for _, module := range c.modules {
+		if !module.hasLabelIntersection(label) {
+			continue
+		}
+
 		module.setLevel(UNSPECIFIED)
 	}
-	// We can safely just wipe everything here.
-	c.modulesTagConfig = make(map[string]Level)
 }
 
 func (c *Context) write(entry Entry) {

context_test.go

@@ -261,7 +261,7 @@ func (*ContextSuite) TestApplyConfigTags(c *gc.C) {
 		})
 }
 
-func (*ContextSuite) TestApplyConfigLabelsAppliesToNewLoggers(c *gc.C) {
+func (*ContextSuite) TestApplyConfigTagsAppliesToNewLoggers(c *gc.C) {
 	context := loggo.NewContext(loggo.WARNING)
 
 	context.ApplyConfig(loggo.Config{"#one": loggo.TRACE})
@@ -289,7 +289,7 @@ func (*ContextSuite) TestApplyConfigLabelsAppliesToNewLoggers(c *gc.C) {
 		})
 }
 
-func (*ContextSuite) TestApplyConfigLabelsAppliesToNewLoggersWithMultipleTags(c *gc.C) {
+func (*ContextSuite) TestApplyConfigTagsAppliesToNewLoggersWithMultipleTags(c *gc.C) {
 	context := loggo.NewContext(loggo.WARNING)
 
 	// Invert the order here, to ensure that the config order doesn't matter,
@@ -312,7 +312,7 @@ func (*ContextSuite) TestApplyConfigLabelsAppliesToNewLoggersWithMultipleTags(c
 		})
 }
 
-func (*ContextSuite) TestApplyConfigLabelsResetLoggerLevels(c *gc.C) {
+func (*ContextSuite) TestApplyConfigTagsResetLoggerLevels(c *gc.C) {
 	context := loggo.NewContext(loggo.WARNING)
 
 	context.ApplyConfig(loggo.Config{"#one": loggo.TRACE})
@@ -339,7 +339,93 @@ func (*ContextSuite) TestApplyConfigLabelsResetLoggerLevels(c *gc.C) {
 		})
 }
 
-func (*ContextSuite) TestApplyConfigTagsAddative(c *gc.C) {
+func (*ContextSuite) TestApplyConfigTagsResetLoggerLevelsUsingLabels(c *gc.C) {
+	context := loggo.NewContext(loggo.WARNING)
+
+	context.ApplyConfig(loggo.Config{"#one": loggo.TRACE})
+	context.ApplyConfig(loggo.Config{"#two": loggo.DEBUG})
+
+	context.GetLogger("a", "one").ChildWithLabels("b", loggo.Labels{"x": "y"})
+	context.GetLogger("c.d", "one")
+	context.GetLogger("e", "two")
+
+	// If a label is available on a logger, then resetting the levels should
+	// not remove the label.
+
+	context.ResetLoggerLevels()
+
+	c.Assert(context.Config(), gc.DeepEquals,
+		loggo.Config{
+			"": loggo.WARNING,
+		})
+	c.Assert(context.CompleteConfig(), gc.DeepEquals,
+		loggo.Config{
+			"":    loggo.WARNING,
+			"a":   loggo.UNSPECIFIED,
+			"a.b": loggo.UNSPECIFIED,
+			"c":   loggo.UNSPECIFIED,
+			"c.d": loggo.UNSPECIFIED,
+			"e":   loggo.UNSPECIFIED,
+		})
+}
+
+func (*ContextSuite) TestApplyConfigTagsResetLoggerLevelsUsingLabelsRemoval(c *gc.C) {
+	context := loggo.NewContext(loggo.WARNING)
+
+	context.ApplyConfig(loggo.Config{"#one": loggo.TRACE})
+	context.ApplyConfig(loggo.Config{"#two": loggo.DEBUG})
+
+	context.GetLogger("a", "one").ChildWithLabels("b", loggo.Labels{"x": "y"}).ChildWithTags("g", "one")
+	context.GetLogger("c.d", "one")
+	context.GetLogger("e", "two")
+	context.GetLogger("f")
+
+	// Ensure that the logger that matches exactly the label is removed,
+	// including it's children. So we observe hierarchy in the removal.
+
+	c.Assert(context.Config(), gc.DeepEquals,
+		loggo.Config{
+			"":      loggo.WARNING,
+			"a":     loggo.TRACE,
+			"a.b.g": loggo.TRACE,
+			"c.d":   loggo.TRACE,
+			"e":     loggo.DEBUG,
+		})
+	c.Assert(context.CompleteConfig(), gc.DeepEquals,
+		loggo.Config{
+			"":      loggo.WARNING,
+			"a":     loggo.TRACE,
+			"a.b":   loggo.UNSPECIFIED,
+			"a.b.g": loggo.TRACE,
+			"c":     loggo.UNSPECIFIED,
+			"c.d":   loggo.TRACE,
+			"e":     loggo.DEBUG,
+			"f":     loggo.UNSPECIFIED,
+		})
+
+	context.ResetLoggerLevels(loggo.Labels{"x": "y"})
+
+	c.Assert(context.Config(), gc.DeepEquals,
+		loggo.Config{
+			"":    loggo.WARNING,
+			"a":   loggo.TRACE,
+			"c.d": loggo.TRACE,
+			"e":   loggo.DEBUG,
+		})
+	c.Assert(context.CompleteConfig(), gc.DeepEquals,
+		loggo.Config{
+			"":      loggo.WARNING,
+			"a":     loggo.TRACE,
+			"a.b":   loggo.UNSPECIFIED,
+			"a.b.g": loggo.UNSPECIFIED,
+			"c":     loggo.UNSPECIFIED,
+			"c.d":   loggo.TRACE,
+			"e":     loggo.DEBUG,
+			"f":     loggo.UNSPECIFIED,
+		})
+}
+
+func (*ContextSuite) TestApplyConfigTagsAdditive(c *gc.C) {
 	context := loggo.NewContext(loggo.WARNING)
 	context.ApplyConfig(loggo.Config{"#one": loggo.TRACE})
 	context.ApplyConfig(loggo.Config{"#two": loggo.DEBUG})

logger.go

@@ -112,6 +112,11 @@ func (logger Logger) Tags() []string {
 	return logger.getModule().tags
 }
 
+// Labels returns the configured labels of the logger's module.
+func (logger Logger) Labels() Labels {
+	return logger.getModule().labels
+}
+
 // EffectiveLogLevel returns the effective min log level of
 // the receiver - that is, messages with a lesser severity
 // level will be discarded.
@@ -140,15 +145,6 @@ func (logger Logger) Logf(level Level, message string, args ...interface{}) {
 	logger.LogCallf(2, level, message, args...)
 }
 
-// LogWithlabelsf logs a printf-formatted message at the given level with extra
-// labels. The given labels will be added to the log entry.
-// A message will be discarded if level is less than the the effective log level
-// of the logger. Note that the writers may also filter out messages that are
-// less than their registered minimum severity level.
-func (logger Logger) LogWithLabelsf(level Level, message string, extraLabels map[string]string, args ...interface{}) {
-	logger.logCallf(2, level, message, extraLabels, args...)
-}
-
 // LogCallf logs a printf-formatted message at the given level.
 // The location of the call is indicated by the calldepth argument.
 // A calldepth of 1 means the function that called this function.
@@ -157,12 +153,12 @@ func (logger Logger) LogWithLabelsf(level Level, message string, extraLabels map
 // Note that the writers may also filter out messages that
 // are less than their registered minimum severity level.
 func (logger Logger) LogCallf(calldepth int, level Level, message string, args ...interface{}) {
-	logger.logCallf(calldepth+1, level, message, nil, args...)
+	logger.logCallf(calldepth+1, level, message, args...)
 }
 
 // logCallf is a private method for logging a printf-formatted message at the
 // given level. Used by LogWithLabelsf and LogCallf.
-func (logger Logger) logCallf(calldepth int, level Level, message string, extraLabels map[string]string, args ...interface{}) {
+func (logger Logger) logCallf(calldepth int, level Level, message string, args ...interface{}) {
 	module := logger.getModule()
 	if !module.willWrite(level) {
 		return
@@ -205,10 +201,6 @@ func (logger Logger) logCallf(calldepth int, level Level, message string, extraL
 	for k, v := range logger.impl.labels {
 		entry.Labels[k] = v
 	}
-	// Add extra labels if there's any given.
-	for k, v := range extraLabels {
-		entry.Labels[k] = v
-	}
 	module.write(entry)
 }
 

logger_test.go

@@ -36,6 +36,29 @@ func (s *LoggerSuite) TestInheritedLabels(c *gc.C) {
 
 	logger := context.GetLogger("testing")
 
+	nestedLoggerWithLabels := logger.
+		ChildWithLabels("nested", loggo.Labels{"foo": "bar"})
+	deepNestedLoggerWithLabels := nestedLoggerWithLabels.
+		ChildWithLabels("nested", loggo.Labels{"foo": "baz"}).
+		ChildWithLabels("deepnested", loggo.Labels{"fred": "tim"})
+
+	loggerWithTagsAndLabels := logger.
+		ChildWithLabels("nested-labels", loggo.Labels{"hello": "world"}).
+		ChildWithTags("nested-tag", "tag1", "tag2")
+
+	c.Check(nestedLoggerWithLabels.Labels(), gc.DeepEquals, loggo.Labels{"foo": "bar"})
+	c.Check(deepNestedLoggerWithLabels.Labels(), gc.DeepEquals, loggo.Labels{"foo": "baz", "fred": "tim"})
+	c.Check(loggerWithTagsAndLabels.Labels(), gc.DeepEquals, loggo.Labels{"hello": "world"})
+}
+
+func (s *LoggerSuite) TestInheritedLabelsInLogs(c *gc.C) {
+	writer := &loggo.TestWriter{}
+	context := loggo.NewContext(loggo.INFO)
+	err := context.AddWriter("test", writer)
+	c.Assert(err, gc.IsNil)
+
+	logger := context.GetLogger("testing")
+
 	nestedLoggerWithLabels := logger.
 		ChildWithLabels("nested", loggo.Labels{"foo": "bar"})
 	deepNestedLoggerWithLabels := nestedLoggerWithLabels.